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Sample records for alkaline anaerobic respiration

  1. Metabolic interactions between methanogenic consortia and anaerobic respiring bacteria

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  2. Molecular AND logic gate based on bacterial anaerobic respiration.

    Science.gov (United States)

    Arugula, Mary Anitha; Shroff, Namita; Katz, Evgeny; He, Zhen

    2012-10-21

    Enzyme coding genes that integrate information for anaerobic respiration in Shewanella oneidensis MR-1 were used as input for constructing an AND logic gate. The absence of one or both genes inhibited electrochemically-controlled anaerobic respiration, while wild type bacteria were capable of accepting electrons from an electrode for DMSO reduction.

  3. Cholera Toxin Production Induced upon Anaerobic Respiration is Suppressed by Glucose Fermentation in Vibrio cholerae.

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    Oh, Young Taek; Lee, Kang-Mu; Bari, Wasimul; Kim, Hwa Young; Kim, Hye Jin; Yoon, Sang Sun

    2016-03-01

    The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

  4. Activation of cholera toxin production by anaerobic respiration of trimethylamine N-oxide in Vibrio cholerae.

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    Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-Il; Yoon, Sang Sun

    2012-11-16

    Vibrio cholerae is a gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2',7'-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor.

  5. Predicting Phosphorus Release from Anaerobic, Alkaline, Flooded Soils.

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    Amarawansha, Geethani; Kumaragamage, Darshani; Flaten, Don; Zvomuya, Francis; Tenuta, Mario

    2016-07-01

    Anaerobic conditions induced by prolonged flooding often lead to an enhanced release of phosphorus (P) to floodwater; however, this effect is not consistent across soils. This study aimed to develop an index to predict P release potential from alkaline soils under simulated flooded conditions. Twelve unamended or manure-amended surface soils from Manitoba were analyzed for basic soil properties, Olsen P (Ols-P), Mehlich-3 extractable total P (M3P), Mehlich-3 extractable molybdate-reactive P (M3P), water extractable P (WEP), soil P fractions, single-point P sorption capacity (P), and Mehlich-3 extractable Ca (M3Ca), and Mg (M3Mg). Degree of P saturation (DPS) was calculated using Ols-P, M3P or M3P as the intensity factor, and an estimated adsorption maximum based on either P or M3Ca + M3Mg as the capacity factor. To develop the model, we used the previously reported floodwater dissolved reactive P (DRP) concentration changes during 8 wk of flooding for the same unamended and manured soils. Relative changes in floodwater DRP concentration (DRP), calculated as the ratio of maximum to initial DRP concentration, ranged from 2 to 15 across ten of the soils, but were ≤1.5 in the two soils with the greatest clay content. Partial least squares analysis indicated that DPS3 calculated using M3P as the intensity factor and (2 × P) + M3P as the capacity factor with clay percentage can effectively predict DRP ( = 0.74). Results suggest that P release from a soil to floodwater may be predicted using simple and easily measurable soil properties measured before flooding, but validation with more soils is needed.

  6. The regulatory role of ferric uptake regulator (Fur during anaerobic respiration of Shewanella piezotolerans WP3.

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    Xin-Wei Yang

    Full Text Available Ferric uptake regulator (Fur is a global regulator that controls bacterial iron homeostasis. In this study, a fur deletion mutant of the deep-sea bacterium Shewanella piezotolerans WP3 was constructed. Physiological studies revealed that the growth rate of this mutant under aerobic conditions was only slightly lower than that of wild type (WT, but severe growth defects were observed under anaerobic conditions when different electron acceptors (EAs were provided. Comparative transcriptomic analysis demonstrated that Fur is involved not only in classical iron homeostasis but also in anaerobic respiration. Fur exerted pleiotropic effects on the regulation of anaerobic respiration by controlling anaerobic electron transport, the heme biosynthesis system, and the cytochrome c maturation system. Biochemical assays demonstrated that levels of c-type cytochromes were lower in the fur mutant, consistent with the transcriptional profiling. Transcriptomic analysis and electrophoretic mobility shift assays revealed a primary regulation network for Fur in WP3. These results suggest that Fur may act as a sensor for anoxic conditions to trigger and influence the anaerobic respiratory system.

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

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

    1997-05-01

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

  8. Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

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    Jin, Guang; Bierma, Tom; Walker, Paul M

    2014-01-01

    This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

  9. Anaerobic respiration: In vitro efficacy of Nitazoxanide against mitochondriate Acanthamoeba castellanii of the T4 genotype.

    Science.gov (United States)

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Farooq, Maria; Khan, Naveed Ahmed

    2015-10-01

    Acanthamoeba is an opportunistic protist pathogen that is responsible for serious human and animal infection. Being one of the most frequently isolated protists from the environment, it is likely that it readily encounters microaerophilic environments. For respiration under anaerobic or low oxygen conditions in several amitochondriate protists, decarboxylation of pyruvate is catalyzed by pyruvate ferredoxin oxidoreductase instead of pyruvate dehydrogenase. In support, Nitazoxanide, an inhibitor of pyruvate ferredoxin oxidoreductase, is effective and non-mutagenic clinically against a range of amitochondriate protists, Giardia intestinalis, Entamoeba histolytica and Trichomonas vaginalis. The overall aim of the present study was to determine in vitro efficacy of Nitazoxanide against Acanthamoeba castellanii. At micromolar concentrations, the findings revealed that Nitazoxanide neither affected A. castellanii growth or viability nor amoeba-mediated host cell monolayer damage in vitro or extracellular proteolytic activities. Similarly, microaerophilic conditions alone had no significant effects. In contrast, microaerophilic conditions together with Nitazoxanide showed amoebicidal effects and inhibited A. castellanii-mediated host cell monolayer damage as well as extracellular proteases. Using encystation assays, it was observed that Nitazoxanide inhibited trophozoite transformation into cysts both under aerophilic and microaerophilic conditions. Furthermore, pre-treatment of cysts with Nitazoxanide inhibited A. castellanii excystation. These findings are important in the identification of potential targets that could be useful against parasite-specific respiration as well as to understand the basic biology of the life cycle of Acanthamoeba.

  10. Effects of alkalinity sources on the stability of anaerobic digestion from food waste.

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    Chen, Shujun; Zhang, Jishi; Wang, Xikui

    2015-11-01

    This study investigated the effects of some alkalinity sources on the stability of anaerobic digestion (AD) from food waste (FW). Four alkalinity sources, namely lime mud from papermaking (LMP), waste eggshell (WES), CaCO3 and NaHCO3, were applied as buffer materials and their stability effects were evaluated in batch AD. The results showed that LMP and CaCO3 had more remarkable effects than NaHCO3 and WES on FW stabilization. The methane yields were 120.2, 197.0, 156.2, 251.0 and 194.8 ml g(-1) VS for the control and synergistic digestions of CaCO3, NaHCO3, LMP and WES added into FW, respectively. The corresponding final alkalinity reached 5906, 7307, 9504, 7820 and 6782 mg l(-1), while the final acidities were determined to be 501, 200, 50, 350 and 250 mg l(-1), respectively. This indicated that the synergism between alkalinity and inorganic micronutrients from different alkalinity sources played an important role in the process stability of AD from FW.

  11. The anaerobic corrosion of carbon steel in alkaline media – Phase 2 results

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    Fennell P.A.H.

    2013-07-01

    Full Text Available In the Belgian Supercontainer concept a carbon steel overpack will surround high-level waste and spent fuel containers and be encased in a cementitious buffer material. A programme of research was carried out to investigate and measure the rate of anaerobic corrosion of carbon steel in an artificial alkaline porewater that simulates the aqueous phase in the cementitious buffer material. The corrosion rates were measured by monitoring hydrogen evolution using a manometric gas cell technique and by applying electrochemical methods. Phase 2 of the programme has repeated and extended previous Phase 1 measurements of the effects of radiation, temperature and chloride concentration of the anaerobic corrosion rate. This paper provides an update on the results from Phase 2 of the programme. The results confirm previous conclusions that the long-term corrosion rate of carbon steel in alkaline simulated porewater is determined by the formation of a thin barrier layer and a thicker outer layer composed of magnetite. Anaerobic corrosion of steel in cement requires an external supply of water.

  12. Cholera toxin production during anaerobic trimethylamine N-oxide respiration is mediated by stringent response in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M; Lee, Kang-Mu; Yoon, Sang Sun

    2014-05-09

    As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae.

  13. Anaerobic digestion of poplar processing residues for methane production after alkaline treatment.

    Science.gov (United States)

    Yao, Yiqing; He, Mulan; Ren, Yubing; Ma, Liying; Luo, Yang; Sheng, Hongmei; Xiang, Yun; Zhang, Hua; Li, Qien; An, Lizhe

    2013-04-01

    Poplar processing residues were used for methane production by anaerobic digestion after alkaline treatment and methane production was measured. The highest methane production of 271.9 L/kg volatile solid (VS) was obtained at conditions of 35 g/L and 5.0% NaOH, which was 113.8% higher than non-alkaline treated samples, and 28.9% higher than that of corn straw, which is the conventional anaerobic digestion material in China. The maximal enhancement of 275.5% obtained at conditions of 50 g/L and 7.0% NaOH. Degradation of cellulose, hemicellulose and lignin after treatment increased by 4.0-9.0%, 3.3-6.2%, and 11.1-20.5%, respectively, with NaOH dose ranged from 3.0% to 7.0%. Scanning electron microscopy (SEM), FTIR spectra and Crystallinity measurements showed that the lignocellulosic structures were disrupted by NaOH. The results indicate poplar processing residues might be an efficient substrate for methane production after alkaline treatment.

  14. Enhanced coproduction of hydrogen and methane from cornstalks by a three-stage anaerobic fermentation process integrated with alkaline hydrolysis.

    Science.gov (United States)

    Cheng, Xi-Yu; Liu, Chun-Zhao

    2012-01-01

    A three-stage anaerobic fermentation process including H(2) fermentation I, H(2) fermentation II, methane fermentation was developed for the coproduction of hydrogen and methane from cornstalks. Hydrogen production from cornstalks using direct microbial conversion by Clostridium thermocellum 7072 was markedly enhanced in the two-stage thermophilic hydrogen fermentation process integrated with alkaline treatment. The highest total hydrogen yield from cornstalks in the two-stage fermentation process reached 74.4 mL/g-cornstalk. The hydrogen fermentation effluents and alkaline hydrolyzate were further used for methane fermentation by anaerobic granular sludge, and the total methane yield reached 205.8 mL/g-cornstalk. The total energy recovery in the three-stage anaerobic fermentation process integrated with alkaline hydrolysis reached 70.0%.

  15. Anaerobic digestion of the microalga Spirulina at extreme alkaline conditions: biogas production, metagenome, and metatranscriptome

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    Nolla-Ardèvol, Vímac; Strous, Marc; Tegetmeyer, Halina E.

    2015-01-01

    A haloalkaline anaerobic microbial community obtained from soda lake sediments was used to inoculate anaerobic reactors for the production of methane rich biogas. The microalga Spirulina was successfully digested by the haloalkaline microbial consortium at alkaline conditions (pH 10, 2.0 M Na+). Continuous biogas production was observed and the obtained biogas was rich in methane, up to 96%. Alkaline medium acted as a CO2 scrubber which resulted in low amounts of CO2 and no traces of H2S in the produced biogas. A hydraulic retention time (HRT) of 15 days and 0.25 g Spirulina L−1 day−1 organic loading rate (OLR) were identified as the optimal operational parameters. Metagenomic and metatranscriptomic analysis showed that the hydrolysis of the supplied substrate was mainly carried out by Bacteroidetes of the “ML635J-40 aquatic group” while the hydrogenotrophic pathway was the main producer of methane in a methanogenic community dominated by Methanocalculus. PMID:26157422

  16. Application of urea dosing for alkalinity supply during anaerobic digestion of vinasse.

    Science.gov (United States)

    Boncz, M A; Formagini, E L; Santos, L da S; Marques, R D; Paulo, P L

    2012-01-01

    Pushed by demand for renewable energy, the ethanol industry in Brazil is expanding. However, production of 1 m(3) of ethanol generates around 13 m(3) of liquid residues (vinasse), so this expansion results in an increasing need for a more adequate destination of these residues. Nowadays the vinasse is dispersed on the sugar cane fields in the practice of fertirrigation, but anaerobic digestion of this residue may be a better solution, additionally offering an alternative source of energy, able to complement hydroelectric power supply in the dry season. However, when trying to digest vinasse at reduced hydraulic retention times, complications arise from its strong tendency toward acidification, upsetting the fragile balance of transformations normally occurring under anaerobic conditions. For successful operation of an anaerobic treatment process with acceptable hydraulic residence times, increasing alkalinity levels inside the reactor is neces-sary. In the present work we show that pH regulation by means of urea dosing, in spite of the risk posed by ammonia toxicity towards methanogenic biomass, can be a viable alternative to avoid vinasse acidification. The ammonia formed in urea conversion remains in solution, rather than escaping to the biogas, and so its use as fertiliser can offset its cost of application in the process.

  17. Enhanced solid-state anaerobic digestion of corn stover by alkaline pretreatment.

    Science.gov (United States)

    Zhu, Jiying; Wan, Caixia; Li, Yebo

    2010-10-01

    Alkaline pretreatment was applied to enhance biogas production from corn stover through solid-state anaerobic digestion. Different NaOH loadings (1%, 2.5%, 5.0% and 7.5% (w/w)) were tested for solid-state pretreatment of corn stover. Lignin degradation during pretreatment increased from 9.1% to 46.2% when NaOH concentration increased from 1.0% to 7.5%. The NaOH-pretreated corn stover was digested using effluent of liquid anaerobic digestion as inoculum and nitrogen source. NaOH loading of 1% did not cause significant improvement on biogas yield. The highest biogas yield of 372.4 L/kg VS was obtained with 5% NaOH-pretreated corn stover, which was 37.0% higher than that of the untreated corn stover. However, a higher NaOH loading of 7.5% caused faster production of volatile fatty acids during the hydrolysis and acidogenesis stages, which inhibited the methanogenesis. Simultaneous NaOH treatment and anaerobic digestion did not significantly improve the biogas production (P>0.05).

  18. Metabolic potential of fatty acid oxidation and anaerobic respiration by abundant members of Thaumarchaeota and Thermoplasmata in deep anoxic peat

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xueju [Georgia Inst. of Technology, Atlanta, GA (United States); Handley, Kim M. [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Gilbert, Jack A. [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Marine Biological Lab., Woods Hole, MA (United States); Zhejiang Univ., Hangzhou (China); Kostka, Joel E. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-05-22

    To probe the metabolic potential of abundant Archaea in boreal peats, we reconstructed two near-complete archaeal genomes, affiliated with Thaumarchaeota group 1.1c (bin Fn1, 8% abundance), which was a genomically unrepresented group, and Thermoplasmata (bin Bg1, 26% abundance), from metagenomic data acquired from deep anoxic peat layers. Each of the near-complete genomes encodes the potential to degrade long-chain fatty acids (LCFA) via β-oxidation. Fn1 has the potential to oxidize LCFA either by syntrophic interaction with methanogens or by coupling oxidation with anaerobic respiration using fumarate as a terminal electron acceptor (TEA). Fn1 is the first Thaumarchaeota genome without an identifiable carbon fixation pathway, indicating that this mesophilic phylum encompasses more diverse metabolisms than previously thought. Furthermore, we report genetic evidence suggestive of sulfite and/or organosulfonate reduction by Thermoplasmata Bg1. In deep peat, inorganic TEAs are often depleted to extremely low levels, yet the anaerobic respiration predicted for two abundant archaeal members suggests organic electron acceptors such as fumarate and organosulfonate (enriched in humic substances) may be important for respiration and C mineralization in peatlands.

  19. Enhancement of thermophilic anaerobic digestion of thickened waste activated sludge by combined microwave and alkaline pretreatment

    Institute of Scientific and Technical Information of China (English)

    Yongzhi Chi; Yuyou Li; Xuening Fei; Shaopo Wang; Hongying Yun

    2011-01-01

    Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency.Uniform design was applied to determine the combination of target temperature (110-210℃),microwave holding time (1-51 min),and NaOH dose (0-2.5 g NaOH/g suspended solids (SS)) in terms of their effect on volatile suspended solids (VSS) solubilization.Maximum solubilization ratio (85.1%) of VSS was observed at 210℃ with 0.2 g-NaOH/g-SS and 35 min holding time.The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch reactors by monitoring cumulative methane production (CMP).Improvements in methane production in the TWAS were directly related to the microwave and alkaline pretreatment of the sludge.The highest CMP was a 27% improvement over the control.In spite of the increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge,a semi-continuous thennophilic reactor fed with pretreated TWAS without neutralization (at 170℃ with 1 rain holding time and 0.05 g NaOH/g SS) was stable and functioned well,with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%,respectively,which were higher than those of the control system.Additionally,methane yields (L@STP/g-CODadded,at standard temperature and pressure (STP) conditions of 0℃ and 101.325 kPa) and (L@STP/g VSadded) increased by 17% and 13%,respectively,compared to the control reactor.

  20. Low-heat alkaline pretreatment of biomass for dairy anaerobic codigestion.

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    Jin, Guang; Bierma, Tom

    2014-01-01

    In this research, low-heat alkaline pretreatment was evaluated to determine the extent to which urban landscape waste (yard waste), corn stover, and switchgrass could be codigested under conditions typical of US farm-based anaerobic digestion (AD). Waste heat from combined heat and power (CHP) units associated with AD could make such pretreatment economical. Short-term batch digestion studies and 8-week continuous-feed studies were used to screen and evaluate various pretreatment conditions. Results indicate that maple and oak leaves did not digest well, even with pretreatment. Pretreatment did improve digestion of corn leaves and stalks as well as switchgrass. However, these materials also digested reasonably well even without pretreatment. No digester operational problems were observed during continuous-feed studies of intermittently stirred bench top digesters, but optimal levels of alkali, temperature, and pretreatment time may be specific to the feedstock, particle size, and digester loading rate. Results suggest that some common lignocellulosic biomass materials, such as corn stover and switchgrass, could be successfully codigested in many existing farm-based digesters. Interestingly, without pretreatment, switchgrass digestion improved over 20-fold when digested with seed culture from a dairy digester compared to seed culture from a municipal digester, suggesting that culture acclimation could be as important as pretreatment in improving digestion of specific lignocellulosic feedstocks.

  1. Volatile fatty acids production from anaerobic treatment of cassava waste water: effect of temperature and alkalinity.

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    Hasan, Salah Din Mahmud; Giongo, Citieli; Fiorese, Mônica Lady; Gomes, Simone Damasceno; Ferrari, Tatiane Caroline; Savoldi, Tarcio Enrico

    2015-01-01

    The production of volatile fatty acids (VFAs), intermediates in the anaerobic degradation process of organic matter from waste water, was evaluated in this work. A batch reactor was used to investigate the effect of temperature, and alkalinity in the production of VFAs, from the fermentation of industrial cassava waste water. Peak production of total volatile fatty acids (TVFAs) was observed in the first two days of acidogenesis. A central composite design was performed, and the highest yield (3400 mg L(-1) of TVFA) was obtained with 30°C and 3 g L(-1) of sodium bicarbonate. The peak of VFA was in 45 h (pH 5.9) with a predominance of acetic (63%) and butyric acid (22%), followed by propionic acid (12%). Decreases in amounts of cyanide (12.9%) and chemical oxygen demand (21.6%) were observed, in addition to the production of biogas (0.53 cm(3) h(-1)). The process was validated experimentally and 3400 g L(-1) of TVFA were obtained with a low relative standard deviation.

  2. The contribution of genes required for anaerobic respiration to the virulence of Salmonella enterica serovar Gallinarum for chickens

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    J.B. Paiva

    2009-12-01

    Full Text Available Salmonella enterica serovar Gallinarum (SG is an intracellular pathogen of chickens. To survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. The fumarate reductase (frdABCD, dimethyl sulfoxide (DMSO-trimethylamine N-oxide (TMAO reductase (dmsABC, and nitrate reductase (narGHIJ operons in Salmonella Typhimurium (STM encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. In this study mortality rates of chickens challenged with mutants of Salmonella Gallinarum, which were defective in utilising anaerobic electron acceptors, were assessed in comparison to group of bird challenged with wild strain. The greatest degree of attenuation was observed with mutations affecting nitrate reductase (napA, narG with additional attenuations induced by a mutation affecting fumarate reductase (frdA and a double mutant (dmsA torC affecting DMSO and TMAO reductase.

  3. Quinone-respiration improves dechlorination of carbon tetrachloride by anaerobic sludge

    NARCIS (Netherlands)

    Cervantes, F.J.; Vu-Thi-Thu, L.; Lettinga, G.; Field, J.A.

    2004-01-01

    The impact of humic acids and the humic model compound, anthraquinone-2,6-disulfonate (AQDS), on the biodegradation of carbon tetrachloride (CT) by anaerobic granular sludge was studied. Addition of both humic acids and AQDS at sub-stoichiometric levels increased the first-order rate of conversion o

  4. Proteomic analysis of Neisseria gonorrhoeae biofilms shows shift to anaerobic respiration and changes in nutrient transport and outermembrane proteins.

    Directory of Open Access Journals (Sweden)

    Nancy J Phillips

    Full Text Available Neisseria gonorrhoeae, the causative agent of gonorrhea, can form biofilms in vitro and in vivo. In biofilms, the organism is more resistant to antibiotic treatment and can serve as a reservoir for chronic infection. We have used stable isotope labeling by amino acids in cell culture (SILAC to compare protein expression in biofilm and planktonic organisms. Two parallel populations of N. gonorrhoeae strain 1291, which is an arginine auxotroph, were grown for 48 h in continuous-flow chambers over glass, one supplemented with (13C(6-arginine for planktonic organisms and the other with unlabeled arginine for biofilm growth. The biofilm and planktonic cells were harvested and lysed separately, and fractionated into three sequential protein extracts. Corresponding heavy (H planktonic and light (L biofilm protein extracts were mixed and separated by 1D SDS-PAGE gels, and samples were extensively analyzed by liquid chromatography-mass spectrometry. Overall, 757 proteins were identified, and 152 unique proteins met a 1.5-fold cutoff threshold for differential expression with p-values <0.05. Comparing biofilm to planktonic organisms, this set included 73 upregulated and 54 downregulated proteins. Nearly a third of the upregulated proteins were involved in energy metabolism, with cell envelope proteins making up the next largest group. Of the downregulated proteins, the largest groups were involved in protein synthesis and energy metabolism. These proteomics results were compared with our previously reported results from transcriptional profiling of gonococcal biofilms using microarrays. Nitrite reductase and cytochrome c peroxidase, key enzymes required for anaerobic growth, were detected as highly upregulated in both the proteomic and transcriptomic datasets. These and other protein expression changes observed in the present study were consistent with a shift to anaerobic respiration in gonococcal biofilms, although changes in membrane proteins not

  5. Physiological roles of ArcA, Crp, and EtrA and their interactive control on aerobic and anaerobic respiration in Shewanella oneidensis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Haichun [Zhejiang University; Wang, Xiaohu [Baylor College of Medicine, Huston; Chen, Jingrong [University of Oklahoma, Norman; Liang, Yili [University of Oklahoma, Norman; Chen, Haijiang [Zhejiang University; Palzkill, Timothy [Baylor College of Medicine, Huston; Zhou, Jizhong [University of Oklahoma

    2010-01-01

    In the genome of Shewanella oneidensis, genes encoding the global regulators ArcA, Crp, and EtrA have been identified. All these proteins deviate from their counterparts in E. coli significantly in terms of functionality and regulon. It is worth investigating the involvement and relationship of these global regulators in aerobic and anaerobic respiration in S. oneidensis. In this study, the impact of the transcriptional factors ArcA, Crp, and EtrA on aerobic and anaerobic respiration in S. oneidensis were assessed. While all these proteins appeared to be functional in vivo, the importance of individual proteins in these two major biological processes differed. The ArcA transcriptional factor was critical in aerobic respiration while the Crp protein was indispensible in anaerobic respiration. Using a newly developed reporter system, it was found that expression of arcA and etrA was not influenced by growth conditions but transcription of crp was induced by removal of oxygen. An analysis of the impact of each protein on transcription of the others revealed that Crp expression was independent of the other factors whereas ArcA repressed both etrA and its own transcription while EtrA also repressed arcA transcription. Transcriptional levels of arcA in the wild type, crp, and etrA strains under either aerobic or anaerobic conditions were further validated by quantitative immunoblotting with a polyclonal antibody against ArcA. This extensive survey demonstrated that all these three global regulators are functional in S. oneidensis. In addition, the reporter system constructed in this study will facilitate in vivo transcriptional analysis of targeted promoters.

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

    Science.gov (United States)

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

    2001-12-01

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

  7. Transcriptional regulation of metabolic pathways, alternative respiration and enterotoxin genes in anaerobic growth of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2009-01-01

    Aims: To assess genes specifically activated during anaerobic growth that are involved in metabolism and pathogenesis of the foodborne pathogen Bacillus cereus. Methods and Results: Growth under anaerobic conditions in Brain Heart Infusion (BHI) broth revealed a reduced growth rate and lower yield a

  8. Anaerobic respiration and antioxidant responses of Corythucha ciliata (Say) adults to heat-induced oxidative stress under laboratory and field conditions.

    Science.gov (United States)

    Ju, Rui-Ting; Wei, He-Ping; Wang, Feng; Zhou, Xu-Hui; Li, Bo

    2014-03-01

    High temperature often induces oxidative stress and antioxidant response in insects. This phenomenon has been well documented under controlled laboratory conditions, but whether it happens under fluctuating field conditions is largely unknown. In this study, we used an invasive lace bug (Corythucha ciliata) as a model species to compare the effects of controlled thermal treatments (2 h at 33-43 °C with 2 °C intervals in the laboratory) and naturally fluctuating thermal conditions (08:00-14:00 at 2-h intervals (29.7-37.2 °C) on a hot summer day in a field in Shanghai, China) on lipid peroxidation (malondialdehyde (MDA) was the marker) and anaerobic respiration (lactate dehydrogenase (LDH) was the marker), as well as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione reductase (GR). The results show that MDA concentration increased significantly in response to heat stresses with similar trend in the laboratory and field. LDH activities did not significantly vary across temperatures in the laboratory-exposed individuals, but they significantly increased by rising temperature in the field. The activities or concentrations of SOD, CAT, GSH, and GR all significantly increased with increasing temperature in the two populations. These findings indicate that high temperature induces oxidative stress, resulting in high anaerobic respiration and antioxidant defenses in C. ciliata under both the laboratory and field conditions, which likely provide a defense mechanism against oxidative damage due to the accumulation of ROS.

  9. Use of cassava wastewater treated anaerobically with alkaline agents as fertilizer for maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Ferreira Ribas

    2010-02-01

    Full Text Available The wastewater of the processing of cassava's flour (manipueira was submitted to the anaerobic treatment in two phases: acidogenic and methanogenic. In the acidogenic phase, the wastewater was stabilized with NaOH (ASH and with limestone (ASL. After that, both stabilized effluents were treated by a methanogenic reactor. Then, the effluent of the methanogenic reactor was used as fertilizer on maize in the initial growth stage (30 days, cultivated in pots in a greenhouse. The treatments were T1: control without urea addition (only N from soil; T2: NPK (2.2 g of urea with 45% of N; T3: ASH (84 mL.kg soil-1; T4: ASL (102 mL.kg soil-1; T5: double dose ASH (168 mL.kg soil-1 and T6: double dose ASL (204 mL.kg soil-1. Each treatment was composed by 4 plants/pot in five repetitions. It was observed that all the treatments with stabilized wastewater had favorable effect to the soil pH (> than 7.5 and basis saturation (V% in the soil around to 90%. The performances of nitrogen absorption by the maize plants were 64, 54, 80 and 78% for T3, T4, T5 and T6, respectively.A água residuária do processamento de farinha de mandioca (manipueira foi submetida ao tratamento anaeróbio em duas fases: acidogênica e metanogênica. Na fase acidogênica, a água residuária foi estabilizada com NaOH (ASH e com calcário (ASL. Em seguida, ambos efluentes estabilizados foram tratados por um reator metanogênico. Então, o efluente do reator metanogênico foi usado como fertilizante no milho no estádio inicial de crescimento (30 dias cultivado em vaso em casa de vegetação. Os tratamentos foram T1: controle sem uréia (somente N do solo; T2: NPK (2,2 g de uréia com 45% de N; T3: ASH (84 mL.kg solo-1; T4: ASL (102 mL.kg solo-1; T5: dose dupla de ASH (168 mL.kg solo-1 e T6: dose dupla de ASL (204 mL.kg solo-1. Cada tratamento foi composto por 4 plantas/vaso com 5 repetições. Foi observado que todos os tratamentos com á água residuária estabilizada tiveram efeitos

  10. Comparative genomic analysis of regulation of anaerobic respiration in ten genomes from three families of gamma-proteobacteria (Enterobacteriaceae, Pasteurellaceae, Vibrionaceae

    Directory of Open Access Journals (Sweden)

    Mironov Andrey A

    2007-02-01

    Full Text Available Abstract Background Gamma-proteobacteria, such as Escherichia coli, can use a variety of respiratory substrates employing numerous aerobic and anaerobic respiratory systems controlled by multiple transcription regulators. Thus, in E. coli, global control of respiration is mediated by four transcription factors, Fnr, ArcA, NarL and NarP. However, in other Gamma-proteobacteria the composition of global respiration regulators may be different. Results In this study we applied a comparative genomic approach to the analysis of three global regulatory systems, Fnr, ArcA and NarP. These systems were studied in available genomes containing these three regulators, but lacking NarL. So, we considered several representatives of Pasteurellaceae, Vibrionaceae and Yersinia spp. As a result, we identified new regulon members, functioning in respiration, central metabolism (glycolysis, gluconeogenesis, pentose phosphate pathway, citrate cicle, metabolism of pyruvate and lactate, metabolism of carbohydrates and fatty acids, transcriptional regulation and transport, in particular: the ATP synthase operon atpIBEFHAGCD, Na+-exporting NADH dehydrogenase operon nqrABCDEF, the D-amino acids dehydrogenase operon dadAX. Using an extension of the comparative technique, we demonstrated taxon-specific changes in regulatory interactions and predicted taxon-specific regulatory cascades. Conclusion A comparative genomic technique was applied to the analysis of global regulation of respiration in ten gamma-proteobacterial genomes. Three structurally different but functionally related regulatory systems were described. A correlation between the regulon size and the position of a transcription factor in regulatory cascades was observed: regulators with larger regulons tend to occupy top positions in the cascades. On the other hand, there is no obvious link to differences in the species' lifestyles and metabolic capabilities.

  11. Comparative Genomics Analysis and Phenotypic Characterization of Shewanella putrefaciens W3-18-1: Anaerobic Respiration, Bacterial Microcompartments, and Lateral Flagella

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, D.; Tu, Q.; He, Zhili; Zhou, Jizhong

    2010-05-17

    Respiratory versatility and psychrophily are the hallmarks of Shewanella. The ability to utilize a wide range of electron acceptors for respiration is due to the large number of c-type cytochrome genes present in the genome of Shewanella strains. More recently the dissimilatory metal reduction of Shewanella species has been extensively and intensively studied for potential applications in the bioremediation of radioactive wastes of groundwater and subsurface environments. Multiple Shewanella genome sequences are now available in the public databases (Fredrickson et al., 2008). Most of the sequenced Shewanella strains were isolated from marine environments and this genus was believed to be of marine origin (Hau and Gralnick, 2007). However, the well-characterized model strain, S. oneidensis MR-1, was isolated from the freshwater lake sediment of Lake Oneida, New York (Myers and Nealson, 1988) and similar bacteria have also been isolated from other freshwater environments (Venkateswaran et al., 1999). Here we comparatively analyzed the genome sequence and physiological characteristics of S. putrefaciens W3-18-1 and S. oneidensis MR-1, isolated from the marine and freshwater lake sediments, respectively. The anaerobic respirations, carbon source utilization, and cell motility have been experimentally investigated. Large scale horizontal gene transfers have been revealed and the genetic divergence between these two strains was considered to be critical to the bacterial adaptation to specific habitats, freshwater or marine sediments.

  12. Asparagus stem as a new lignocellulosic biomass feedstock for anaerobic digestion: increasing hydrolysis rate, methane production and biodegradability by alkaline pretreatment.

    Science.gov (United States)

    Chen, Xiaohua; Gu, Yu; Zhou, Xuefei; Zhang, Yalei

    2014-07-01

    Recently, anaerobic digestion of lignocellulosic biomass for methane production has attracted considerable attention. However, there is little information regarding methane production from asparagus stem, a typical lignocellulosic biomass, by anaerobic digestion. In this study, alkaline pretreatment of asparagus stem was investigated for its ability to increase hydrolysis rate and methane production and to improve biodegradability (BD). The hydrolysis rate increased with increasing NaOH dose, due to higher removal rates of lignin and hemicelluloses. However, the optimal NaOH dose was 6% (w/w) according to the specific methane production (SMP). Under this condition, the SMP and the technical digestion time of the NaOH-treated asparagus stem were 242.3 mL/g VS and 18 days, which were 38.4% higher and 51.4% shorter than those of the untreated sample, respectively. The BD was improved from 40.1% to 55.4%. These results indicate that alkaline pretreatment could be an efficient method for increasing methane production from asparagus stem.

  13. Aggregatibacter actinomycetemcomitans QseBC is activated by catecholamines and iron and regulates genes encoding proteins associated with anaerobic respiration and metabolism

    Science.gov (United States)

    Weigel, WA; Demuth, DR; Torres-Escobar, A; Juárez-Rodríguez, MD

    2015-01-01

    Aggregatibacter actinomycetemcomitans QseBC regulates its own expression and is essential for biofilm growth and virulence. However, the signal that activates the QseC sensor has not been identified and the qseBC regulon has not been defined. In this study, we show that QseC is activated by catecholamine hormones and iron but not by either component alone. Activation of QseC requires an EYRDD motif in the periplasmic domain of the sensor and site-specific mutations in EYRDD or the deletion of the periplasmic domain inhibits catecholamine/iron-dependent induction of the ygiW-qseBC operon. Catecholamine/iron-dependent induction of transcription also requires interaction of the QseB response regulator with its binding site in the ygiW-qseBC promoter. Whole genome microarrays were used to compare gene expression profiles of A. actinomycetemcomitans grown in a chemically defined medium with and without catecholamine and iron supplementation. Approximately 11.5% of the A. actinomycetemcomitans genome was differentially expressed by at least two-fold upon exposure to catecholamines and iron. The expression of ferritin was strongly induced, suggesting that intracellular iron storage capacity is increased upon QseBC activation. Consistent with this, genes encoding iron binding and transport proteins were down-regulated by QseBC. Strikingly, 57% of the QseBC up-regulated genes (56/99) encode proteins associated with anaerobic metabolism and respiration. Most of these up-regulated genes were recently reported to be induced during in vivo growth of A. actinomycetemcomitans. These results suggest that detection of catecholamines and iron by QseBC may alter the cellular metabolism of A. actinomycetemcomitans for increased fitness and growth in an anaerobic host environment. PMID:25923132

  14. Effects of pH, acidity and alkalinity on the microbiota activity of an anaerobic sludge blanket reactor (UASB treating pigmanure effluents

    Directory of Open Access Journals (Sweden)

    Fabricio Moterani

    2009-12-01

    Full Text Available The anaerobic processes used for treating wastewater have been often applied mainly for optimizing treatment systems. Among many of these systems, the UASB is one of the most successfully used. This type of reactor presents a good condition for microorganisms development, and therefore, for organic matter degradation. As a result, the goal of this research was to evaluate the effect of parameters, such as: temperature, pH, acidity and alkalinity on the microorganisms consortia, acclimatized in an UASB reactor, and simultaneously, observing the sludge morphology through a scanning electronic microscopy (SEM, in order to identify the response of the bacteria consortia under this environmental circumstances. The biomass operated under a mesophilic temperature, varying from 190C to 210C. The maximum concentration of volatile acids was 100 mg L-1, and the volumetric organic loading rate was 59 kgCOD m-3d-1. The total alkalinity concentration values were between 2500 and 5550 mgCaCO3 L-1. The average pH value of the sludge was 7.3. Under these conditions it was observed the development of a well acclimatized granular biomass, composed mainly of filamentous bacteria.

  15. Anaerobic methanethiol degradation and methanogenic community analysis in an alkaline (pH 10) biological process for liquefied petroleum gas desulfurization

    NARCIS (Netherlands)

    Leerdam, van R.C.; Bonilla-Salinas, M.; Bok, de F.A.M.; Bruning, H.; Lens, P.N.L.; Stams, A.J.M.; Janssen, A.J.H.

    2008-01-01

    Anaerobic methanethiol (MT) degradation by mesophilic (30 degrees C) alkaliphilic (pH 10) communities was studied in a lab-scale Upflow Anaerobic Sludge Bed (UASB) reactor inoculated with a mixture of sediments from the Wadden Sea (The Netherlands), Soap Lake (Central Washington), and Russian soda l

  16. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue

    2016-01-01

    of interaction, which have not been sufficiently studied so far. It is therefore important to understand how choosing operational parameters can influence reactor performances. The current study highlights the interaction offermentative bacteria and exoelectrogens in the integrated system....... in an integrated system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) for waste activated sludge (WAS). Microbial communities in integrated system would build a thorough energetic and metabolic interaction network regarding fermentation communities and electrode respiring communities...... investigated the interaction of fermentation communities and electrode respiring communities in an integrated system of WAS fermentation and MEC for hydrogen recovery. A high energy recovery was achieved in the MECs feeding WAS fermentation liquid through alkaline pretreatment. Some anaerobes belonging...

  17. Can soil respiration estimate neglect the contribution of abiotic exchange?

    Institute of Scientific and Technical Information of China (English)

    Xi CHEN; WenFeng WANG; GePing LUO; Hui YE

    2014-01-01

    This study examines the hypothesis that soil respiration can always be interpreted purely in terms of biotic processes, neglecting the contribution of abiotic exchange to CO2 fluxes in alkaline soils of arid areas that characterize 5%of the Earth’s total land surface. Analyses on flux data collected from previous studies suggested reconciling soil respiration as organic (root/microbial respiration) and inorganic (abiotic CO2 exchange) respiration, whose contributions in the total CO2 flux were determined by soil alkaline content. On the basis of utilizing mete-orological and soil data collected from the Xinjiang and Central Asia Scientific Data Sharing Platform, an incorpo-rated model indicated that inorganic respiration represents almost half of the total CO2 flux. Neglecting the abiotic module may result in overestimates of soil respiration in arid alkaline lands, which partly explains the long-sought“missing carbon sink”.

  18. Effect of pH and Alkalinity on Operation of Anaerobic Baffled Reactor%pH值和碱度对厌氧折流板反应器运行的影响

    Institute of Scientific and Technical Information of China (English)

    刘宇红; 曲颖; 宋虹苇; 于晓英

    2012-01-01

    为考察pH值和碱度对厌氧折流板反应器(ABR)高效、稳定运行的影响,采用一个有效容积为28 L的4格室ABR反应器处理豆制品废水.ABR反应器运行72 d的结果表明:在启动阶段的前期外加碱液调节进水pH值,使pH值和碱度分别基本稳定在6.0 ~7.0和1 000~1 300mg/L,运行效果良好.启动45 d时,停止外加碱液对进水pH值进行调节,系统仍稳定运行,但启动阶段出现丙酸浓度缓慢上升现象.在反应器稳定运行阶段,各格室的pH值分别为(4.5 ~6.0)、(5.5 ~6.8)、(6.8 ~7.2)、(7.1 ~7.3),碱度基本处在1 000 ~1 400 mg/L,反应器出水的发酵产物含量< 100 mg/L(乙酸占90%以上),对COD的去除率保持在90%以上.%A 4-compartment anaerobic baffled reactor (ABR) with an effective volume of 28 L was used to treat soybean processing wastewater. The influence of pH and alkalinity on the operation of ABR was investigated. The operation results for 72 d indicated that the reactor attained good operation effect in the early stage of start-up by adding alkaline to the influent. pH and alkalinity were controlled at 6.0 to 7.0 and 1 000 to 1 300 mg/L, respectively. After 45 d of startup without adding alkalinity to control pH of the influent, the reactor could also run well. However, slow increase of propionic acid in the start-up stage was observed. In continuous operation stage of ABR, the pH of each compartment was 4.5 to 6.0, 5.5 to 6.8, 6.8 to 7.2, and 7.1 to 7.3, and the alkalinity was 1 000 mg/L to 1 400 mg/L. The fermentation product in the effluent was less than 100 mg/L (acetic acid was more than 90% ) , and the removal rate of COD was above 90%.

  19. RESPONSE OF RICE ROOT IN RESPIRATION AT JOINTING STAGE TO OZONE POLLUTION AND ALTERNATION OF ANAEROBIC AND AEROBIC CONDITIONS%水稻拔节期根系呼吸对臭氧污染和厌氧—有氧环境变化的响应

    Institute of Scientific and Technical Information of China (English)

    寇太记; 朱建国

    2013-01-01

    Effects of elevated atmospheric ozone (pO3) (50% higher than the ambient pO3 in concentration) on root respiration and biomass accumulation and distribution of rice (Oryza sativa L.cv.Xiandao 63) at the jointing stage were investigated in fully open-air field conditions,and effect of alternation of anaerobic and aerobic conditions on root respiration was analyzed using special gas-collecting installations.Results show that under elevated pO3canopy and total biomass of the crop decreased slightly,while its root dry matter weight and ratio of root/canopy dropped significantly by 14.7% and 10.4%,respectively.The mixture of N2 and O2at a ratio of 9∶1 or 9.5∶0.5 was the most propitious for root respiration,whereas in pure N2,natural air and CO2-saturated distilled water root respiration rate was lowered to a varying degree.The treatment of elevated pO3 coupled with measurement inn CO2-saturated distilled water and the treatment of ambient air coupled with measurement in pure N2 was the least in root respiration rate,indicating that although the condition in which root respiration was measured affected root respiration rate,the impact was restricted in degree by the atmospheric environment in which the plant grew.The root respiration rate of rice growing under elevated ozone was 23.6% ~52.7% higher than that under natural atmosphere when measured in pure gas condition,and the difference between the two was insignificant when the measurement was done in CO2-saturated distilled water,showing that the influence of ozone pollution on root respiration obviously decreased.Under elevated and ambient pO3 environments,root respiration of the rice displayed a curve of convex quadratic function with increasing oxygen supply in the gaseous environment for measurement.The oxygen concentration of 5%~ 10% in the environment promoted rice root respiration,while stronge anaerobic condition (i.e.,pure N2) and aerobic conditions (i.e.,air) both affected root

  20. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

    DEFF Research Database (Denmark)

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

    2015-01-01

    denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off...... suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100%) in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein....

  1. Anaerobic bacteria

    Science.gov (United States)

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

  2. Development of a Molecular System for Studying Microbial Arsenate Respiration

    Science.gov (United States)

    Saltikov, C. W.; Newman, D. K.

    2002-12-01

    The toxic element arsenic is a major contaminant of many groundwaters and surface waters throughout the world. Arsenic enrichment is primarily of geological origin resulting from weathering processes and geothermal activity. Not surprisingly, microorganisms inhabiting anoxic arsenic-contaminated environments have evolved to exploit arsenate during respiration. Numerous bacteria have been isolated that use arsenate as a terminal electron acceptor for respiratory growth. The diversity of this metabolism appears to be widespread throughout the microbial tree of life, suggesting respiratory arsenate reduction is ancient in origin. Yet little is known about the molecular mechanisms for how these organisms respire arsenate. We have developed a model system in Shewanella trabarsenatis, strain ANA-3, a facultative anaerobe that respires arsenate and tolerates high concentrations of arsenite (10 mM). Through loss-of-function studies, we have identified genes involved in both arsenic resistance and arsenate respiration. The genes that confer resistance to arsenic are homologous to the well-characterized ars operon of E. coli. However, the respiratory arsenate reductase is predicted to encode a novel protein that shares homologous regions (~ 40 % similarity) to molybdopterin anaerobic reductases specific for DMSO, thiosulfate, nitrate, and polysulfide. I will discuss our emerging model for how strain ANA-3 respires arsenate and the relationship between arsenite resistance and arsenate respiration. I will also highlight the relevance of this type of analysis for biogeochemical studies.

  3. Respirator Fact Sheet

    Science.gov (United States)

    ... have expiration dates that should be checked before purchase. Also, over time your mask can get old ... Respirator Fact Sheet [PDF - 706 KB] Follow NIOSH Facebook Flickr Pinterest Twitter YouTube NIOSH Homepage NIOSH A- ...

  4. Respiration in Aquatic Insects.

    Science.gov (United States)

    MacFarland, John

    1985-01-01

    This article: (1) explains the respiratory patterns of several freshwater insects; (2) describes the differences and mechanisms of spiracular cutaneous, and gill respiration; and (3) discusses behavioral aspects of selected aquatic insects. (ML)

  5. Anaerobic fermentation mixture from waste activated sludge under alkaline condition improving treatment effect of wastewater with low C/N%剩余污泥厌氧发酵混合物提高低C/N污水处理效果

    Institute of Scientific and Technical Information of China (English)

    刘晔; 王淑莹; 袁悦; 何岳兰; 彭永臻

    2016-01-01

    Direct discharging of high nitrogen and phosphorus concentration wastewater can bring serious eutrophication to the environment. The activated sludge process has been widely used for solving this problem. However, the process exhibits poor removal of nitrogen and phosphorus due to the shortage of carbon source, and also produces a lot of waste activated sludge (WAS) which needed to be treated and disposed. On the basis of these considerations above, anaerobic fermentation of WAS and fermentation liquid utilization processes were developed. However, fermentation liquid separation from fermented sludge was difficult and had high energy consumption. To avoid the problem of liquid-solid separation difficulty involved in traditional WAS anaerobic fermentation liquid utilization process, the feasibility of using fermentation mixture directly as external carbon source for nitrogen and phosphorus removal of wastewater treatment was discussed. Firstly, the characteristics of anaerobic fermentation mixture under the acidic (pH value of 4), neutral (pH value uncontrolled) and alkaline (pH value of 10) conditions over 90 days were compared. Secondly, biological denitrification and biological phosphorus removal processes by adding alkaline fermentation mixture of different volumes were investigated. A set ofsequencing batch reactors (SBR) were respectively fed with 0.5 L seed sludge and 0.5 L wastewater, and then alkaline fermentation mixture of 0, 10, 20, 30, 50, 100 and 200 mL were added into the 7 reactors. The feasibility of using anaerobic fermentation mixture from WAS under alkaline condition as external carbon source was indicated by nitrate nitrogen (NO3--N) removal efficiency and pure phosphorus release amount.Meanwhile, the influence of ammonia (NH4+-N) concentration on biological nitrification process was analyzed. The results indicated that: 1) Alkaline fermentation mixture showed the best merit of reusable carbon source, with soluble chemical oxygen demand (SCOD

  6. Teaching Cellular Respiration & Alternate Energy Sources with a Laboratory Exercise Developed by a Scientist-Teacher Partnership

    Science.gov (United States)

    Briggs, Brandon; Mitton, Teri; Smith, Rosemary; Magnuson, Timothy

    2009-01-01

    Microbial fuel cells are a current research area that harvests electricity from bacteria capable of anaerobic respiration. Graphite is an electrically conductive material that bacteria can respire on, thus it can be used to capture electrons from bacteria. When bacteria transfer electrons to graphite, an electrical potential is created that can…

  7. Anaerobic mineralization of toluene by enriched sediments with quinones and humus as terminal electron acceptors

    NARCIS (Netherlands)

    Cervantes, F.J.; Dijksma, W.; Duong-Dac, T.; Ivanova, A.; Lettinga, G.; Field, J.A.

    2001-01-01

    The anaerobic microbial oxidation of toluene to CO2 coupled to humus respiration was demonstrated by use of enriched anaerobic sediments from the Amsterdam petroleum harbor (APH) and the Rhine River. Both highly purified soil humic acids (HPSHA) and the humic quinone moiety model compound anthraquin

  8. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

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

  9. Perspectives of the microbial carbon pump with special references to microbial respiration and ecological efficiency

    Directory of Open Access Journals (Sweden)

    H. Dang

    2014-01-01

    Full Text Available Although respiration consumes fixed carbon and produce CO2, it provides energy for essential biological processes of an ecosystem, including the microbial carbon pump (MCP. In MCP-driving biotransformation of labile DOC to recalcitrant DOC (RDOC, microbial respiration provides the metabolic energy for environmental organic substrate sensing, cellular enzyme syntheses and catalytic processes such as uptake, secretion, modification, fixation and storage of carbon compounds. The MCP efficiency of a heterotrophic microorganism is thus related to its energy production efficiency and hence to its respiration efficiency. Anaerobically respiring microbes usually have lower energy production efficiency and lower energy-dependent carbon transformation efficiency, and consequently lower MCP efficiency at per cell level. This effect is masked by the phenomena that anoxic environments often store more organic matter. Here we point out that organic carbon preservation and RDOC production is different in mechanisms, and anaerobically respiring ecosystems could also have lower MCP ecological efficiency. Typical cases can be found in large river estuarine ecosystems. Due to strong terrigenous input of nutrients and organic matter, estuarine ecosystems usually experience intense heterotrophic respiration processes that rapidly consume dissolved oxygen, potentially producing hypoxic and anoxic zones in the water column. The lowered availability of dissolved oxygen and the excessive supply of nutrients such as nitrate from river input prompt enhanced anaerobic respiration processes. Thus, some nutrients may be consumed by anaerobically respiring heterotrophic microorganisms, instead of being utilized by phytoplankton for carbon fixation and primary production. In this situation, the ecological functioning of the estuarine ecosystem is altered and the ecological efficiency is lowered, as less carbon is fixed and less energy is produced. Ultimately this would have

  10. Cattle respiration facility

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Lund, Peter; Weisbjerg, Martin Riis

    2012-01-01

    In Denmark, the emission rate of methane from dairy cows has been calculated using the IPCC standard values for dairy cows in Western countries, due to the lack of national data. Therefore, four respiration chambers for dairy cows were built with the main purpose of measuring methane, but also...

  11. Anaerobic Thermophiles

    Directory of Open Access Journals (Sweden)

    Francesco Canganella

    2014-02-01

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

  12. Anaerobic growth of a "strict aerobe" (Bacillus subtilis).

    Science.gov (United States)

    Nakano, M M; Zuber, P

    1998-01-01

    There was a long-held belief that the gram-positive soil bacterium Bacillus subtilis is a strict aerobe. But recent studies have shown that B. subtilis will grow anaerobically, either by using nitrate or nitrite as a terminal electron acceptor, or by fermentation. How B. subtilis alters its metabolic activity according to the availability of oxygen and alternative electron acceptors is but one focus of study. A two-component signal transduction system composed of a sensor kinase, ResE, and a response regulator, ResD, occupies an early stage in the regulatory pathway governing anaerobic respiration. One of the essential roles of ResD and ResE in anaerobic gene regulation is induction of fnr transcription upon oxygen limitation. FNR is a transcriptional activator for anaerobically induced genes, including those for respiratory nitrate reductase, narGHJI.B. subtilis has two distinct nitrate reductases, one for the assimilation of nitrate nitrogen and the other for nitrate respiration. In contrast, one nitrite reductase functions both in nitrite nitrogen assimilation and nitrite respiration. Unlike many anaerobes, which use pyruvate formate lyase, B. subtilis can carry out fermentation in the absence of external electron acceptors wherein pyruvate dehydrogenase is utilized to metabolize pyruvate.

  13. Anaerobic treatment of wastewater containing methanol in upflow anaerobic sludge bed (UASB) reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The direct conversion of methanol into methane is the main process in anaerobic treatment of methanol containing wastewater.However,acetic acid can also be produced from methanol theoretically,which may probably result in an abrupt pH drop and deteriorate the anaerobic process.Therefore,it is interesting to know what would really happen in an anaerobic reactor treating methanol wastewater.In this study,an up-flow anaerobic sludge bed (UASB) reactor treating methanol wastewater was operated.The chemical oxygen demand (COD),acetic acid and pH of the effluent were monitored at different loadings and influent alkalinity.The results showed that the anaerobic reactor could be operated steadily at as low as 119 mg/L of influent alkalinity and high organic loading rate with no obvious pH drops.Volatile fatty acids accumulation was not observed even at strong shock loadings.The microorganisms in the sludge at the end of the test became homogeneous in morphology,which were mainly spherical or spheroidal in shape.

  14. Bacterial respiration of arsenic and selenium

    Science.gov (United States)

    Stolz, J.F.; Oremland, R.S.

    1999-01-01

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichment culture suggest that they are widespread and metabolically active in nature. Although the bacterial species that have been isolated and characterized are still few in number, they are scattered throughout the bacterial domain and include Gram- positive bacteria, beta, gamma and epsilon Proteobacteria and the sole member of a deeply branching lineage of the bacteria, Chrysiogenes arsenatus. The oxidation of a number of organic substrates (i.e. acetate, lactate, pyruvate, glycerol, ethanol) or hydrogen can be coupled to the reduction of arsenate and selenate, but the actual donor used varies from species to species. Both periplasmic and membrane-associated arsenate and selenate reductases have been characterized. Although the number of subunits and molecular masses differs, they all contain molybdenum. The extent of the environmental impact on the transformation and mobilization of arsenic and selenium by microbial dissimilatory processes is only now being fully appreciated.

  15. STUDY ON THE DECHLORINTION MECHANISMS DURING ANAEROBIC TREATMENT OF PULP BLEACHERY EFFLUENTS

    Institute of Scientific and Technical Information of China (English)

    Yuancai Chen; Xiuqiong Guan; Huaiyu Zhan; Zhonghao Chen; Shiyu Fu

    2004-01-01

    Anaerobic treatment could effectively degrade organic chlorine. Reductive dechlorination mechanisms were confirmed through GC-MS analysis during anaerobic treatment of pulp bleachery effluents, the influence of sulfide biologically produced and pH on the dechlorination revealed that nucleophilic substitution and alkaline hydrolysis were also nonbiological mechanisms.

  16. Effect of respiration and manganese on oxidative stress resistance of Lactobacillus plantarum WCFS1

    NARCIS (Netherlands)

    Watanabe, M.; Veen, van der S.; Nakajima, H.; Abee, T.

    2012-01-01

    Lactobacillus plantarum is a facultatively anaerobic bacterium that can perform respiration under aerobic conditions in the presence of haem, with vitamin K2 acting as a source of menaquinone. We investigated growth performance and oxidative stress resistance of Lb. plantarum WCFS1 cultures grown in

  17. Soil respiration in different agricultural and natural ecosystems in an arid region.

    Directory of Open Access Journals (Sweden)

    Liming Lai

    Full Text Available The variation of different ecosystems on the terrestrial carbon balance is predicted to be large. We investigated a typical arid region with widespread saline/alkaline soils, and evaluated soil respiration of different agricultural and natural ecosystems. Soil respiration for five ecosystems together with soil temperature, soil moisture, soil pH, soil electric conductivity and soil organic carbon content were investigated in the field. Comparing with the natural ecosystems, the mean seasonal soil respiration rates of the agricultural ecosystems were 96%-386% higher and agricultural ecosystems exhibited lower CO(2 absorption by the saline/alkaline soil. Soil temperature and moisture together explained 48%, 86%, 84%, 54% and 54% of the seasonal variations of soil respiration in the five ecosystems, respectively. There was a significant negative relationship between soil respiration and soil electrical conductivity, but a weak correlation between soil respiration and soil pH or soil organic carbon content. Our results showed that soil CO(2 emissions were significantly different among different agricultural and natural ecosystems, although we caution that this was an observational, not manipulative, study. Temperature at the soil surface and electric conductivity were the main driving factors of soil respiration across the five ecosystems. Care should be taken when converting native vegetation into cropland from the point of view of greenhouse gas emissions.

  18. Respiration in ocean margin sediments

    OpenAIRE

    Andersson, J.H.

    2007-01-01

    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data. In this thesis the depth dependence of respiration patterns was modelled using a compiled data set of sediment oxygen consumption rates. We showed that the depth relationship can best be described by a do...

  19. A study of photosynthetic biogas upgrading based on a high rate algal pond under alkaline conditions: Influence of the illumination regime.

    Science.gov (United States)

    Franco-Morgado, Mariana; Alcántara, Cynthia; Noyola, Adalberto; Muñoz, Raúl; González-Sánchez, Armando

    2017-03-20

    Microalgal-bacterial processes have emerged as environmental friendly systems for the cost-effective treatment of anaerobic effluents such as biogas and nutrients-laden digestates. Environmental parameters such as temperature, irradiation, nutrient concentration and pH effect the performance of the systems. In this paper, the potential of a microalgal-bacterial photobioreactor operated under high pH (≈9.5) and high alkalinity to convert biogas into biomethane was evaluated. The influence of the illumination regime (continuous light supply vs 12h/12h light/dark cycles) on the synthetic biogas upgrading efficiency, biomass productivity and nutrient removal efficiency was assessed in a High-Rate Algal Pond interconnected to a biogas absorption bubble column. No significant differences in the removal efficiency of CO2 and H2S (91.5±2% and 99.5%±0.5, respectively) were recorded regardless of the illumination regime. The high fluctuations of the dissolved oxygen concentration during operation under light/dark cycles allowed to evaluate the specific growth rate and the specific partial degradation rate of the microalgae biomass by photosynthesis and respiration, respectively. The respiration reduced the net microalgae biomass productivity under light/dark cycles compared with process operation under the continuous light supply.

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

    Science.gov (United States)

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

    2009-03-01

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

  1. Anaerobic Digestion Analysis. Training Module 5.120.2.77.

    Science.gov (United States)

    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…

  2. Anodes for alkaline electrolysis

    Science.gov (United States)

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  3. Anaerobic Digestion: Process

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Batstone, Damien J.

    2011-01-01

    with very little dry matter may also be called a digest. The digest should not be termed compost unless it specifically has been composted in an aerated step. This chapter describes the basic processes of anaerobic digestion. Chapter 9.5 describes the anaerobic treatment technologies, and Chapter 9.......6 addresses the mass balances and environmental aspects of anaerobic digestion....

  4. Light respiration in Chlorella sorokiniana

    NARCIS (Netherlands)

    Kliphuis, A.M.J.; Janssen, M.G.J.; End, van den E.J.; Martens, D.E.; Wijffels, R.H.

    2011-01-01

    Respiration and photosynthesis are two important processes in microalgal growth that occur simultaneously in the light. To know the rates of both processes, at least one of them has to be measured. To be able to measure the rate of light respiration of Chlorella sorokiniana, the measurement of oxyge

  5. Alkaline battery operational methodology

    Science.gov (United States)

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  6. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  7. From breathing to respiration.

    Science.gov (United States)

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  8. Benefit of sodium hydroxide pretreatment of ensiled sorghum forage on the anaerobic reactor stability and methane production.

    Science.gov (United States)

    Sambusiti, C; Ficara, E; Malpei, F; Steyer, J P; Carrère, H

    2013-09-01

    The assessment of the pretreatment effect on the anaerobic digestion process is generally based on the results of batch tests, which may fail in truly predicting full-scale anaerobic reactors performance. Therefore, in this study, the effect of alkaline pretreatment on the anaerobic digestion of ensiled sorghum forage was evaluated by comparing the results of two semi-continuous CSTR (Continuously Stirred Tank Reactor) anaerobic reactors. Results showed that an alkaline pretreatment step, prior to the anaerobic digestion of ensiled sorghum forage, can have a beneficial effect both in enhancing methane production (an increase of 25% on methane production was observed, if compared to that of untreated sorghum) and in giving more stability to the anaerobic digestion process.

  9. Oxygen regulated gene expression in facultatively anaerobic bacteria.

    Science.gov (United States)

    Unden, G; Becker, S; Bongaerts, J; Schirawski, J; Six, S

    1994-01-01

    In facultatively anaerobic bacteria such as Escherichia coli, oxygen and other electron acceptors fundamentally influence catabolic and anabolic pathways. E. coli is able to grow aerobically by respiration and in the absence of O2 by anaerobic respiration with nitrate, nitrite, fumarate, dimethylsulfoxide and trimethylamine N-oxide as acceptors or by fermentation. The expression of the various catabolic pathways occurs according to a hierarchy with 3 or 4 levels. Aerobic respiration at the highest level is followed by nitrate respiration (level 2), anaerobic respiration with the other acceptors (level 3) and fermentation. In other bacteria, different regulatory cascades with other underlying principles can be observed. Regulation of anabolism in response to O2 availability is important, too. It is caused by different requirements of cofactors or coenzymes in aerobic and anaerobic metabolism and by the requirement for different O2-independent biosynthetic routes under anoxia. The regulation mainly occurs at the transcriptional level. In E. coli, 4 global regulatory systems are known to be essential for the aerobic/anaerobic switch and the described hierarchy. A two-component sensor/regulator system comprising ArcB (sensor) and ArcA (transcriptional regulator) is responsible for regulation of aerobic metabolism. The FNR protein is a transcriptional sensor-regulator protein which regulates anaerobic respiratory genes in response to O2 availability. The gene activator FhlA regulates fermentative formate and hydrogen metabolism with formate as the inductor. ArcA/B and FNR directly respond to O2, FhlA indirectly by decreased levels of formate in the presence of O2. Regulation of nitrate/nitrite catabolism is effected by two 2-component sensor/regulator systems NarX(Q)/NarL(P) in response to nitrate/nitrite. Co-operation of the different regulatory systems at the target promoters which are in part under dual (or manifold) transcriptional control causes the expression

  10. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones.

    Science.gov (United States)

    Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M; Revsbech, Niels Peter; Löscher, Carolin; Schunck, Harald; Desai, Dhwani K; Hauss, Helena; Kiko, Rainer; Holtappels, Moritz; LaRoche, Julie; Schmitz, Ruth A; Graco, Michelle I; Kuypers, Marcel M M

    2015-01-01

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

  11. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones.

    Directory of Open Access Journals (Sweden)

    Tim Kalvelage

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

  12. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;

    2003-01-01

    measurements are reviewed in detail. In the sequel, possible manipulated variables, such as the hydraulic retention time, the organic loading rate, the sludge retention time, temperature, pH and alkalinity are evaluated with respect to the two main reactor types: high-rate and low-rate. Finally, the different......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  13. Identification of electrode respiring, hydrocarbonoclastic bacterial strain Stenotrophomonas maltophilia MK2 highlights the untapped potential for environmental bioremediation

    OpenAIRE

    2016-01-01

    Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential towards organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon f...

  14. Alkaline earth metal thioindates

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov-Ehmin, B.N.; Ivlieva, V.I.; Filatenko, L.A.; Zajtsev, B.E.; Kaziev, G.Z.; Sarabiya, M.G.

    1984-08-01

    Alkaline earth metal thioindates of MIn/sub 2/S/sub 4/ composition were synthesized by interaction of alkaline earth metal oxoindates with hydrogen sulfide during heating. Investigation into the compounds by X-ray analysis showed that calcium compound crystallizes in cubic crystal system and strontium and barium compounds in rhombic crystal system. Lattice parameters and the number of formula units were determined. Thioindates of M/sub 3/In/sub 2/S/sub 6/ composition were synthesized, their individuality was shown.

  15. Anaerobic alkaline digestion of sewage sludge. 4. ed. Anaerobe alkalische Schlammfaulung

    Energy Technology Data Exchange (ETDEWEB)

    Roediger, H.; Roediger, M.; Kapp, H.

    1990-01-01

    The book presents a historical outline, the biological and chemical processes, measures for intensivation and disinfestation, and for dimensioning and installation of sewage sludge digestion systems. (EF).

  16. Life in the absence of oxygen: alterative electron acceptors for anaerobic microorganisms in a petroleum environment

    NARCIS (Netherlands)

    Balk, M.

    2007-01-01

    Anaerobic microorganisms derive energy by transferring electrons from an external source or donor to an external electron sink or terminal acceptor and often have the capacity to reduce 2 or more terminal electron acceptors. The well-known type of microbial respiration, in which oxygen serves as an

  17. Contribution of anaerobic energy expenditure to whole body thermogenesis

    Directory of Open Access Journals (Sweden)

    Scott Christopher B

    2005-06-01

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

  18. Anaerobic Digestion and its Applications

    Science.gov (United States)

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

  19. Early warning indicators for monitoring the process failure of anaerobic digestion system of food waste.

    Science.gov (United States)

    Li, Lei; He, Qingming; Wei, Yunmei; He, Qin; Peng, Xuya

    2014-11-01

    To determine reliable state parameters which could be used as early warning indicators of process failure due to the acidification of anaerobic digestion of food waste, three mesophilic anaerobic digesters of food waste with different operation conditions were investigated. Such parameters as gas production, methane content, pH, concentrations of volatile fatty acid (VFA), alkalinity and their combined indicators were evaluated. Results revealed that operation conditions significantly affect the responses of parameters and thus the optimal early warning indicators of each reactor differ from each other. None of the single indicators was universally valid for all the systems. The universally valid indicators should combine several parameters to supply complementary information. A combination of total VFA, the ratio of VFA to total alkalinity (VFA/TA) and the ratio of bicarbonate alkalinity to total alkalinity (BA/TA) can reflect the metabolism of the digesting system and realize rapid and effective early warning.

  20. Use of Facemasks and Respirators

    Centers for Disease Control (CDC) Podcasts

    2007-05-15

    This program demonstrates the differences of facemasks and respirators that are to be used in public settings during an influenza pandemic.  Created: 5/15/2007 by CDC, National Institute for Occupational Safety and Health (NIOSH).   Date Released: 5/25/2007.

  1. General Instructions for Disposable Respirators

    Centers for Disease Control (CDC) Podcasts

    2009-04-09

    This podcast, intended for the general public, demonstrates how to put on and take off disposable respirators that are to be used in areas affected by the influenza outbreak.  Created: 4/9/2009 by CDC, National Institute for Occupational Safety and Health (NIOSH).   Date Released: 4/29/2009.

  2. Increased performance of hydrogen production in microbial electrolysis cells under alkaline conditions.

    Science.gov (United States)

    Rago, Laura; Baeza, Juan A; Guisasola, Albert

    2016-06-01

    This work reports the first successful enrichment and operation of alkaline bioelectrochemical systems (microbial fuel cells, MFC, and microbial electrolysis cells, MEC). Alkaline (pH=9.3) bioelectrochemical hydrogen production presented better performance (+117%) compared to conventional neutral conditions (2.6 vs 1.2 litres of hydrogen gas per litre of reactor per day, LH2·L(-1)REACTOR·d(-1)). Pyrosequencing results of the anodic biofilm showed that while Geobacter was mainly detected under conventional neutral conditions, Geoalkalibacter sp. was highly detected in the alkaline MFC (21%) and MEC (48%). This is the first report of a high enrichment of Geoalkalibacter from an anaerobic mixed culture using alkaline conditions in an MEC. Moreover, Alkalibacter sp. was highly present in the anodic biofilm of the alkaline MFC (37%), which would indicate its potentiality as a new exoelectrogen.

  3. Soil Respiration: Concept and Measurement Methods

    Directory of Open Access Journals (Sweden)

    SANDOR M.

    2010-08-01

    Full Text Available Soil respiration is the main element in the carbon cycle that makes possible for plants carbon plants to return inthe atmosphere. The objective of this work was to present and discuss some aspects of the soil CO2 efflux. We definedherein, some terms associated to the soil respiration concept, we tackled some aspects regarding the influence oftemperature, humidity and soil pH on soil respiration and we presented the principle of soil respiration measurement byusing dynamic closed chamber system.

  4. Alkaline broadening in Stars

    CERN Document Server

    De Kertanguy, A

    2015-01-01

    Giving new insight for line broadening theory for atoms with more structure than hydrogen in most stars. Using symbolic software to build precise wave functions corrected for ds;dp quantum defects. The profiles obtained with that approach, have peculiar trends, narrower than hydrogen, all quantum defects used are taken from atomic database topbase. Illustration of stronger effects of ions and electrons on the alkaline profiles, than neutral-neutral collision mechanism. Keywords : Stars: fundamental parameters - Atomic processes - Line: profiles.

  5. Anaerobic digestion of yard waste with hydrothermal pretreatment.

    Science.gov (United States)

    Li, Wangliang; Zhang, Guangyi; Zhang, Zhikai; Xu, Guangwen

    2014-03-01

    The digestibility of lignocellulosic biomass is limited by its high content of refractory components. The objective of this study is to investigate hydrothermal pretreatment and its effects on anaerobic digestion of sorted organic waste with submerged fermentation. Hydrothermal pretreatment (HT) was performed prior to anaerobic digestion, and three agents were examined for the HT: hot compressed water, alkaline solution, and acidic solution. The concentrations of glucose and xylose were the highest in the sample pretreated in acidic solution. Compared with that of the untreated sample, the biogas yields from digesting the samples pretreated in alkaline solution, acidic solution, and hot water increased by 364, 107, and 79%, respectively. The decrease of chemical oxygen demand (COD) in liquid phase followed the same order as for the biogas yield. The initial ammonia content of the treated samples followed the order sample treated in acidic solution > sample treated in alkaline solution > sample treated in hot water. The concentrations of volatile fatty acids (VFAs) were low, indicating that the anaerobic digestion process was running at continuously stable conditions.

  6. Anaerobic Digestion Foaming Causes

    OpenAIRE

    Ganidi, Nafsika

    2008-01-01

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

  7. The Midbrain Periaqueductal Gray Control of Respiration

    NARCIS (Netherlands)

    Subramanian, Hari H.; Balnave, Ron J.; Holstege, Gert

    2008-01-01

    The midbrain periaqueductal gray (PAG) organizes basic survival behavior, which includes respiration. How the PAG controls respiration is not known. We studied the PAG control of respiration by injecting D,L-homocysteic acid in the PAG in unanesthetized precollicularly decerebrated cats. Injections

  8. 30 CFR 57.5044 - Respirators.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirators. 57.5044 Section 57.5044 Mineral... Agents, and Diesel Particulate Matter Radiation-Underground Only § 57.5044 Respirators. In environments exceeding 1.0 WL, miners shall wear respirators approved by NIOSH for radon daughters prior to July 10,...

  9. [Effects of simulated acid rain on respiration rate of cropland system with different soil pH].

    Science.gov (United States)

    Zhu, Xue-zhu; Zhang, Gao-chuan; Li, Hui

    2009-10-15

    To evaluate the effects of acid rain on the respiration rate of cropland system, an outdoor pot experiment was conducted with paddy soils of pH 5.48 (S1), pH 6.70 (S1) and pH 8.18 (S3) during the 2005-2007 wheat-growing seasons. The cropland system was exposed to acid rain by spraying the wheat foliage and irrigating the soil with simulated rainwater of T1 (pH 6.0), T2 (pH 6.0, ionic concentration was twice as rainwater T1), and T3 (pH 4.4, ionic concentration was twice as rainwater T1), respectively. The static opaque chamber-gas chromatograph method was used to measure CO2 fluxes from cropland system. The results showed that acid rain affected the respiration rate of cropland system through crop plant, and the cropland system could adapt to acid rain. Acid rainwater significantly increased the average respiration rate in alkaline soil (S3) cropland system, while it had no significant effects on the average respiration rate in neutral soil (S2) and acidic soil (S1) cropland systems. During 2005-2006, after the alkaline soil cropland system was treated with rainwater T3, the average respiration rate was 23.6% and 27.6% higher than that of alkaline soil cropland system treated with rainwater T1 and T2, respectively. During March to April, the respiration rate was enhanced with the increase of rainwater ionic concentration, while it was dropped with the decrease of rainwater pH value in acidic soil cropland system. It was demonstrated that soil pH and crop plant played important roles on the respiration rate of cropland system.

  10. Plastron Respiration Using Commercial Fabrics

    OpenAIRE

    2014-01-01

    A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer...

  11. Anaerobic Biodegradation of Detergent Surfactants

    Directory of Open Access Journals (Sweden)

    Erich Jelen

    2009-03-01

    Full Text Available Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants.

  12. Comparison of liquid hot water and alkaline pretreatments of giant reed for improved enzymatic digestibility and biogas energy production.

    Science.gov (United States)

    Jiang, Danping; Ge, Xumeng; Zhang, Quanguo; Li, Yebo

    2016-09-01

    Liquid hot water (LHW) and alkaline pretreatments of giant reed biomass were compared in terms of digestibility, methane production, and cost-benefit efficiency for electricity generation via anaerobic digestion with a combined heat and power system. Compared to LHW pretreatment, alkaline pretreatment retained more of the dry matter in giant reed biomass solids due to less severe conditions. Under their optimal conditions, LHW pretreatment (190°C, 15min) and alkaline pretreatment (20g/L of NaOH, 24h) improved glucose yield from giant reed by more than 2-fold, while only the alkaline pretreatment significantly (pAlkaline pretreatment achieved 27% higher net electrical energy production than that of non-pretreatment (3859kJ/kg initial total solids), but alkaline liquor reuse is needed for improved net benefit.

  13. Life at extreme limits: the anaerobic halophilic alkalithermophiles.

    Science.gov (United States)

    Mesbah, Noha M; Wiegel, Juergen

    2008-03-01

    The ability of anaerobic microorganisms to proliferate under extreme conditions is of widespread importance for microbial physiology, remediation, industry, and evolution. The halophilic alkalithermophiles are a novel group of polyextremophiles. Tolerance to alkaline pH, elevated NaCl concentrations, and high temperatures necessitates mechanisms for cytoplasmic pH acidification; permeability control of the cell membrane; and stability of proteins, the cell wall, and other cellular constituents to multiple extreme conditions. Although it is generally assumed that extremophiles growing at more than one extreme combine adaptive mechanisms for each individual extreme, adaptations for individual extremes often counteract each other. However, in alkaline, hypersaline niches heated via intense solar irradiation, culture-independent analyses have revealed the presence of an extensive diversity of aerobic and anaerobic microorganisms belonging to Bacteria and Archaea that survive and grow under multiple harsh conditions. Thus, polyextremophiles must have developed novel adaptive strategies enabling them to grow and proliferate under multiple extreme conditions. The recent isolation of two novel anaerobic, halophilic alkalithermophiles, Natranaerobius thermophilus and Halonatronum saccharophilum, will provide a platform for detailed biochemical, genomic, and proteomic experiments, allowing a greater understanding of the novel adaptive mechanisms undoubtedly employed by polyextremophiles. In this review, we highlight growth characteristics, ecology, and phylogeny of the anaerobic halophilic alkalithermophiles isolated. We also describe the bioenergetic and physiological problems posed by growth at the multiple extreme conditions of alkaline pH, high NaCl concentration, and elevated temperature under anoxic conditions and highlight recent findings and unresolved problems regarding adaptation to multiple extreme conditions.

  14. Enhancing anaerobic digestion of waste activated sludge by pretreatment: effect of volatile to total solids.

    Science.gov (United States)

    Wang, Xiao; Duan, Xu; Chen, Jianguang; Fang, Kuo; Feng, Leiyu; Yan, Yuanyuan; Zhou, Qi

    2016-01-01

    In this study the effect of volatile to total solids (VS/TS) on anaerobic digestion of waste activated sludge (WAS) pretreated by alkaline, thermal and thermal-alkaline strategies was studied. Experimental results showed that the production of methane from sludge was increased with VS/TS. When anaerobic digesters were fed with sludge pretreated by the thermal-alkaline method, the average methane yield was improved from 2.8 L/d at VS/TS 0.35 to 4.7 L/d at VS/TS 0.56. Also, the efficiency of VS reduction during sludge anaerobic digestion varied between 18.9% and 45.6%, and increased gradually with VS/TS. Mechanism investigation of VS/TS on WAS anaerobic digestion suggested that the general activities of anaerobic microorganisms, activities of key enzymes related to sludge hydrolysis, acidification and methanogenesis, and the ratio of Archaea to Bacteria were all increased with VS/TS, showing good agreement with methane production.

  15. Anaerobic bacteria in otitis media.

    Science.gov (United States)

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

    1977-01-01

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

  16. An alkaline element

    Energy Technology Data Exchange (ETDEWEB)

    Arita, T.; Murakami, K.; Okha, K.

    1983-04-28

    A cathode with a dual layer active mass is installed in the disk shaped alkaline silver and zinc element. The first layer, which is turned towards the anode, contains 85 parts Ag2O, 5 parts electrolytic MnO2 and 10 parts graphite. The second layer, which contacts the bottom of the element, contains 35 parts Ag2O, 60 parts electrolytic MnO2 and 5 parts graphite. The electrical capacity of the first and second layers is 60 and 40, respectively. The first layer may be discharged with a high current density and the second layer with less current density. The element has high characteristics with comparatively low cost.

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

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  18. Respirators: Supervisors Self-Study #43442

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    This course, Respirators: Supervisors Self-Study (#43442), addresses training requirements for supervisors of respirator wearers as specified by the American National Standard Institute (ANSI) Standard for Respiratory Protection, ANSI Z88.2, and as incorporated by reference in the Department of Energy (DOE) Worker Health and Safety Rule, 10 Code of Federal Regulations (CFR) 851. This course also presents the responsibilities of supervisors of respirator wearers at Los Alamos National Laboratory (LANL).

  19. The anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-01-01

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

  20. Anaerobic digestion without biogas?

    NARCIS (Netherlands)

    Kleerebezem, R.; Joosse, B.; Rozendaal, R.; Van Loosdrecht, M.C.M.

    2015-01-01

    Anaerobic digestion for the production of methane containing biogas is the classic example of a resource recovery process that combines stabilization of particulate organic matter or wastewater treatment with the production of a valuable end-product. Attractive features of the process include the pr

  1. Plastron Respiration Using Commercial Fabrics

    Directory of Open Access Journals (Sweden)

    Shaun Atherton

    2014-01-01

    Full Text Available A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer membranes is investigated, and how the surface of the materials mimics this mechanism of underwater respiration is demonstrated allowing direct extraction of oxygen from oxygenated water. The coverage of the surface with the plastron air layer was measured using confocal microscopy. A zinc/oxygen cell is used to consume oxygen within containers constructed from the different membranes, and the oxygen consumed by the cell is compared to the change in oxygen concentration as measured by an oxygen probe. By comparing the membranes to an air-tight reference sample, it was found that the membranes facilitated oxygen transfer from the water into the container, with the most successful membrane showing a 1.90:1 ratio between the cell oxygen consumption and the change in concentration within the container.

  2. Characteristics of high-sulfate wastewater treatment by two-phase anaerobic digestion process with Jet-loop anaerobic fluidized bed

    Institute of Scientific and Technical Information of China (English)

    WEI Chao-hai; WANG Wen-xiang; DENG Zhi-yi; WU Chao-fei

    2007-01-01

    A new anaerobic reactor,Jet-loop anaerobic fluidized bed(JLAFB),was designed for treating high-sulfate wastewater.The treatment characteristics,including the effect of influent COD/SO42- ratio and alkalinity and sulfide inhibition in reactors,were discussed for a JLAFB and a general anaerobic fluidized bed(AFB)reactor used as sulfate-reducing phase and methane-producing phase,respectively,in two-phase anaerobic digestion process.The formation of granules in the two reactors was also examined.The results indicated that COD and sulfate removal had different demand of influent COD/S042- ratios.When total COD removal Was up to 85%,the ratio was only required up to 1.2,whereas,total sulfate removal up to 95%required it exceeding 3.0.The alkalinity in the two reactors increased linearly with the growth of influent alkalinity.Moreover,the change of influent alkalinity had no significant effect on pH and volatile fatty acids(VFA)in the two reactors.Influent alkalinity kept at 400-500 mg/t,could meet the requirement of the treating process.The JLAFB reactor had great advantage in avoiding sulfide and free-H2S accumulation and toxicity inhibition on microorganisms.When sulfate loading rate was up to 8.1 kg/(m3·d),the sulfide and free-H2S concentrations in JLAFB reactor were 58.6 and 49.7 mg/L,respectively.Furthermore,the granules,with offwhite color,ellipse shape and diameters of 1.0-3.0 mm,could be developed in JLAFB reactor.In granules,different groups of bacteria were distributed in different layers,and some inorganic metal compounds such as Fe,Ca,Mg etc.were found.

  3. 42 CFR 84.197 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.197... Cartridge Respirators § 84.197 Respirator containers; minimum requirements. Respirators shall be equipped... commercial designation of the respirator it contains and all appropriate approval labels....

  4. 42 CFR 84.134 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.134... Respirators § 84.134 Respirator containers; minimum requirements. Supplied-air respirators shall be equipped... commercial designation of the respirator it contains, and all appropriate approval labels....

  5. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical cartridge respirators: description. 84.190... Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical cartridge respirators including all completely assembled respirators which are designed for use as...

  6. 42 CFR 84.130 - Supplied-air respirators; description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Supplied-air respirators; description. 84.130... Respirators § 84.130 Supplied-air respirators; description. Supplied-air respirators, including all completely assembled respirators designed for use as respiratory protection during entry into and escape...

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

    Science.gov (United States)

    Bannert, A.; Bogen, C.; Esperschütz, J.; Koubová, A.; Buegger, F.; Fischer, D.; Radl, V.; Fuß, R.; Chroňáková, A.; Elhottová, D.; Šimek, M.; Schloter, M.

    2012-10-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Bannert

    2012-04-01

    Full Text Available While the importance of anaerobic methane oxidation has been reported for marine ecosystems, the role of this process in soils is still questionable. Grasslands used as pastures for cattle-overwintering show an increase in anaerobic soil micro-sites caused by animal treading and excrement deposition. Therefore anaerobic potential methane oxidation activity of severely impacted soil from a cattle winter pasture was investigated in an incubation experiment under anaerobic conditions using 13C-labeled methane. We were able to detect a high microbial activity utilizing CH4 as nutrient source shown by the respiration of 13CO2. Measurements of possible terminal electron acceptors for anaerobic oxidation of methane were carried out. Soil sulfate concentrations were too low to explain the oxidation of the amount of methane added, but enough nitrate and iron(III were detected. However, only nitrate was consumed during the experiment. 13C-PLFA analyses clearly showed the utilization of CH4 as nutrient source mainly by organisms harbouring 16:1ω7 PLFAs. These lipids were found in Gram-negative microorganisms and anaerobes. The fact that these lipids are also typical for type I methanotrophs, known as aerobic methane oxidizers, might indicate a link between aerobic and anaerobic methane oxidation.

  9. Digestibility Improvement of Sorted Waste with Alkaline Hydrothermai Pretreatment

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; WANG Hongtao; LU Wenjing; ZHAO Yan

    2009-01-01

    The digestibility of sorted municipal solid waste (MSW) is often limited by the high content of structured green waste. The objectives of this study are to investigate the effect of alkaline hydrothermal pretreatment on the anaerobic digestion of sorted waste and to analyze the biogas production of different parts of the waste. The waste was hydrothermally pretreated in a dilute alkali solution. The hydrolysis product was then incubated in a 500 mL saline bottle to determine the biochemical methane potential (BMP) under mesophilic anaerobic conditions. The optimum hydrothermal condition was 170℃ at 4 g NaOH/100 g solid for one hour. The concentration of chemical oxygen demand (COD) was 13 936 mg/L and the methane yield was 164 mL/g volatile solid (VS) for 6 days incubation at the optimum conditions. The biogas production was increased more than 50% over the control, with the methane conversion ratio on a carbon basis enhanced to 30.6%. The organic part of the sorted waste was mainly kitchen garbage and leaves. Model kitchen garbage completely liquified at 130℃ for one hour had a methane yield of 276 mL/g VS. The alkali addition slightly enhanced the hydrolyzation rate and methane yield. The biogas potential of leaves was improved by pre-treatment at above 150℃ under alkaline conditions.

  10. Mitochondrial respiration is sensitive to cytoarchitectural breakdown.

    Science.gov (United States)

    Kandel, Judith; Angelin, Alessia A; Wallace, Douglas C; Eckmann, David M

    2016-11-07

    An abundance of research suggests that cellular mitochondrial and cytoskeletal disruption are related, but few studies have directly investigated causative connections between the two. We previously demonstrated that inhibiting microtubule and microfilament polymerization affects mitochondrial motility on the whole-cell level in fibroblasts. Since mitochondrial motility can be indicative of mitochondrial function, we now further characterize the effects of these cytoskeletal inhibitors on mitochondrial potential, morphology and respiration. We found that although they did not reduce mitochondrial inner membrane potential, cytoskeletal toxins induced significant decreases in basal mitochondrial respiration. In some cases, basal respiration was only affected after cells were pretreated with the calcium ionophore A23187 in order to stress mitochondrial function. In most cases, mitochondrial morphology remained unaffected, but extreme microfilament depolymerization or combined intermediate doses of microtubule and microfilament toxins resulted in decreased mitochondrial lengths. Interestingly, these two particular exposures did not affect mitochondrial respiration in cells not sensitized with A23187, indicating an interplay between mitochondrial morphology and respiration. In all cases, inducing maximal respiration diminished differences between control and experimental groups, suggesting that reduced basal respiration originates as a largely elective rather than pathological symptom of cytoskeletal impairment. However, viability experiments suggest that even this type of respiration decrease may be associated with cell death.

  11. Respirators: APR Issuer Self Study 33461

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Laboratory

    2016-07-13

    Respirators: APR Issuer Self-Study (course 33461) is designed to introduce and familiarize employees selected as air-purifying respirator (APR) issuers at Los Alamos National Laboratory (LANL) with the responsibilities, limitations, procedures, and resources for issuing APRs at LANL. The goal is to enable these issuers to consistently provide proper, functioning APRs to authorized users

  12. 78 FR 18535 - Respirator Certification Fees

    Science.gov (United States)

    2013-03-27

    ....\\4\\ A summary of market segmentation, by respirator type, is offered in Table 1, below. \\4\\ Frost... be determined on a case-by-case basis; considerations will include an assessment of the manufacturer... and paint applications and hazardous materials management. Of the U.S. respirator market of...

  13. The effects of operational and environmental variations on anaerobic wastewater treatment systems: a review

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R.C. [Embrapa Agroindustria Tropical (Brazilian Agricultural Research Corporation, Inst. of Tropical Agroindustry), Fortaleza (Brazil); Haandel, A.C. van [Federal University of Campina Grande (Brazil); Zeeman, G.; Lettinga, G. [Wageningen Univ. (Netherlands)

    2006-06-15

    With the aim of improving knowledge about the stability and reliability of anaerobic wastewater treatment systems, several researchers have studied the effects of operational or environmental variations on the performance of such reactors. In general, anaerobic reactors are affected by changes in external factors, but the severity of the effect is dependent upon the type, magnitude, duration and frequency of the imposed changes. The typical responses include a decrease in performance, accumulation of volatile fatty acids, drop in pH and alkalinity, change in biogas production and composition, and sludge washout. This review summarises the causes, types and effects of operational and environmental variation on anaerobic wastewater treatment systems. However, there still remain some unclear technical and scientific aspects that are necessary for the improvement of the stability and reliability of anaerobic processes. (author)

  14. Contribution of root respiration to soil respiration in a C3/C4 mixed grassland

    Indian Academy of Sciences (India)

    Wei Wang; Kenji Ohse; Jianjun Liu; Wenhong Mo; Takehisa Oikawa

    2005-09-01

    The spatial and temporal variations of soil respiration were studied from May 2004 to June 2005 in a C3/C4 mixed grassland of Japan. The linear regression relationship between soil respiration and root biomass was used to determine the contribution of root respiration to soil respiration. The highest soil respiration rate of 11.54 mol m–2 s–1 was found in August 2004 and the lowest soil respiration rate of 4.99 mol m–2 s–1 was found in April 2005. Within-site variation was smaller than seasonal change in soil respiration. Root biomass varied from 0.71 kg m–2 in August 2004 to 1.02 in May 2005. Within-site variation in root biomass was larger than seasonal variation. Root respiration rate was highest in August 2004 (5.7 mol m–2 s–1) and lowest in October 2004 (1.7 mol m–2 s–1). Microbial respiration rate was highest in August 2004 (5.8 mol m–2 s–1) and lowest in April 2005 (2.59 mol m–2 s–1). We estimated that the contribution of root respiration to soil respiration ranged from 31% in October to 51% in August of 2004, and from 45% to 49% from April to June 2005.

  15. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

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

    2001-01-01

    The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern...... requirements. In fact, most advances were achieved during the last three decades, when high-rate reactor systems were developed and a profound insight was obtained in the microbiology of the anaerobic communities. This insight led to a better understanding of anaerobic treatment and, subsequently, to a broader...

  16. Anaerobic digestion of recalcitrant textile dyeing sludge with alternative pretreatment strategies.

    Science.gov (United States)

    Xiang, Xinyi; Chen, Xiaoguang; Dai, Ruobin; Luo, Ying; Ma, Puyue; Ni, Shengsheng; Ma, Chengyu

    2016-12-01

    Abundant organic compounds in textile dyeing sludge (TDS) provide possibility for its anaerobic digestion (AD) treatment. However, preliminary test showed little biogas generation in direct AD of the TDS during 20days. In order to improve the AD availability of TDS, alkaline, acid, thermal and thermal alkaline pretreatments were performed. Color and aromatic amines were specifically measured as extra characteristics for the AD of TDS. The rate-limiting steps of AD of TDS were slow hydrolysis rate and inhibited acidogenesis, which were somewhat overcome by pretreatments. Thermal alkaline pretreated TDS performed best enhancement on solubilisation. The biochemical methane potential tests revealed that thermal pretreated TDS showed highest total methane production of 55.9mL/gVSfed compared to the control with little methane generation. However, thermal alkaline pretreated TDS did not perform well in BMP test as expected. Moreover, the hydrophilicity of reactive dyes in TDS could seriously affect dewaterability of TDS.

  17. Aerobic respiration in the Archaean?

    Science.gov (United States)

    Towe, K M

    1990-11-01

    The Earth's atmosphere during the Archaean era (3,800-2,500 Myr ago) is generally thought to have been anoxic, with the partial pressure of atmospheric oxygen about 10(-12) times the present value. In the absence of aerobic consumption of oxygen produced by photosynthesis in the ocean, the major sink for this oxygen would have been oxidation of dissolved Fe(II). Atmospheric oxygen would also be removed by the oxidation of biogenic methane. But even very low estimates of global primary productivity, obtained from the amounts of organic carbon preserved in Archaean rocks, seem to require the sedimentation of an unrealistically large amount of iron and the oxidation of too much methane if global anoxia was to be maintained. I therefore suggest that aerobic respiration must have developed early in the Archaean to prevent a build-up of atmospheric oxygen before the Proterozoic. An atmosphere that contained a low (0.2-0.4%) but stable proportion of oxygen is required.

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

    Science.gov (United States)

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

    2003-12-01

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

  19. Decolorization of azo dyes under batch anaerobic and sequential anaerobic/aerobic conditions.

    Science.gov (United States)

    Işik, Mustafa; Sponza, Delia Teresa

    2004-01-01

    Batch anaerobic and sequential anaerobic upflow anaerobic sludge blanket (UASB)/aerobic continuous stirred tank reactor (CSTR) were used to determine the color and COD removals under anaerobic/aerobic conditions. Two azo dyes namely "Reactive Black 5 (RB 5)," "Congo Red (CR)," and glucose as a carbon source were used for synthetic wastewater. The course of the decolorization process approximates to first order and zero order kinetics with respect to dye concentration for RB 5 and Congo Red azo dyes, respectively, in batch conditions. The decolorization kinetic constant (K0) values increased from 3.6 to 11.8 mg(L h)(-1) as increases in dye concentrations from 200 to 3200 mg L(-1) for CR. Increases in dye concentrations from 0 to 3200 mg L(-1) reduce the decolorization rate constant (k1) values from 0.0141 to 0.0019 h(-1) in batch studies performed with RB 5. Decolorization was achieved effectively under test conditions but ultimate decolorization of azo dyes was not observed at all dye concentrations in batch assay conditions. Dye concentrations of 100 mg L(-1) and 3000 mg L(-1) of glucose-COD containing basal medium were used for continuous studies. The effect of organic loadings and HRT, on the color removal efficiencies and methane gas productions were monitored. 94.1-45.4% COD and 79-73% color removal efficiencies were obtained at an organic system during decolorization of Reactive Black 5. 92.3-77.0% COD and 95.3-92.2% decolorization efficiencies were achieved at a organic loading rate of 1.03-6.65 kg (m3 day)(-1) and a HRT of 3.54-0.49 for Congo Red treatment. The results of this study showed that, although decolorization continued, COD removal efficiencies and methane gas production were depressed at high organic loadings under anaerobic conditions. Furthermore, VFA accumulation, alkalinity consumption, and methane gas percentage were monitored at organic loading as high as 2.49-4.74 kg (m3 day)(-1) and 24.60-30.62 kg (m3 day)(-1), respectively, through the

  20. Probing soil respiration process of grasslands

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Soil respiration, which is primarily the only output approach for CO2 exchanges in soils between the global terrestrial ecosystem and the atmosphere,exerts a direct influence on the speed of carbon turnover rate of the soil.

  1. Investigations on the inactivation of selected bacteria and viruses during mesophilic and thermophilic anaerobic alkaline cofermentation of biological waste materials, food residues and other animal residues; Seuchenhygienische Untersuchungen zur Inaktivierung ausgewaehlter Bakterien und Viren bei der mesophilen und thermophilen anaeroben alkalischen Faulung von Bio- und Kuechenabfaellen sowie anderen Rest- und Abfallstoffen tierischer Herkunft

    Energy Technology Data Exchange (ETDEWEB)

    Hoferer, M. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Umwelt- und Tierhygiene sowie Tiermedizin mit Tierklinik

    2001-07-01

    The purpose of this study is to investigate the inactivation kinetics of a number of different bacteria (Salmonella Senftenberg, Escherichia coli O157, Enterococcus faecium) and viruses (Bovine Enterovirus (ECBO), Equine Rhinovirus (ERV), Poliovirus, Bovine Parvovirus (BPV)) during the process of anaerobic cofermentation. Experiments were conducted in a semi-technical biogas plant at the University of Hohenheim. The fermenter was fed with a mixture of slurry from pigs or cattle (75%) and leftovers (25%) and was run under mesophilic (30 C + 35 C) as well as under thermophilic temperature conditions (50 C + 55 C). Volume and filter-sandwich germ-carriers were specifically developed and/or optimised for these analyses. Parallel to the experiments at the University of Hohenheim and under almost identical process conditions, various viruses (African Swine Fever Virus, Pseudorabies Virus, Classical Swine Fever Virus, Foot and Mouth Disease Virus, Swine Vesicular Disease Virus) were examined at the Federal Research Centre for Virus Diseases of Animals in Tuebingen. The results obtained at each research institution are directly compared. (orig.)

  2. Anaerobic Digestion of Piggery Waste

    NARCIS (Netherlands)

    Velsen, van A.F.M.

    1981-01-01

    Anaerobic digestion is a biological process by which organic matter is converted to methane and carbon dioxide by microbes in the absence of air (oxygen). In nature, anaerobic conversions occur at all places where organic material accumulates and the supply of oxygen is deficient, e.g. in marshes an

  3. Economic viability of anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Wellinger, A. [INFOENERGIE, Ettenhausen (Switzerland)

    1996-01-01

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

  4. Anaerobic digestion of solid material

    DEFF Research Database (Denmark)

    Vavilin, V.A.; Lokshina, L.Y.; Flotats, X.

    2007-01-01

    A new multidimensional (3 and 2D) anaerobic digestion model for cylindrical reactor with non-uniform influent concentration distributions was developed to study the way in which mixing intensity affects the efficiency of continuous-flow anaerobic digestion. Batch experiments reported and simulate...

  5. Ability for anaerobic growth is not sufficient for development of the petite phenotype in Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Møller, Kasper; Olsson, Lisbeth; Piskur, Jure

    2001-01-01

    Saccharomyces cerevisiae is a petite-phenotype-positive ("petite-positive") yeast, which can successfully grow in the absence of oxygen. On the other hand, Kluyveromyces lactis as well as many other yeasts are petite negative and cannot grow anaerobically. In this paper, we show that Saccharomyces...... kluyveri can grow under anaerobic conditions, but while it can generate respiration-deficient mutants, it cannot generate true petite mutants. From a phylogenetic point of view, S. kluyveri is apparently more closely related to S. cerevisiae than to K. lactis. These observations suggest that the progenitor...... of the modern Saccharomyces and Kluyveromyces yeasts, as well as other related genera, was a petite-negative and aerobic yeast. Upon separation of the K. lactis and S. kluyveri-S. cerevisiae lineages, the latter developed the ability to grow anaerobically. However, while the S. kluyveri lineage has remained...

  6. Methane production and microbial community structure for alkaline pretreated waste activated sludge.

    Science.gov (United States)

    Sun, Rui; Xing, Defeng; Jia, Jianna; Zhou, Aijuan; Zhang, Lu; Ren, Nanqi

    2014-10-01

    Alkaline pretreatment was studied to analyze the influence on waste activated sludge (WAS) reduction, methane production and microbial community structure during anaerobic digestion. Methane production from alkaline pretreated sludge (A-WAS) (pH = 12) increased from 251.2 mL/Ld to 362.2 mL/Ld with the methane content of 68.7% compared to raw sludge (R-WAS). Sludge reduction had been improved, and volatile suspended solids (VSS) removal rate and protein reduction had increased by ∼ 10% and ∼ 35%, respectively. The bacterial and methanogenic communities were analyzed using 454 pyrosequencing and clone libraries of 16S rRNA gene. Remarkable shifts were observed in microbial community structures after alkaline pretreatment, especially for Archaea. The dominant methanogenic population changed from Methanosaeta for R-WAS to Methanosarcina for A-WAS. In addition to the enhancement of solubilization and hydrolysis of anaerobic digestion of WAS, alkaline pretreatment showed significant impacts on the enrichment and syntrophic interactions between microbial communities.

  7. [Effects of Tillage on Soil Respiration and Root Respiration Under Rain-Fed Summer Corn Field].

    Science.gov (United States)

    Lu, Xing-li; Liao, Yun-cheng

    2015-06-01

    To explore the effects of different tillage systems on soil respiration and root respiration under rain-fed condition. Based on a short-term experiment, this paper investigated soil respiration in summer corn growth season under four tillage treatments including subsoiling tillage (ST), no tillage (NT), rotary tillage (RT) and moldboard plow tillage (CT). The contribution of root respiration using root exclusion method was also discussed. The results showed that soil respiration rate presented a single peak trend under four tillage methods during the summer corn growing season, and the maximum value was recorded at the heading stage. The trends of soil respiration were as follows: heading stage > flowering stage > grain filling stage > maturity stage > jointing stage > seedling stage. The trends of soil respiration under different tillage systems were as follows: CT > ST > RT > NT. There was a significant correlation between soil respiration rate and soil temperatures (P tillage systems. Therefore, root exclusion method could be used to study the contribution of crop growth to carbon emission, to compare effects of different tillage systems on the contribution of root respiration provides the bases for selecting the measures to slow down the decomposition of soil carbon.

  8. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  9. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  10. 78 FR 18601 - Respirator Certification Fees; Public Meeting

    Science.gov (United States)

    2013-03-27

    ... HUMAN SERVICES Centers for Disease Control and Prevention Respirator Certification Fees; Public Meeting... stakeholders to present information the impact of an increase on respirator fees on individual respirator manufacturers, the respirator market, or on those industries that rely on NIOSH approved respiratory...

  11. 42 CFR 84.174 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.174... Air-Purifying Particulate Respirators § 84.174 Respirator containers; minimum requirements. (a) Except as provided in paragraph (b) of this section each respirator shall be equipped with a...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Pretreatment of wheat straw and conversion of xylose and xylan to ethanol by thermophilic anaerobic bacteria

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær; Jensen, K.; Nielsen, P.

    1996-01-01

    Wheat straw was pretreated by wet oxidation (oxygen pressure, alkaline conditions, elevated temperature) or hydrothermal processing (without oxygen) in order to solubilize the hemicellulose, facilitating bio-conversion. The effect of oxygen pressure and sodium carbonate addition on hemicellulose...... solubilization was investigated. The two process parameters had little effect on the solubilization of hemicellulose. However alkaline conditions affected the furfural formation whereas oxygen had no effect. After pretreatment, the filtrate was used as a fermentation medium for thermophilic anaerobic bacterin...... of the microorganism to the wet oxidized filtrate was also examined. Copyright (C) 1997 Elsevier Science Ltd....

  14. Re-interpreting anaerobic metabolism: an argument for the application of both anaerobic glycolysis and excess post-exercise oxygen comsumption (EPOC) as independent sources of energy expenditure.

    Science.gov (United States)

    Scott, C B

    1998-02-01

    Due to current technical difficulties and changing cellular conditions, the measurement of anaerobic and recovery energy expenditure remains elusive. During rest and low-intensity steady-state exercise, indirect calorimetric measurements successfully represent energy expenditure. The same steady-state O2 uptake methods are often used to describe the O2 deficit and excess post-oxygen consumption (EPOC): 1 l O2 = 5 kcal = 20.9 kJ. However, an O2 deficit plus exercise O2 uptake measurement ignores energy expenditure during recovery, and an exercise O2 uptake plus EPOC measurement misrepresents anaerobic energy expenditure. An alternative solution has not yet been proposed. Anaerobic glycolysis and mitochondrial respiration are construed here as a symbiotic union of metabolic pathways, each contributing independently to energy expenditure and heat production. Care must be taken when using O2 uptake alone to quantify energy expenditure because various high-intensity exercise models reveal that O2 uptake can lag behind estimated energy demands or exceed them. The independent bioenergetics behind anaerobic glycolysis and mitochondrial respiration can acknowledge these discrepancies. Anaerobic glycolysis is an additive component to an exercise O2 uptake measurement. Moreover, it is the assumptions behind steady-state O2 uptake that do not permit proper interpretation of energy expenditure during EPOC; 1 l O2 not = 20.9 kJ. Using both the O2 deficit and a modified EPOC for interpretation, rather than one or the other, leads to a better method of quantifying energy expenditure for higher intensity exercise and recovery.

  15. Thermochemical Pretreatment for Anaerobic Digestion of Sorted Waste

    Science.gov (United States)

    Hao, W.; Hongtao, W.

    2008-02-01

    The effect of alkaline hydrothermal pre-treatment for anaerobic digestion of mechanically-sorted municipal solid waste (MSW) and source-sorted waste was studied. Waste was hydrothermally pre-treated in dilute alkali solution. Hydrolysis product was incubated in 500 ml saline bottle to determine methane potential (MP) under mesospheric anaerobic conditions. Optimum reaction condition obtained in the study is 170 °C at the dose of 4 g NaOH/100 g solid for one hour. Soluble COD was 13936 mg/L and methane yield was 164 ml/g VS for 6 days incubation at optimum conditions. More than 50% biogas increase was achieved over the control, and methane conversion ratio on carbon basis was enhanced to 30.6%. The digestion period was less than 6 days when pre-treatment temperature was above 130 °C. The organic part of sorted waste is mainly constituted of kitchen garbage and leaf. Model kitchen garbage was completely liquidized at 130 °C for one hour and the methane yield was 276 ml/g VS. Addition of alkali enhance hydroxylation rate and methane yield slightly. The biogas potential of leaf could be observed by pre-treatment above 150 °C under alkaline condition.

  16. Plant Respiration and Climate Change Effects

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, D.

    2002-04-01

    Plant respiration is one of the key processes in terms of an understanding of plant growth and functioning in a future climate. Short- and long-term effects of temperature and CO{sub 2} on plant respiration were investigated in a number of plant species. The experiments tested effects of either temperature and/or CO{sub 2} from the level of individual respiratory enzymes, isolated mitochondria, whole-tissue, and up to the whole canopy level. The short-term effects of elevated atmospheric CO{sub 2} on plant respiration appeared to be less than suggested so far in the literature. This was true both at the tissue level and for intact mitochondria. Respiratory enzymes can, however, be affected already at low CO{sub 2}. These effects did not manifest itself at the tissue level, though, due to low degrees of control on the whole respiratory process exerted by the particular enzymes. Plant respiration on the other hand was affected by long-term growth at elevated atmospheric CO{sub 2}. The findings of the reduced plant respiration at the leaf level were consistent with the literature and potential causes are discussed. Short-term effects of temperature on plant respiration were demonstrated to be dependent on the actual measurement temperature. Further, it is shown that mitochondrial leaf respiration in darkness and light differ substantially in the temperature sensitivity with the former being the far most sensitive. This has implications for modelling CO{sub 2} exchange between vegetation and atmosphere as demonstrated here, since this has so far been neglected. Long-term effects of temperature resulted in respiratory acclimation in a number of species. Respiratory acclimation appeared not to occur to any one single type of growth temperature. The implications of this finding in combination with the timing of acclimation are discussed for modelling respiratory CO{sub 2} release. (au)

  17. 2nd Generation Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Yde, Lars; Kjartansdóttir, Cecilia Kristin; Allebrod, Frank;

    This report provides the results of the 2nd Generation Alkaline Electrolysis project which was initiated in 2008. The project has been conducted from 2009-2012 by a consortium comprising Århus University Business and Social Science – Centre for Energy Technologies (CET (former HIRC)), Technical...

  18. Growth of silicone-immobilized bacteria on polycarbonate membrane filters, a technique to study microcolony formation under anaerobic conditions

    DEFF Research Database (Denmark)

    Højberg, Ole; Binnerup, S. J.; Sørensen, Jan

    1997-01-01

    A technique was developed to study microcolony formation by silicone- immobilized bacteria on polycarbonate membrane filters under anaerobic conditions. A sudden shift to anaerobiosis was obtained by submerging the filters in medium which was depleted for oxygen by a pure culture of bacteria....... The technique was used to demonstrate that preinduction of nitrate reductase under low-oxygen conditions was necessary for nonfermenting, nitrate-respiring bacteria, e.g., Pseudomonas spp., to cope with a sudden lack of oxygen. In contrast, nitrate-respiring, fermenting bacteria, e.g., Bacillus and Escherichia...

  19. Alkaline resistant ceramics; Alkalimotstaandskraftiga keramer

    Energy Technology Data Exchange (ETDEWEB)

    Westberg, Stig-Bjoern [Vattenfall Utveckling AB, Aelvkarleby (Sweden)

    2001-02-01

    Despite durability in several environments, ceramics and refractories can not endure alkaline environments at high temperature. An example of such an environment is when burning biofuel in modern heat and power plants in which the demand for increasing efficiency results in higher combustion temperatures and content of alkaline substances in the flue gas. Some experiences of these environments has been gained from such vastly different equipment as regenerator chambers in the glass industry and MHD-generators. The grains of a ceramic material are usually bonded together by a glassy phase which despite it frequently being a minor constituent render the materials properties and limits its use at elevated temperature. The damage is usually caused by alkaline containing low-melting phases and the decrease of the viscosity of the bonding glass phase which is caused by the alkaline. The surfaces which are exposed to the flue gas in a modern power plant are not only exposed to the high temperature but also a corroding and eroding, particle containing, gas flow of high velocity. The use of conventional refractory products is limited to 1300-1350 deg C. Higher strength and fracture toughness as well as durability against gases, slag and melts at temperatures exceeding 1700 deg C are expected of the materials of the future. Continuous transport of corrosive compounds to the surface and corrosion products from the surface as well as a suitable environment for the corrosion to occur in are prerequisites for extensive corrosion to come about. The highest corrosion rate is therefore found in a temperature interval between the dew point and the melting point of the alkaline-constituent containing compound. It is therefore important that the corrosion resistance is sufficient in the environment in which alkaline containing melts or slag may appear. In environments such as these, even under normal circumstances durable ceramics, such as alumina and silicon carbide, are attacked

  20. Isolation and Cultivation of Anaerobes

    DEFF Research Database (Denmark)

    Aragao Börner, Rosa

    2016-01-01

    Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts.In view of that, the isolation and cultivation of anaerobic...... microorganisms is still a promising venture, and conventional methodologies as well as considerations and modifications are presented here. An insight into new methodologies and devices as well as a discussion on future perspectives for the cultivation of anaerobes may open the prospects of the exploitation...

  1. Plankton respiration in the Eastern Atlantic Ocean

    Science.gov (United States)

    Robinson, Carol; Serret, Pablo; Tilstone, Gavin; Teira, Eva; Zubkov, Mikhail V.; Rees, Andrew P.; Woodward, E. Malcolm S.

    2002-05-01

    Concurrent measurements of dark community respiration (DCR), gross production (GP), size fractionated primary production ( 14C PP), nitrogen uptake, nutrients, chlorophyll a concentration, and heterotrophic and autotrophic bacterial abundance were collected from the upper 200 m of a latitudinal (32°S-48°N) transect in the Eastern Atlantic Ocean during May/June 1998. The mean mixed layer respiration rate was 2.5±2.1 mmol O 2 m -3 d -1 ( n=119) for the whole transect, 2.2±1.1 mmol O 2 m -3 d -1 ( n=32) in areas where chlorophyll a was dissolved oxygen consumption, was 0.8 ( n=11). At the time of the study, plankton community respiration exceeded GP in the picoautotroph dominated oligotrophic regions (Eastern Tropical Atlantic [15.5°S-14.2°N] and North Atlantic Subtropical Gyre [21.5-42.5°N]), which amounted to 50% of the stations sampled along the 12,100 km transect. These regions also exhibited high heterotrophic: autotrophic biomass ratios, higher turnover rates of phytoplankton than of bacteria and low f ratios. However, the carbon supply mechanisms required to sustain the rates of respiration higher than GP could not be fully quantified. Future research should aim to determine the temporal balance of respiration and GP together with substrate supply mechanisms in these ocean regions.

  2. Optical tweezers and non-ratiometric fluorescent-dye-based studies of respiration in sperm mitochondria

    Science.gov (United States)

    Chen, Timothy; Shi, Linda Z.; Zhu, Qingyuan; Chandsawangbhuwana, Charlie; Berns, Michael W.

    2011-04-01

    The purpose of this study is to investigate how the mitochondrial membrane potential affects sperm motility using laser tweezers and a non-ratiometric fluorescent probe, DiOC6(3). A 1064 nm Nd:YVO4 continuous wave laser was used to trap motile sperm at a power of 450 mW in the trap spot. Using customized tracking software, the curvilinear velocity (VCL) and the escape force from the laser tweezers were measured. Human (Homo sapiens), dog (Canis lupis familiaris) and drill (Mandrillus leucophaeus) sperm were treated with DiOC6(3) to measure the membrane potential in the mitochondria-rich sperm midpieces. Sperm from all three species exhibited an increase in fluorescence when treated with the DiOC6(3). When a cyanide inhibitor (CCCP) of aerobic respiration was applied, sperm of all three species exhibited a reduction in fluorescence to pre-dye levels. With respect to VCL and escape force, the CCCP had no effect on dog or human sperm, suggesting a major reliance upon anaerobic respiration (glycolysis) for ATP in these two species. Based on the preliminary study on drill sperm, CCCP caused a drop in the VCL, suggesting potential reliance on both glycolysis and aerobic respiration for motility. The results demonstrate that optical trapping in combination with DiOC6(3) is an effective way to study sperm motility and energetics.

  3. Key respiratory genes elucidate bacterial community respiration in a seasonally anoxic estuary.

    Science.gov (United States)

    Eggleston, Erin M; Lee, Dong Y; Owens, Michael S; Cornwell, Jeffrey C; Crump, Byron C; Hewson, Ian

    2015-07-01

    Intense annual spring phytoplankton blooms and thermohaline stratification lead to anoxia in Chesapeake Bay bottom waters. Once oxygen becomes depleted in the system, microbial communities use energetically favourable alternative electron acceptors for respiration. The extent to which changes in respiration are reflected in community gene expression have only recently been investigated. Metatranscriptomes prepared from near-bottom water plankton over a 4-month time series in central Chesapeake Bay demonstrated changes consistent with terminal electron acceptor availability. The frequency of respiration-related genes in metatranscriptomes was examined by BLASTx against curated databases of genes intimately and exclusively involved in specific electron acceptor utilization pathways. The relative expression of genes involved in denitrification and dissimilatory nitrate reduction to ammonium were coincident with changes in nitrate, nitrite and ammonium concentrations. Dissimilatory iron and manganese reduction transcript ratios increase during anoxic conditions and corresponded with the highest soluble reactive phosphate and manganese concentrations. The sulfide concentration peaked in late July and early August and also matched dissimilatory sulfate reduction transcript ratios. We show that rather than abrupt transitions between terminal electron acceptors, there is substantial overlap in time and space of these various anaerobic respiratory processes in Chesapeake Bay.

  4. Anaerobic methane oxidation in a landfill-leachate plume.

    Science.gov (United States)

    Grossman, Ethan L; Cifuentes, Luis A; Cozzarelli, Isabelle M

    2002-06-01

    The alluvial aquifer adjacent to Norman Landfill, OK, provides an excellent natural laboratory for the study of anaerobic processes impacting landfill-leachate contaminated aquifers. We collected groundwaters from a transect of seven multilevel wells ranging in depth from 1.3 to 11 m that were oriented parallel to the flow path. The center of the leachate plume was characterized by (1) high alkalinity and elevated concentrations of total dissolved organic carbon, reduced iron, and methane, and (2) negligible oxygen, nitrate, and sulfate concentrations. Methane concentrations and stable carbon isotope (delta13C) values suggest anaerobic methane oxidation was occurring within the plume and at its margins. Methane delta13C values increased from about -54 per thousand near the source to > -10 per thousand downgradient and at the plume margins. The isotopic fractionation associated with this methane oxidation was -13.6+/-1.0 per thousand. Methane 13C enrichment indicated that 80-90% of the original landfill methane was oxidized over the 210-m transect. First-order rate constants ranged from 0.06 to 0.23 per year, and oxidation rates ranged from 18 to 230 microM/y. Overall, hydrochemical data suggest that a sulfate reducer-methanogen consortium may mediate this methane oxidation. These results demonstrate that natural attenuation through anaerobic methane oxidation can be an important sink for landfill methane in aquifer systems.

  5. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  6. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  7. Experimental study on soil respiration of temperate grassland in China

    Institute of Scientific and Technical Information of China (English)

    WANG Gengchen; DU Rui; KONG Qinxin; L(U) Daren

    2004-01-01

    Experimental study on soil respiration of typical temperate grassland in Inner Mongolia was conducted in the period of 1998-2000. Closed chamber and GC/FID techniques were used for measurements of soil and plant respiration. Data analysis of three-year measurements show that temperate grassland soil respiration varied in the range of 390-866 gC/m2·a-1 and underwent evident seasonal and annual variations. On average, the soil respiration accounts for 70%-88% of the grassland total respiration. Results also show a stronger relation between the soil respiration and soil temperature in water abundant years. Increased rainfall in 1998 made soil respiration increased, while in the dry years, the relation between soil respiration and soil temperature weakened remarkably. Soit water content plays an important controlling role in soil respiration-temperature interrelation for semiarid grassland.

  8. Modelling of the mesophilic anaerobic co-digestion of olive mill wastewater with olive mill solid waste using anaerobic digestion model No. 1 (ADM1).

    Science.gov (United States)

    Boubaker, Fezzani; Ridha, Ben Cheikh

    2008-09-01

    The anaerobic digestion model No. 1 (ADM1), conceived by the international water association (IWA) task group for mathematical modelling of anaerobic digestion processes is a structured generic model which includes multiples steps describing biochemical and physicochemical processes encountered in the anaerobic degradation of complex organic substrates and a common platform for further model enhancement and validation of dynamic simulations for a variety of anaerobic processes. In this study the ADM1 model was modified and applied to simulate the mesophilic anaerobic co-digestion of olive mill wastewater (OMW) with olive mill solid waste (OMSW). The ADM1 equations were coded and implemented using the simulation software package MATLAB/Simulink. The most sensitive parameters were calibrated and validated using updated experimental data of our previous work. The results indicated that the ADM1 model could simulate with good accuracy: gas flows, methane and carbon-dioxide contents, pH and total volatile fatty acids (TVFA) concentrations of effluents for various feed concentrations digested at different hydraulic retention times (HRTs) and especially at HRTs of 36 and 24 days. Furthermore, effluent alkalinity and ammonium nitrogen were successfully predicted by the model at HRTs of 12 and 24 days for some feed concentrations.

  9. Soil Respiration During a Soybean-Growing Season

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Soil respiration induced by soybean cultivation over its entire growing season and the factors influencing soil respiration were investigated to examine the seasonal pattern of soil respiration induced by soybean cultivation, explore soybean growth and photosynthesis on soil respiration, and determine the temperature dependence on soil respiration. Soil respiration in a pot experiment with and without soybean plants was sampled using the static chamber method and measured using gas chromatograph. Air temperature was a dominant factor controlling soil respiration rate in unplanted soil. Additionally,rhizosphere respiration comprised 62% to 98% of the soil respiration rate in the soybean-planted soil varying with the soybean growth stages. Harvesting aerial parts of soybean plant caused an immediate drop in the soil respiration rate at that stage. After harvesting the aerial parts of the soybean plant, a highly significant correlation between soil respiration rate and air temperature was found at the flowering stage (P < 0.01), the pod stage (P < 0.01), and the seed-filling stage(P < 0.05). Thus, rhizosphere respiration during the soybean-growing period not only made a great contribution to soil respiration, but also determined the seasonal variation pattern of the soil respiration rate.

  10. Soil respiration partition and its components in the total agro-ecosystem respiration

    Science.gov (United States)

    Delogu, Emilie; LeDantec, Valerie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, Elizabeth; Mary, Bruno

    2013-04-01

    Close to 15% of the Earth's terrestrial surface is used for cropland. In the context of global warming, and acknowledged by the Kyoto Protocol, agricultural soils could be a significant sink for atmospheric CO2. Understanding the factors influencing carbon fluxes of agricultural soils is essential for implementing efficient mitigation practices. Most of the soil respiration modeling studies was carried out in forest ecosystems, but only a few was carried out in agricultural ecosystems. In the study, we evaluated simple formalisms to model soil respiration using wheat data from four contrasting geographical mi-latitude regions. Soil respiration were measured in three winter wheat fields at Lamasquère (43°49'N, 01°23'E, 2007) and Auradé (43°54'N, 01°10'E, 2008), South-West France and Lonzée (50°33'N, 4°44'E, 2007), Belgium, and in a spring wheat field at Ottawa (45°22'N, 75°43'W, 2007, 2011), Ontario, Canada. Manual closed chambers were used in the French sites. The Belgium and Canadian sites were equipped with automated closed chamber systems, which continuously collected 30-min soil respiration exchanges. All the sites were also equipped with eddy flux towers. When eddy flux data were collected over bare soil, the net ecosystem exchange (NEE) was equal to soil respiration exchange. These NEE data were used to validate the model. Different biotic and abiotic descriptors were used to model daily soil respiration and its heterotrophic and autotrophic components: soil temperature, soil relative humidity, Gross Primary Productivity (GPP), shoot biomass, crop height, with different formalisms. It was interesting to conclude that using biotic descriptors did not improve the performances of the model. In fact, a combination of abiotic descriptors (soil humidity and soil temperature) allowed significant model formalism to model soil respiration. The simple soil respiration model was used to calculate the heterotrophic and autotrophic source contributions to

  11. Influence of leachate recirculation on aerobic and anaerobic decomposition of solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Bilgili, M. Sinan [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: ahmetd@yildiz.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: bozkaya@yildiz.edu.tr

    2007-05-08

    In this study, the effect of leachate recirculation on aerobic and anaerobic degradation of municipal solid wastes is determined by four laboratory-scale landfill reactors. The options studied and compared with the traditional anaerobic landfill are: leachate recirculation, landfill aeration, and aeration with leachate recirculation. Leachate quality is regularly monitored by the means of pH, alkalinity, total dissolved solids, conductivity, oxidation-reduction potential, chloride, chemical oxygen demand, ammonia, and total Kjeldahl nitrogen, in addition to generated leachate quantity. Aerobic leachate recirculated landfill appears to be the most effective option in the removal of organic matter and ammonia. The main difference between aerobic recirculated and non-recirculated landfill options is determined at leachate quantity. Recirculation is more effective on anaerobic degradation of solid waste than aerobic degradation. Further studies are going on to determine the optimum operational conditions for aeration and leachate recirculation rates, also with the operational costs of aeration and recirculation.

  12. A rapid in situ respiration test for measuring aerobic biodegradation rates of hydrocarbons in soil.

    Science.gov (United States)

    Hinchee, R E; Ong, S K

    1992-10-01

    An in situ test method to measure the aerobic biodegradation rates of hydrocarbons in contaminated soil is presented. The test method provides an initial assessment of bioventing as a remediation technology for hydrocarbon-contaminated soil. The in situ respiration test consists of ventilating the contaminated soil of the unsaturated zone with air and periodically monitoring the depletion of oxygen (O2) and production of carbon dioxide (CO2) over time after the air is turned off. The test is simple to implement and generally takes about four to five days to complete. The test was applied at eight hydrocarbon-contaminated sites of different geological and climatic conditions. These sites were contaminated with petroleum products or petroleum fuels, except for two sites where the contaminants were primarily polycyclic aromatic hydrocarbons. Oxygen utilization rates for the eight sites ranged from 0.02 to 0.99 percent O2/hour. Estimated biodegradation rates ranged from 0.4 to 19 mg/kg of soil/day. These rates were similar to the biodegradation rates obtained from field and pilot studies using mass balance methods. Estimated biodegradation rates based on O2 utilization were generally more reliable (especially for alkaline soils) than rates based on CO2 production. CO2 produced from microbial respiration was probably converted to carbonate under alkaline conditions.

  13. Anaerobic Biodegradation of Detergent Surfactants

    OpenAIRE

    Erich Jelen; Ute Merrettig-Bruns

    2009-01-01

    Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have str...

  14. Improving methane production and phosphorus release in anaerobic digestion of particulate saline sludge from a brackish aquaculture recirculation system.

    Science.gov (United States)

    Zhang, Xuedong; Ferreira, Rui B; Hu, Jianmei; Spanjers, Henri; van Lier, Jules B

    2014-06-01

    In this study, batch tests were conducted to examine the effects of trehalose and glycine betaine as well as potassium on the specific methanogenic activity (SMA), acid and alkaline phosphatase activity of anaerobic biomass and phosphorus release in anaerobic digestion of saline sludge from a brackish recirculation aquaculture system. The results of ANOVA and Tukey's HSD (honestly significant difference) tests showed that glycine betaine and trehalose enhanced SMA of anaerobic biomass and reactive phosphorus release from the particulate waste. Moreover, SMA tests revealed that methanogenic sludge, which was long-term acclimatized to a salinity level of 17 g/L was severely affected by the increase in salinity to values exceeding 35 g/L. Addition of compatible solutes, such as glycine betaine and trehalose, could be used to enhance the specific methane production rate and phosphorus release in anaerobic digestion from particulate organic waste produced in marine or brackish aquaculture recirculation systems.

  15. BOREAS TE-2 Wood Respiration Data

    Science.gov (United States)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  16. BOREAS TE-2 Foliage Respiration Data

    Science.gov (United States)

    Ryan, Michael G.; Hall, Forrest G. (Editor); Lavigne, Michael; Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of foliar respiration conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  17. BOREAS TE-2 Root Respiration Data

    Science.gov (United States)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  18. BOREAS TE-2 Continuous Wood Respiration Data

    Science.gov (United States)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Ryan, Michael G.; Lavigne, Michael

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration measured continuously (about once per hour) in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  19. Management effects on European cropland respiration

    DEFF Research Database (Denmark)

    Eugster, Werner; Moffat, Antje M.; Ceschia, Eric

    2010-01-01

    Increases in respiration rates following management activities in croplands are considered a relevant anthropogenic source of CO2. In this paper, we quantify the impact of management events on cropland respiration fluxes of CO2 as they occur under current climate and management conditions. Our...... findings are based on all available CarboEurope IP eddy covariance flux measurements during a 4-year period (2004–2007). Detailed management information was available for 15 out of the 22 sites that contributed flux data, from which we compiled 30 types of management for European-scale comparison...

  20. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation.

    Science.gov (United States)

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  1. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation

    Science.gov (United States)

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  2. Contribution of Root Respiration to Total Soil Respiration in a Cotton Field of Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhi-Min; ZHAO Cheng-Yi; Y.YILIHAMU; LI Ju-Yan; LI Jun

    2013-01-01

    To measure the contribution of root respiration (Rr) to total soil respiration (Rt) in arid cotton fields,eighteen plots,nine for girdling and nine control,were built in an arid cotton field in the Aksu National Experimental Station of Oasis Farmland Ecosystem,Xinjiang of China.Given the difference of soil respiration between girdled plots and non-girdled control plots,the components of soil respiration,root respiration (Rr) and respiration originating from decomposition (Rd) were divided.The temperature sensitivities of Rr and Rd were analyzed,respectively.The results showed that the average contribution of Rr to Rt in arid cotton field was about 32% during the study period.The temperature-response curve of Rr differed from that of Rd.The dynamic variation of Rd was more related to the change of soil temperature as compared to Rr.Rr and Rd had different responses to the variation of environment,and thus new models capable of differentiating between Rr and Rd are needed for evaluating the different factors controlling these two components of soil respiration in arid cotton field.

  3. Development of alkaline fuel cells.

    Energy Technology Data Exchange (ETDEWEB)

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassovs research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herrings group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  4. Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline Hydrothermal Vents

    Science.gov (United States)

    Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua

    2016-09-01

    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel hydrothermal system in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature hydrothermal fluids were generated in basalt-hosted hydrothermal vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent systems. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline hydrothermal vents in origin of life in the early ocean.

  5. Treatment of Alkaline Stripped Effluent in Aerated Constructed Wetlands: Feasibility Evaluation and Performance Enhancement

    Directory of Open Access Journals (Sweden)

    Keli He

    2016-09-01

    Full Text Available Ammonium stripping has gained increasing interest for nitrogen recovery in anaerobically digested effluents. However, the stripped effluents often still do not meet discharge standards, having high pH and residual pollutants. Constructed wetlands (CWs are an easy to operate ecosystem and have a long history of application in treatment of wastewaters with extreme pH, such as acid mine drainage. However, knowledge of the mechanistic details involved in the use of CWs to treat high alkaline drainage, such as stripped effluent, is insufficient. This study explored the feasibility and effectiveness of using three sub-surface horizontal flow CWs to treat high alkaline stripped effluent (pH > 10. Two intensification strategies—intermittent aeration and effluent recirculation—were evaluated to enhance nitrogen depuration performance. The results show that the treatment of alkaline stripped effluent is feasible due to the high buffering capacity of the wetlands. Effluent recirculation combined with intermittent artificial aeration improves nitrogen removal, with 71% total nitrogen (TN removal. Ammonia volatilization from the surface of the wetlands in high alkaline conditions only contributed to 3% of the total removed ammonium. The microbial abundance and activity had significant diversity for the various enhancement strategies used in the constructed wetland systems. Anammox is an important process for nitrogen removal in CWs treating alkaline stripped effluent, and possible enhancements of this process should be investigated further.

  6. Combined alkaline and ultrasonic pretreatment of sludge before aerobic digestion

    Institute of Scientific and Technical Information of China (English)

    JIN Yiying; LI Huan; MAHAR Rasool Bux; WANG Zhiyu; NIE Yongfeng

    2009-01-01

    Alkaline and ultrasonic sludge disintegration can both be used as pretreatments of waste activated sludge (WAS) for improving the subsequent anaerobic or aerobic digestion. The pretreatment has been carried out using different combination of these two methods in this study. The effect was evaluated based on the quantity of soluble chemical oxygen demand (SCOD) in the pretreated sludge as well as the degradation of organic matter in the following aerobic digestion. For WAS samples with combined pretreatment, the released COD was in high level than those with ultrasonic or alkaline treatment. When combined with the same ultrasonic treatment, NaOH treatment resulted in more solubilization of WAS than Ca(OH)2. For combined NaOH and ultrasonic treatments with different sequences, the released COD were in the order: simultaneous treatment > ultrasonic treatment following NaOH treatment > NaOH treatment following ultrasonic treatment. For simultaneous treatment, low NaOH dosage (100 g/kg dry solid), short duration (30 min) of NaOH treatment, and low ultrasonic specific energy (7 500 kJ/kg dry solid) were beneficial for sludge disintegration. Using combined NaOH and ultrasonic pretreatment with the optimium parameters, the degradation efficiency of organic matter was increased from 38.0% to 50.7%, which is much higher than with ultrasonic (42.5%) or with NaOH pretreatment (43.5%) in the subsequent aerobic digestion at the same retention time.

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

    Science.gov (United States)

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

    2016-04-01

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

  8. Phosphorus Mobilization from Manure-Amended and Unamended Alkaline Soils to Overlying Water during Simulated Flooding.

    Science.gov (United States)

    Amarawansha, E A G S; Kumaragamage, D; Flaten, D; Zvomuya, F; Tenuta, M

    2015-07-01

    Anaerobic soil conditions resulting from flooding often enhance release of phosphorus (P) to overlying water. Enhanced P release is well documented for flooded acidic soils; however, there is little information for flooded alkaline soils. We examined the effect of flooding and anaerobic conditions on P mobilization using 12 alkaline soils from Manitoba that were either unamended or amended with solid cattle manure. Pore water and floodwater were analyzed over 8 wk of simulated flooding for dissolved reactive P (DRP), Ca, Mg, Fe, and Mn. As expected, manured soils had significantly greater pore and floodwater DRP concentrations than unamended. Flooding increased pore water DRP concentrations significantly in all soils and treatments except one manured clay in which concentrations increased initially and then decreased. Floodwater DRP concentrations increased significantly by two- to 15-fold in 10 soils regardless of amendment treatment but remained relatively stable in the two soils with greatest clay content. Phosphorus release at the onset of flooding was associated with the release of Ca, Mg, and Mn, suggesting that P release may be controlled by the dissolution of Mg and Ca phosphates and reductive dissolution of Mn phosphates. Thereafter, P release was associated with release of Fe, suggesting the reductive dissolution of Fe phosphates. Differences in pore water and floodwater DRP concentrations among soils and amendment treatments and the high variability in P mobilization from pore water to floodwater among soils indicate the need to further investigate chemical reactions responsible for P release and mobility under anaerobic conditions.

  9. Anaerobic treatment of Tequila vinasses in a CSTR-type digester.

    Science.gov (United States)

    Méndez-Acosta, Hugo Oscar; Snell-Castro, Raúl; Alcaraz-González, Víctor; González-Alvarez, Víctor; Pelayo-Ortiz, Carlos

    2010-06-01

    Tequila industries in general produce great volumes of effluents with high pollutant loads, which are discharged (untreated or partially treated) into natural receivers, thus causing severe environmental problems. In this contribution, we propose an integrated system as a first step to comply with the Mexican ecological norms and stabilize the anaerobic treatment of Tequila vinasses with main design criteria: simple and easy operation, reduce operating time and associated costs (maintenance), integrated and compact design, minimal cost of set-up, start-up, monitoring and control. This system is composed of a fully instrumented and automated lab-scale CSTR-type digester, on-line measuring devices of key variables (pH, temperature, flow rates, etc.), which are used along with off-line readings of chemical oxygen demand (COD), biogas composition, alkalinity and volatile fatty acids to guarantee the operational stability of the anaerobic digestion process. The system performance was evaluated for 200 days and the experimental results show that even under the influence of load disturbances, it is possible to reduce the COD concentration to 85% in the start-up phase and up to 95% during the normal operation phase while producing a biogas with a methane composition greater than 65%. It is also shown that in order to maintain an efficient treatment, the buffering capacity (given by the alkalinity ratio, alpha = intermediate alkalinity/total alkalinity) must be closely monitored.

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

    Directory of Open Access Journals (Sweden)

    A. Bannert

    2012-10-01

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

  11. Respiration in Heterotrophic Unicellular Eukaryotic Organisms

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2014-01-01

    about 10% and mitochondria are predominantly found close to the outer membrane. The results predict that for small and medium sized protozoa maximum respiration rates should be proportional to cell volume (scaling exponent ≈1) and access to intracellular O2 is not limiting except at very low ambient O2...

  12. Maintenance, endogeneous, respiration, lysis, decay and predation

    DEFF Research Database (Denmark)

    loosdrecht, Marc C. M. Van; Henze, Mogens

    1999-01-01

    In activated sludge processes an increased sludge age is associated with a decreased sludge production. This phenomenon is generally interpreted as a result of endogenous respiration processes. In the activated sludge models cell lysis (or decay) is incorporated. The lysis is modelled such that i......In activated sludge processes an increased sludge age is associated with a decreased sludge production. This phenomenon is generally interpreted as a result of endogenous respiration processes. In the activated sludge models cell lysis (or decay) is incorporated. The lysis is modelled...... mechanism is microbiologically correct. The lysis/decay model mechanism is a strongly simplified representation of reality. This paper tries to review the processes grouped under endogenous respiration in activated sludge models. Mechanisms and processes such as maintenance, lysis, internal and external...... and maintenance processes. This conversion will in general be denoted as endogenous respiration. Based on the literature review the phenomena are discussed and organised, in order to create a working platform for discussing more detailed activated sludge models, one of which is being sketched. (C) 1999 IAWQ...

  13. Respiration patterns of resting wasps (Vespula sp.).

    Science.gov (United States)

    Käfer, Helmut; Kovac, Helmut; Stabentheiner, Anton

    2013-04-01

    We investigated the respiration patterns of wasps (Vespula sp.) in their viable temperature range (2.9-42.4°C) by measuring CO2 production and locomotor and endothermic activity. Wasps showed cycles of an interburst-burst type at low ambient temperatures (Ta31°C, CO2 emission became cyclic. With rising Ta they enhanced CO2-emission primarily by an exponential increase in respiration frequency, from 2.6 mHz at 4.7°C to 74 mHz at 39.7°C. In the same range of Ta CO2 release per cycle decreased from 38.9 to 26.4 μl g(-1)cycle(-1). A comparison of wasps with other insects showed that they are among the insects with a low respiratory frequency at a given resting metabolic rate (RMR), and a relatively flat increase of respiratory frequency with RMR. CO2 emission was always accompanied by abdominal respiration movements in all open phases and in 71.4% of the flutter phases, often accompanied by body movements. Results suggest that resting wasps gain their highly efficient gas exchange to a considerable extent via the length and type of respiration movements.

  14. Toward a general evaluation model for soil respiration (GEMSR)

    Institute of Scientific and Technical Information of China (English)

    ZHOU GuangSheng; JIA BingRui; HAN GuangXuan; ZHOU Li

    2008-01-01

    Soil respiration is an important component of terrestrial carbon budget. Its accurate evaluation is essential to the study of terrestrial carbon source/sink. Studies on soil respiration at present mostly focus on the temporal variations and the controlling factors of soil respiration, but its spatial variations and controlling factors draw less attention. Moreover, the evaluation models for soil respiration at present include only the effects of water and heat factors, while the biological and soil factors controlling soil respiration and their interactions with water and heat factors have not been considered yet. These models are not able to accurately evaluate soil respiration in different vegetation/terrestrial ecosystems at different temporal and spatial scales. Thus, a general evaluation model for soil respiration (GEMSR)including the interacting meteorological (water and heat factors), soil nutrient and biological factors is suggested in this paper, and the basic procedure developing GEMSR and the research tasks of soil respiration in the future are also discussed.

  15. Toward a general evaluation model for soil respiration (GEMSR)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Soil respiration is an important component of terrestrial carbon budget. Its accurate evaluation is es- sential to the study of terrestrial carbon source/sink. Studies on soil respiration at present mostly focus on the temporal variations and the controlling factors of soil respiration, but its spatial variations and controlling factors draw less attention. Moreover, the evaluation models for soil respiration at present include only the effects of water and heat factors, while the biological and soil factors controlling soil respiration and their interactions with water and heat factors have not been considered yet. These models are not able to accurately evaluate soil respiration in different vegetation/terrestrial ecosystems at different temporal and spatial scales. Thus, a general evaluation model for soil respiration (GEMSR) including the interacting meteorological (water and heat factors), soil nutrient and biological factors is suggested in this paper, and the basic procedure developing GEMSR and the research tasks of soil respiration in the future are also discussed.

  16. Coproduction of hydrogen and methane via anaerobic fermentation of cornstalk waste in continuous stirred tank reactor integrated with up-flow anaerobic sludge bed.

    Science.gov (United States)

    Cheng, Xi-Yu; Li, Qian; Liu, Chun-Zhao

    2012-06-01

    A 10 L continuous stirred tank reactor (CSTR) system was developed for a two-stage hydrogen fermentation process with an integrated alkaline treatment. The maximum hydrogen production rate reached 218.5 mL/L h at a cornstalk concentration of 30 g/L, and the total hydrogen yield and volumetric hydrogen production rate reached 58.0 mL/g-cornstalk and 0.55-0.57 L/L d, respectively. A 10 L up-flow anaerobic sludge bed (UASB) was used for continuous methane fermentation of the effluents obtained from the two-stage hydrogen fermentation. At the optimal organic loading rate of 15.0 g-COD/Ld, the COD removal efficiency and volumetric biogas production rate reached 83.3% and 4.6L/Ld, respectively. Total methane yield reached 200.9 mL/g-cornstalk in anaerobic fermentation with the effluents and alkaline hydrolysate. As a result, the total energy recovery by coproduction of hydrogen and methane with anaerobic fermentation of cornstalk reached 67.1%.

  17. [Endogenous respiration process analysis of heterotrophic biomass and autotrophic biomass based on respiration map ].

    Science.gov (United States)

    Li, Zhi-hua; Bai, Xu-li; Zhang, Qin; Liu, Yi; He, Chun-bo

    2014-09-01

    The endogenous process is an important metabolic part of the activated sludge, and the understanding of this process is still unclear. Characteristics of endogenous respiration for heterotrophic bacteria and autotrophic nitrifiers were analyzed using respirogram. Results showed that both heterotrophic and autotrophic bacteria entered the stage of endogenous respiration at almost the same time, but heterotrophic bacteria first entered the stage of dormancy i. e. , they were easier to recover a higher proportion of biomass during the dormancy stage, indicating that heterotrophic bacteria exhibited strong environmental adaptability. Autotrophic bacteria were, however, quite different. This finding confirmed that autotrophic bacteria were more vulnerable from the viewpoint of endogenous respiration. In addition, the study also found that the increase of endogenous respiration rate ratio reflected the decreased sludge activity. And the proportion of endogenous respiration was an important parameter to characterize the activity of activated sludge, which can be used as a quantitative index for the health status of activated sludge. The findings further deepened the understanding of endogenous respiration process and provided a theoretical basis for the operation and management of wastewater treatment plants.

  18. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Science.gov (United States)

    2010-10-01

    ... resistance will be measured in the facepiece, mouthpiece, hood, or helmet of a pesticide respirator mounted... allowable resistance requirements for pesticide respirators are as follows: Maximum Resistance Type of... 42 Public Health 1 2010-10-01 2010-10-01 false Pesticide respirators; performance...

  19. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84..., Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1134 Respirator containers; minimum requirements. (a) Except as provided...

  20. 75 FR 20546 - Total Inward Leakage Requirements for Respirators

    Science.gov (United States)

    2010-04-20

    ... HUMAN SERVICES 42 CFR Part 84 RIN 0920-AA33 Total Inward Leakage Requirements for Respirators AGENCY... Respirators,'' published in the Federal Register on October 30, 2009 (74 FR 56141). The comment period on this... total inward leakage (TIL) requirements for half-mask air-purifying particulate respirators approved...

  1. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  2. Identification of electrode respiring, hydrocarbonoclastic bacterial strain Stenotrophomonas maltophilia MK2 highlights the untapped potential for environmental bioremediation

    Directory of Open Access Journals (Sweden)

    Krishnaveni Venkidusamy

    2016-12-01

    Full Text Available Electrode respiring bacteria (ERB possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential towards organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8-C36 of petroleum hydrocarbons including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells, maximum current density of 273±8 mA/m2 (1000Ω was produced (power density 113±7 mW/m2 by strain MK2 with a coulombic efficiency of 34.8 %. Further, the presence of possible alkane hydroxylase genes (alkB and rubA in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS.

  3. Identification of Electrode Respiring, Hydrocarbonoclastic Bacterial Strain Stenotrophomonas maltophilia MK2 Highlights the Untapped Potential for Environmental Bioremediation

    Science.gov (United States)

    Venkidusamy, Krishnaveni; Megharaj, Mallavarapu

    2016-01-01

    Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential toward organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8–C36) of petroleum hydrocarbons (PH) including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells (MFCs), maximum current density of 273 ± 8 mA/m2 (1000 Ω) was produced (power density 113 ± 7 mW/m2) by strain MK2 with a coulombic efficiency of 34.8%. Further, the presence of possible alkane hydroxylase genes (alkB and rubA) in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS. PMID:28018304

  4. Assessment of the ability of sludge to degrade PCP under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    R. M. L. Bolaños

    2005-12-01

    Full Text Available The capacity of sludge from different sources to degrade pentachlorophenol (PCP was evaluated. Three 2.5 liter reactors (R1, R2, and R3 were inoculated with different anaerobic sludges, semi continuously fed and maintained in orbital motion at 30±1°C. R1 was inoculated with aerobic sludge and river sediment collected downstream from a pulp and paper plant. R2 received sludge from an anaerobic reactor treating effluents from a paper recycling plant and R3 received anaerobic sludge from a biodigestor treating industrial and domestic effluents. The sludges were first acclimatized to a culture medium generally recommended for organochloride anaerobic degradation studies. The reactors were then subjected to increasing concentrations of PCP from 0.05 to 10.0 mg.l-1. PCP degradation and metabolite formation were monitored using gas chromatography, and the effects of PCP on the anaerobic process were verified by monitoring pH, volatile fatty acids, alkalinity, total suspended solids, and chemical oxygen demand. It was found that PCP did not affect reactor performance. All the sludges displayed the best PCP degradation capacity at a concentration of 0.2 mg.l-1, producing fewer chlorinated metabolites than when higher PCP concentrations were applied. R1 consistently produced fewer chlorinated metabolites, confirming the hypothesis that pre exposure to chlorinated compounds improves the sludge's capacity to degrade PCP.

  5. Potential for anaerobic conversion of xenobiotics

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Dolfing, J.; Haagensen, Frank;

    2003-01-01

    This review covers the latest research on the anaerobic biodegradation of aromatic xenobiotic compounds, with emphasis on surfactants, polycyclic aromatic hydrocarbons, phthalate esters, polychlorinated biphenyls, halogenated phenols, and pesticides. The versatility of anaerobic reactor systems...

  6. RISK FACTORS IN NEONATAL ANAEROBIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    M. S. Tabib

    2008-06-01

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

  7. Arsenic, Anaerobes, and Astrobiology

    Science.gov (United States)

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

    2013-12-01

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

  8. Contribution of Root Respiration to Total Soil Respiration in a Leymus chinensis (Trin.) Tzvel. Grassland of Northeast China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The loss of carbon through root respiration is an important component of grassland carbon budgets. However,few data are available concerning the contribution of root respiration to total soil respiration in grasslands in China. We investigated seasonal variations of soil respiration rate, root biomass, microbial biomass C and organic C content of the soil in a semi-arid Leymus chinensis (Trin.) Tzvel. grassland of northeast China during the 2002 growing season (from May to September). The linear regression relationship between soil respiration rate and root biomass was used to determine the contribution of root respiration to total soil respiration. Soil respiration rate ranged from 2.5 to 11.9 g C/m2 per d with the maximum in late June and minimum in September.The microbial biomass C and organic C content of the soil ranged from 0.3 to 1.5 g C/m2 and from 29 to 34 g C/kg respectively. Root biomass had two peaks, in early June (1.80 kg/m2) and mid-August (1.73 kg/m2). Root respiration rate peaked in mid-August (6.26 g C/m2 per d), whereas microbial respiration rate peaked in late June (7.43 g C/m2 per d). We estimated that the contribution of root respiration to total soil respiration during the growing season ranged from 38% to 76%.

  9. Alkaline Water and Longevity: A Murine Study.

    Science.gov (United States)

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of "deceleration aging factor" as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models.

  10. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic...

  11. The phenomenon of granulation of anaerobic sludge.

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.

    1989-01-01

    Successful high-rate anaerobic wastewater treatment can only be accomplished when the slowgrowing anaerobic biomass is efficiently held back in the anaerobic treatment system. This biomass retention can be achieved in various ways including immobilization of the organisms on fixed materials and immo

  12. A MEMS turbine prototype for respiration harvesting

    Science.gov (United States)

    Goreke, U.; Habibiabad, S.; Azgin, K.; Beyaz, M. I.

    2015-12-01

    The design, manufacturing, and performance characterization of a MEMS-scale turbine prototype is reported. The turbine is designed for integration into a respiration harvester that can convert normal human breathing into electrical power through electromagnetic induction. The device measures 10 mm in radius, and employs 12 blades located around the turbine periphery along with ball bearings around the center. Finite element simulations showed that an average torque of 3.07 μNm is induced at 12 lpm airflow rate, which lies in normal breathing levels. The turbine and a test package were manufactured using CNC milling on PMMA. Tests were performed at respiration flow rates between 5-25 lpm. The highest rotational speed was measured to be 9.84 krpm at 25 lpm, resulting in 8.96 mbar pressure drop across the device and 370 mW actuation power.

  13. Cardiac, Skeletal, and smooth muscle mitochondrial respiration

    DEFF Research Database (Denmark)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I

    2014-01-01

    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial function. Therefore, this study examined mitochondrial respiratory rates in the smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscle. Cardiac......, skeletal, and smooth muscle was harvested from a total of 22 subjects (53±6 yrs) and mitochondrial respiration assessed in permeabilized fibers. Complex I+II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac, skeletal, to smooth muscle (54±1; 39±4; 15......±1 pmol•s(-1)•mg (-1), psmooth muscle (222±13; 115±2; 48±2 umol•g(-1)•min(-1), p

  14. Glycolysis and respiration in yeasts. The Pasteur effect studied by mass spectrometry.

    Science.gov (United States)

    Lloyd, D; Kristensen, B; Degn, H

    1983-06-15

    Simultaneous and continuous measurements of changes in CO2 and O2 concentrations in glucose-metabolizing yeast suspensions by mass spectrometry enabled a study of the Pasteur effect (aerobic inhibition of glycolysis) in Saccharomyces uvarum and Schizosaccharomyces pombe. A different control mechanism operates in Candida utilis to give a damped oscillation after the anaerobic-aerobic transition. The apparent Km values for respiration of the three yeasts were in the range 1.3-1.8 microM-O2. The apparent Km values for O2 of the Pasteur effect were 5 and 13 microM for catabolite-repressed and derepressed S. uvarum respectively and 7 microM for Sch. pombe. These results are discussed with respect to currently accepted mechanisms for the control of glycolysis.

  15. Impact of human activities on soil respiration:A review

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Soil respiration is one of the primary fluxes of carbon between soils and the atmosphere.It is produced by rhizosphere respiration and soil microbial respiration.Soil respiration is not only affected by environmental factors,but also changes with the hu-man-induced disturbances of ecosystems.Land-use,the measures of land management,the pollution of soil,and so on can affect soil respiration and change the soil efflux.According to some research,the authors summed up their impacts on soil respiration by human activities through land-use changes and land-management measures among agroecosystem,grassland ecosystem,and for-est ecosystem.The results showed that (1) when adding fertilization to farmland,the soil respiration will increase;(2) fenced land can decrease soil respiration,while soil respiration in the grazed land at a grassland ecosystem will decline with the increasing of grazing intensity;(3) with grassland fertilization;farmland cultivation;fire,fertilization,and cutting of forest,conflicting results were found in the changes of soil respiration.Perhaps plant species,site condition,and measurement season can lead to different results on soil respiration.

  16. Frost Induces Respiration and Accelerates Carbon Depletion in Trees.

    Directory of Open Access Journals (Sweden)

    Or Sperling

    Full Text Available Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq. cm(-3 yr(-1 on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.

  17. Continuous respirable mine dust monitor development

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, B.K.; Williams, K.L.; Stein, S.W. [and others

    1996-12-31

    In June 1992, the Mine Safety and Health Administration (MSHA) published the Report of the Coal Mine Respirable Dust Task Group, Review of the Program to Control Respirable Coal Mine Dust in the United States. As one of its recommendations, the report called for the accelerated development of two mine dust monitors: (1) a fixed-site monitor capable of providing continuous information on dust levels to the miner, mine operator, and to MSHA, if necessary, and (2) a personal sampling device capable of providing both a short-term personal exposure measurement as well as a full-shift measurement. In response to this recommendation, the U.S. Bureau of Mines initiated the development of a fixed-site machine-mounted continuous respirable dust monitor. The technology chosen for monitor development is the Rupprecht and Patashnick Co., Inc. tapered element oscillating microbalance. Laboratory and in-mine tests have indicated that, with modification, this sensor can meet the humidity and vibration requirements for underground coal mine use. The U.S. Department of Energy Pittsburgh Research Center (DOE-PRC) is continuing that effort by developing prototypes of a continuous dust monitor based on this technology. These prototypes are being evaluated in underground coal mines as they become available. This effort, conducted as a joint venture with MSHA, is nearing completion with every promise of success.

  18. Perspectives of Anaerobic Soil Disinfestation

    NARCIS (Netherlands)

    Lamers, J.G.; Runia, W.T.; Molendijk, L.P.G.; Bleeker, P.O.

    2010-01-01

    Biological soil disinfestation is an environmentally friendly method to disinfest soil. From now on we refer to it as anaerobic soil disinfestation (ASD). With ASD a green manure crop (40 t/ha) is homogeneously incorporated into the topsoil (0-30 cm) after which the field is lightly compacted and ir

  19. The investigation of effect of organic carbon sources addition in anaerobic-aerobic (low dissolved oxygen) sequencing batch reactor for nutrients removal from wastewaters.

    Science.gov (United States)

    Zheng, Xiong; Tong, Juan; Li, Hongjing; Chen, Yinguang

    2009-05-01

    The effect of addition of organic carbon sources (acetic acid and waste activated sludge alkaline fermentation liquid) on anaerobic-aerobic (low dissolved oxygen, 0.15-0.45 mg/L) biological municipal wastewater treatment was investigated. The results showed that carbon source addition affected not only the transformations of polyhydroxyalkanoates (PHA), glycogen, nitrogen and phosphorus, but the net removal of nitrogen and phosphorus. The removal efficiencies of TN and TP were, respectively, 61% and 61% without organic carbon source addition, 81% and 95% with acetic acid addition, and 83% and 97% with waste activated sludge alkaline fermentation liquid addition. It seems that the alkaline fermentation liquid of waste biosolids generated in biological wastewater treatment plant can be used to replace acetic acid as an additional carbon source to improve the anaerobic-aerobic (low dissolved oxygen) municipal wastewater nutrients removal although its use was observed to cause a slight increase of effluent BOD and COD concentrations.

  20. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye

    2003-01-01

    by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change......-rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

  1. Effects of elevated CO2 concentrations on soil microbial respiration and root/rhizosphere respiration in-forest soils

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The two main components of soil respiration,i.e.,root/rhizosphere and microbial respiration,respond differently to elevated atmospheric CO2 concentrations both in mechanism and sensitivity because they have different substrates derived from plant and soil organic matter,respectively.To model the carbon cycle and predict the carbon source/sink of forest ecosystems,we must first understand the relative contributions of root/rhizosphere and microbial respiration to total soil respiration under elevated CO2 concentrations.Root/rhizosphere and soil microbial respiration have been shown to increase,decrease and remain unchanged under elevated CO2 concentrations.A significantly positive relationship between root biomass and root/rhizosphere respiration has been found.Fine roots respond more strongly to elevated CO2 concentrations than coarse roots.Evidence suggests that soil microbial respiration is highly variable and uncertain under elevated CO2 concentrations.Microbial biomass and activity are related or unrelated to rates of microbial respiration.Because substrate availability drives microbial metabolism in soils,it is likely that much of the variability in microbial respiration results from differences in the response of root growth to elevated CO2 concentrations and subsequent changes in substrate production.Biotic and abiotic factors affecting soil respiration were found to affect both root/rhizosphere and microbial respiration.

  2. Effect of chlorate, molybdate, and shikimic acid on Salmonella enterica serovar Typhimurium in aerobic and anaerobic cultures.

    Science.gov (United States)

    Oliver, Christy E; Beier, Ross C; Hume, Michael E; Horrocks, Shane M; Casey, Thomas A; Caton, Joel S; Nisbet, David J; Smith, David J; Krueger, Nathan A; Anderson, Robin C

    2010-04-01

    Experiments were conducted to determine factors that affect sensitivity of Salmonella enterica serovar Typhimurium to sodium chlorate (5mM). In our first experiment, cultures grown without chlorate grew more rapidly than those with chlorate. An extended lag before logarithmic growth was observed in anaerobic but not aerobic cultures containing chlorate. Chlorate inhibition of growth during aerobic culture began later than that observed in anaerobic cultures but persisted once inhibition was apparent. Conversely, anaerobic cultures appeared to adapt to chlorate after approximately 10h of incubation, exhibiting rapid compensatory growth. In anaerobic chlorate-containing cultures, 20% of total viable counts were resistant to chlorate by 6h and had propagated to 100% resistance (>10(9)CFU mL(-1)) by 24h. In the aerobic chlorate-containing cultures, 12.9% of colonies had detectable resistance to chlorate by 6h, but only 1% retained detectable resistance at 24h, likely because these cultures had opportunity to respire on oxygen and were thus not enriched via the selective pressure of chlorate. In another study, treatment with shikimic acid (0.34 mM), molybdate (1mM) or their combination had little effect on aerobic or anaerobic growth of Salmonella in the absence of added chlorate. As observed in our earlier study, chlorate resistance was not detected in any cultures without added chlorate. Chlorate resistant Salmonella were recovered at equivalent numbers regardless of treatment after 8h of aerobic or anaerobic culture with added chlorate; however, by 24h incubation chlorate sensitivity was completely restored to aerobic but not anaerobic cultures treated with shikimic acid or molybdate but not their combination. Results indicate that anaerobic adaptation of S. Typhimurium to sodium chlorate during pure culture is likely due to the selective propagation of low numbers of cells exhibiting spontaneous resistance to chlorate and this resistance is not reversible by

  3. Cassava Stillage Treatment by Thermophilic Anaerobic Continuously Stirred Tank Reactor (CSTR)

    Science.gov (United States)

    Luo, Gang; Xie, Li; Zou, Zhonghai; Zhou, Qi

    2010-11-01

    This paper assesses the performance of a thermophilic anaerobic Continuously Stirred Tank Reactor (CSTR) in the treatment of cassava stillage under various organic loading rates (OLRs) without suspended solids (SS) separation. The reactor was seeded with mesophilic anaerobic granular sludge, and the OLR increased by increments to 13.80 kg COD/m3/d (HRT 5d) over 80 days. Total COD removal efficiency remained stable at 90%, with biogas production at 18 L/d (60% methane). Increase in the OLR to 19.30 kg COD/m3/d (HRT 3d), however, led to a decrease in TCOD removal efficiency to 79% due to accumulation of suspended solids and incomplete degradation after shortened retention time. Reactor performance subsequently increased after OLR reduction. Alkalinity, VFA and pH levels were not significantly affected by OLR variation, indicating that no additional alkaline or pH adjustment is required. More than half of the SS in the cassava stillage could be digested in the process when HRT was 5 days, which demonstrated the suitability of anaerobic treatment of cassava stillage without SS separation.

  4. Biologic treatment of wastewater from cassava flour production using vertical anaerobic baffled reactor (VABR

    Directory of Open Access Journals (Sweden)

    Gleyce T Correia

    2008-08-01

    Full Text Available The estimate cassava production in Brazil in 2007 was of 25 million tons (= 15% of the world production and most of it is used in the production of flour. During its processing, waste that can cause environmental inequality is generated, if discharged inappropriately. One of the liquid waste generated, manipueira, is characterized by its high level of organic matter. The anaerobic treatment that uses a vertical anaerobic baffled reactor (VABR inoculated with granulated sludge, is one of the ways of treating this effluent. The anaerobic biodigestion phases are separated in this kind of reactor, allowing greater stability and resistance to load shocks. The VABR was built with a width/height rate of 1:2. The pH, acidity, alkalinity, turbidity and COD removal were analyzed in 6 different regions of the reactor, which was operated with an increasing feeding from ? 2000 to ? 10000 mg COD L?¹ and HRT between 6.0 and 2.5 days. The VABR showed decreasing acidity and turbidity, an increase in alkalinity and pH, and 96% efficiency in COD removal with 3-day HRT and feeding of 3800 mg COD L?¹.

  5. Adjustment of Forest Ecosystem Root Respiration as Temperature Warms

    Institute of Scientific and Technical Information of China (English)

    Andrew J. Burton; Jerry M. Melillo; Serita D. Frey

    2008-01-01

    Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature (MAT),but the rate of this cross-ecosystem increase (Q10 = 1.6) is less than published values for short-term responses of root respiration to temperature within ecosystems (Q10 = 2-3). When specific root respiration rates and root biomass values were examined, there was a clear trend for decreasing root metabolic capacity (respiration rate at a standard temperature) with increasing MAT. There also were tradeoffs between root metabolic capacity and root system biomass, such that there were no instances of high growing season respiration rates and high root biomass occurring together. We also examined specific root respiration rates at three soil warming experiments at Harvard Forest, USA, and found decreases in metabolic capacity for roots from the heated plots. This decline could be due to either physiological acclimation or to the effects of co-occurring drier soils on the measurement date. Regardless of the cause, these findings clearly suggest that modeling efforts that allow root respiration to increase exponentially with temperature, with Qt0 values of 2 or more, may over-predict root contributions to ecosystem CO2 efflux for future climates and underestimate the amount of C available for other uses,including net primary productivity.

  6. Handbook of Indigenous Foods Involving Alkaline Fermentation

    NARCIS (Netherlands)

    Sarkar, P.K.; Nout, M.J.R.

    2014-01-01

    This book details the basic approaches of alkaline fermentation, provides a brief history, and offers an overview of the subject. The book discusses the diversity of indigenous fermented foods involving an alkaline reaction, as well as the taxonomy, ecology, physiology, and genetics of predominant m

  7. Combustion, Respiration and Intermittent Exercise: A Theoretical Perspective on Oxygen Uptake and Energy Expenditure

    Science.gov (United States)

    Scott, Christopher B.

    2014-01-01

    While no doubt thought about for thousands of years, it was Antoine Lavoisier in the late 18th century who is largely credited with the first “modern” investigations of biological energy exchanges. From Lavoisier’s work with combustion and respiration a scientific trend emerges that extends to the present day: the world gains a credible working hypothesis but validity goes missing, often for some time, until later confirmed using proper measures. This theme is applied to glucose/glycogen metabolism where energy exchanges are depicted as conversion from one form to another and, transfer from one place to another made by both the anaerobic and aerobic biochemical pathways within working skeletal muscle, and the hypothetical quantification of these components as part of an oxygen (O2) uptake measurement. The anaerobic and aerobic energy exchange components of metabolism are represented by two different interpretations of O2 uptake: one that contains a glycolytic component (1 L O2 = 21.1 kJ) and one that does not (1 L O2 = 19.6 kJ). When energy exchange transfer and oxygen-related expenditures are applied separately to exercise and recovery periods, an increased energy cost for intermittent as compared to continuous exercise is hypothesized to be a direct result. PMID:24833508

  8. Combustion, Respiration and Intermittent Exercise: A Theoretical Perspective on Oxygen Uptake and Energy Expenditure

    Directory of Open Access Journals (Sweden)

    Christopher B. Scott

    2014-03-01

    Full Text Available While no doubt thought about for thousands of years, it was Antoine Lavoisier in the late 18th century who is largely credited with the first “modern” investigations of biological energy exchanges. From Lavoisier’s work with combustion and respiration a scientific trend emerges that extends to the present day: the world gains a credible working hypothesis but validity goes missing, often for some time, until later confirmed using proper measures. This theme is applied to glucose/glycogen metabolism where energy exchanges are depicted as conversion from one form to another and, transfer from one place to another made by both the anaerobic and aerobic biochemical pathways within working skeletal muscle, and the hypothetical quantification of these components as part of an oxygen (O2 uptake measurement. The anaerobic and aerobic energy exchange components of metabolism are represented by two different interpretations of O2 uptake: one that contains a glycolytic component (1 L O2 = 21.1 kJ and one that does not (1 L O2 = 19.6 kJ. When energy exchange transfer and oxygen-related expenditures are applied separately to exercise and recovery periods, an increased energy cost for intermittent as compared to continuous exercise is hypothesized to be a direct result.

  9. Merging metabolism and power: development of a novel photobioelectric device driven by photosynthesis and respiration.

    Directory of Open Access Journals (Sweden)

    Ryan J Powell

    Full Text Available Generation of renewable energy is one of the grand challenges facing our society. We present a new bio-electric technology driven by chemical gradients generated by photosynthesis and respiration. The system does not require pure cultures nor particular species as it works with the core metabolic principles that define phototrophs and heterotrophs. The biology is interfaced with electrochemistry with an alkaline aluminum oxide cell design. In field trials we show the system is robust and can work with an undefined natural microbial community. Power generated is light and photosynthesis dependent. It achieved a peak power output of 33 watts/m(2 electrode. The design is simple, low cost and works with the biological processes driving the system by removing waste products that can impede growth. This system is a new class of bio-electric device and may have practical implications for algal biofuel production and powering remote sensing devices.

  10. Alkaline pretreatment for enhancement of biogas production from banana stem and swine manure by anaerobic codigestion.

    Science.gov (United States)

    Zhang, Chengming; Li, Jihong; Liu, Chen; Liu, Xiaoling; Wang, Jianlong; Li, Shizhong; Fan, Guifang; Zhang, Lei

    2013-12-01

    The objective of this research was to propose and investigate the availability of digested banana stem (BS) to produce biogas. Squeezed BS with less moisture content was used for biogas production through a combination of NaOH pretreatment, solid-state fermentation, and codigestion technologies. NaOH doses were optimized according to biogas fermentation performance, and the best dose was 6% (by weight) based on the total solid (TS) of BS. Under this condition, the lignin, cellulose, and hemicellulose contents decreased from 18.36%, 32.36% and 14.6% to 17.10%, 30.07%, and 10.65%, respectively, after pretreatment. After biogas digestion, TS and volatile solid (VS) reductions of the codigestion were 48.5% and 70.4%, respectively, and the biogas and methane yields based on VS loading were 357.9 and 232.4 mL/g, which were 12.1% and 21.4%, respectively, higher than the control. Results indicated that the proposed process could be an effective method for using BS to produce biogas.

  11. Treating leachate mixture with anaerobic ammonium oxidation technology

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-guo; ZHOU Shao-qi

    2006-01-01

    Large amounts of ammonium and a low content of biodegradable chemical oxygen demand(COD) are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment.Treatment effect of anaerobic ammonium oxidation (anammox) process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%,74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. The demand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the influent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.

  12. Tillage Effects on Soil Properties & Respiration

    Science.gov (United States)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  13. Catalase (KatA plays a role in protection against anaerobic nitric oxide in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Shengchang Su

    Full Text Available Pseudomonas aeruginosa (PA is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2, a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ΔnirS produced ∼50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ΔkatA mutant and a mucoid mucA22 ΔkatA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC, indicators of NO stress, were increased significantly in the ΔkatA mutant, and dramatically in a ΔnorCB mutant compared to basal levels of DNIC in PAO1 and ΔnirS mutant. Expression of KatA dramatically reduced the DNIC levels in ΔnorCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ∼6 μM. Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic

  14. Exposure to elevated temperature and Pco(2) reduces respiration rate and energy status in the periwinkle Littorina littorea.

    Science.gov (United States)

    Melatunan, Sedercor; Calosi, Piero; Rundle, Simon D; Moody, A John; Widdicombe, Stephen

    2011-01-01

    In the future, marine organisms will face the challenge of coping with multiple environmental changes associated with increased levels of atmospheric Pco(2), such as ocean warming and acidification. To predict how organisms may or may not meet these challenges, an in-depth understanding of the physiological and biochemical mechanisms underpinning organismal responses to climate change is needed. Here, we investigate the effects of elevated Pco(2) and temperature on the whole-organism and cellular physiology of the periwinkle Littorina littorea. Metabolic rates (measured as respiration rates), adenylate energy nucleotide concentrations and indexes, and end-product metabolite concentrations were measured. Compared with values for control conditions, snails decreased their respiration rate by 31% in response to elevated Pco(2) and by 15% in response to a combination of increased Pco(2) and temperature. Decreased respiration rates were associated with metabolic reduction and an increase in end-product metabolites in acidified treatments, indicating an increased reliance on anaerobic metabolism. There was also an interactive effect of elevated Pco(2) and temperature on total adenylate nucleotides, which was apparently compensated for by the maintenance of adenylate energy charge via AMP deaminase activity. Our findings suggest that marine intertidal organisms are likely to exhibit complex physiological responses to future environmental drivers, with likely negative effects on growth, population dynamics, and, ultimately, ecosystem processes.

  15. Association of alkaline phosphatase phenotypes with arthritides

    Directory of Open Access Journals (Sweden)

    Padmini A

    2004-01-01

    Full Text Available Arthritides, a symmetrical polyarticular disease of the bone are a heterogenous group of disorders in which hereditary and environmental factors in combination with an altered immune response appear to play a causative and pathogenic role in its occurrence. Alkaline phosphatase (ALP is an enzyme found in all tissues, with particularly high concentrations of ALP observed in the liver, bile ducts, placenta, and bone.Alkaline phosphatase is an orthophosphoric monoester phosphohydrolase catalyzing the hydrolysis of organic esters at alkaline pH, indicating that alkaline phosphatase is involved in fundamental biological processes.1 The present study envisages on identifying the specific electromorphic association of alkaline phosphatase with arthritides. Phenotyping of serum samples was carried out by PAGE (Polyacrylamide gel electrophoresis following Davies (19642 protocol on 41 juvenile arthritis, 150 rheumatoid arthritis and 100 osteo arthritis apart from, 25 normal children and 100 adult healthy subjects. Phenotyping of alkaline phosphatase revealed an increase in preponderance of p+ and p++ phenotypes in juvenile, rheumatoid and osteo arthritic patients. However a significant association of these phenotypes was observed only with rheumatoid arthritis condition (c2:17.46. Similarly, a significant increase of p+ phenotypes in female rheumatoid arthritis patients was observed (c2:14.973, suggesting that the decrease in p° (tissue non specific synthesis/secretion of alkaline phosphatase could be associated with decreased mineralization and ossification process in arthritis condition.

  16. Alkaline solution neutralization capacity of soil.

    Science.gov (United States)

    Asakura, Hiroshi; Sakanakura, Hirofumi; Matsuto, Toshihiko

    2010-10-01

    Alkaline eluate from municipal solid waste (MSW) incineration residue deposited in landfill alkalizes waste and soil layers. From the viewpoint of accelerating stability and preventing heavy metal elution, pH of the landfill layer (waste and daily cover soil) should be controlled. On the other hand, pH of leachate from existing MSW landfill sites is usually approximately neutral. One of the reasons is that daily cover soil can neutralize alkaline solution containing Ca(2+) as cation. However, in landfill layer where various types of wastes and reactions should be taken into consideration, the ability to neutralize alkaline solutions other than Ca(OH)(2) by soil should be evaluated. In this study, the neutralization capacities of various types of soils were measured using Ca(OH)(2) and NaOH solutions. Each soil used in this study showed approximately the same capacity to neutralize both alkaline solutions of Ca(OH)(2) and NaOH. The cation exchange capacity was less than 30% of the maximum alkali neutralization capacity obtained by the titration test. The mechanism of neutralization by the pH-dependent charge can explain the same neutralization capacities of the soils. Although further investigation on the neutralization capacity of the soils for alkaline substances other than NaOH is required, daily cover soil could serve as a buffer zone for alkaline leachates containing Ca(OH)(2) or other alkaline substances.

  17. [The development of a respiration and temperature monitor].

    Science.gov (United States)

    Du, X; Wu, B; Liu, Y; He, Q; Xiao, J

    2001-12-01

    This paper introduces the design of a monitoring system to measure the respiration and temperature of a body with an 8Xc196 single-chip microcomputer. This system can measure and display the respiration wave, respiration frequency and the body temperature in real-time with a liquid crystal display (LCD) and give an alarm when the parameters are beyond the normal scope. In addition, this device can provide a 24 hours trend graph of the respiration frequency and the body temperature parameters measured. Data can also be exchanged through serial communication interfaces (RS232) between the PC and the monitor.

  18. Autotrophic and heterotrophic components of soil respiration in permafrost zone.

    Science.gov (United States)

    Udovenko, Maria; Goncharova, Olga

    2016-04-01

    Soil carbon dioxide emissions production is an important integral indicator of soil biological activity and it includes several components: the root respiration and microbial decomposition of organic matter. Separate determination of the components of soil respiration is necessary for studying the balance of carbon in the soil and to assessment its potential as a sink or source of carbon dioxide. The aim of this study was testing field methods of separate determination of root and microbial respiration in soils of north of West Siberia. The research took place near the town Nadym, Yamalo-Nenets Autonomous District (north of West Siberia).The study area was located in the northern taiga with sporadic permafrost. Investigations were carried out at two sites: in forest and in frozen peatland. 3 methods were tested for the separation of microbial and root respiration. 1) "Shading"; 2) "Clipping"(removing the above-ground green plant parts); 3)a modified method of roots exclusion (It is to compare the emission of soils of "peat spots", devoid of vegetation and roots, and soils located in close proximity to the spots on which there is herbaceous vegetation and moss). For the experiments on methods of "Shading" and "Clipping" in the forest and on the frozen peatland ware established 12 plots, 1 x 1 m (3 plots in the forest and at 9 plots on frozen peatland; 4 of them - control).The criterions for choosing location sites were the similarity of meso- and microrelief, the same depth of permafrost, the same vegetation. Measurement of carbon dioxide emissions (chamber method) was carried out once a day, in the evening, for a week. Separation the root and microbial respiration by "Shading" showed that in the forest the root respiration contribution is 5%, and microbial - 95%. On peatlands root respiration is 41%, 59% of the microbial. In the experiment "Clipping" in peatlands root respiration is 56%, the microbial respiration - 44%, in forest- root respiration is 17%, and

  19. A survey of respirators usage for airborne chemicals in Korea.

    Science.gov (United States)

    Han, Don-Hee; Kang, Min-Sun

    2009-10-01

    A questionnaire survey was undertaken to identify the current status of respirator usage in manufacturing work environments subject to gas/vapor chemicals exposure in Korea and to suggest improvements to enhance the effectiveness of respirator usage. The number of target companies included 17 big companies, 110 small & mid-size companies, and 5 foreign companies, and the number of respondents included 601 workers and 69 persons in charge of respirators (PCR). The results explained clearly that respirator programs in practice were extremely poor in small & mid-sized companies. The findings indicated that the selection of respirators was not appropriate. Quarter mask including filtering facepiece was the most common facepiece form for respirator and was worn by sixty-four percent. Not a little proportion of respondents (33%) complained about the fit: faceseal leakage between the face and facepiece. A filtering facepiece with carbon fiber filter was used as a substitution for a gas/vapor respirator. Another result was that the PCR respondents' perception of the administration of respirators was very low. The results of this survey suggest that regal enforcement of respiratory protection programs should be established in Korea. On the basis of these findings, respiratory protection programs should include respirator selection, maintenance, training, and fit testing.

  20. Simple and convenient method for culturing anaerobic bacteria.

    OpenAIRE

    Behbehani, M J; Jordan, H. V.; Santoro, D L

    1982-01-01

    A simple and convenient method for culturing anaerobic bacteria is described. Cultures can be grown in commercially available flasks normally used for preparation of sterile external solutions. A special disposable rubber flask closure maintains anaerobic conditions in the flask after autoclaving. Growth of a variety of anaerobic oral bacteria was comparable to that obtained after anaerobic incubation of broth cultures in Brewer Anaerobic Jars.

  1. Central cholinergic regulation of respiration: nicotinic receptors

    Institute of Scientific and Technical Information of China (English)

    Xuesi M SHAO; Jack L FELDMAN

    2009-01-01

    Nicotinic acetylcholine receptors (nAChRs) are expressed in brainstem and spinal cord regions involved in the control of breathing. These receptors mediate central cholinergic regulation of respiration and effects of the exogenous ligand nicotine on respiratory pattern. Activation of a4* nAChRs in the preBotzinger Complex (preBotC), an essential site for normal respiratory rhythm generation in mammals, modulates excitatory glutamatergic neurotransmission and depolarizes preBotC inspiratory neurons, leading to increases in respiratory frequency. nAChRs are also present in motor nuclei innervating respiratory muscles. Activation of post- and/or extra-synaptic a4* nAChRs on hypoglossal (XII) motoneurons depolarizes these neurons, potentiating tonic and respiratory-related rhythmic activity. As perinatal nicotine exposure may contribute to the pathogenesis of sudden infant death syndrome (SIDS), we discuss the effects of perinatal nicotine exposure on development of the cholinergic and other neurotransmitter systems involved in control of breathing. Advances in understanding of the mechanisms underlying central cholinergic/nicotinic modulation of respiration provide a pharmacological basis for exploiting nAChRs as therapeutic targets for neurological disorders related to neural control of breathing such as sleep apnea and SIDS.

  2. Underwater breathing: the mechanics of plastron respiration

    Science.gov (United States)

    Flynn, M. R.; Bush, John W. M.

    The rough, hairy surfaces of many insects and spiders serve to render them water-repellent; consequently, when submerged, many are able to survive by virtue of a thin air layer trapped along their exteriors. The diffusion of dissolved oxygen from the ambient water may allow this layer to function as a respiratory bubble or , and so enable certain species to remain underwater indefinitely. Maintenance of the plastron requires that the curvature pressure balance the pressure difference between the plastron and ambient. Moreover, viable plastrons must be of sufficient area to accommodate the interfacial exchange of O2 and CO2 necessary to meet metabolic demands. By coupling the bubble mechanics, surface and gas-phase chemistry, we enumerate criteria for plastron viability and thereby deduce the range of environmental conditions and dive depths over which plastron breathers can survive. The influence of an external flow on plastron breathing is also examined. Dynamic pressure may become significant for respiration in fast-flowing, shallow and well-aerated streams. Moreover, flow effects are generally significant because they sharpen chemical gradients and so enhance mass transfer across the plastron interface. Modelling this process provides a rationale for the ventilation movements documented in the biology literature, whereby arthropods enhance plastron respiration by flapping their limbs or antennae. Biomimetic implications of our results are discussed.

  3. Anaerobic digestion of thin stillage for energy recovery and water reuse in corn-ethanol plants.

    Science.gov (United States)

    Alkan-Ozkaynak, A; Karthikeyan, K G

    2011-11-01

    Recycling of anaerobically-digested thin stillage within a corn-ethanol plant may result in the accumulation of nutrients of environmental concern in animal feed coproducts and inhibitory organic materials in the fermentation tank. Our focus is on anaerobic digestion of treated (centrifugation and lime addition) thin stillage. Suitability of digestate from anaerobic treatment for reuse as process water was also investigated. Experiments conducted at various inoculum-to-substrate ratios (ISRs) revealed that alkalinity is a critical parameter limiting digestibility of thin stillage. An ISR level of 2 appeared optimal based on high biogas production level (763 mL biogas/g volatile solids added) and organic matter removal (80.6% COD removal). The digester supernatant at this ISR level was found to contain both organic and inorganic constituents at levels that would cause no inhibition to ethanol fermentation. Anaerobic digestion of treated-thin stillage can be expected to improve the water and energy efficiencies of dry grind corn-ethanol plants.

  4. Can we distinguish autotrophic respiration from heterotrophic respiration in a field site using high temporal resolution CO2 flux measurements?

    Science.gov (United States)

    Biro, Beatrice; Berger, Sina; Praetzel, Leandra; Blodau, Christian

    2016-04-01

    The processes behind C-cycling in peatlands are important to understand for assessing the vulnerability of peatlands as carbon sinks under changing climate conditions. Especially boreal peatlands are likely to underlie strong alterations in the future. It is expected that C-pools that are directly influenced by vegetation and water table fluctuations can be easily destabilized. The CO2 efflux through respiration underlies autotrophic and heterotrophic processes that show different feedbacks on changing environmental conditions. In order to understand the respiration fluxes better for more accurate modelling and prognoses, the determination of the relative importance of different respiration sources is necessary. Earlier studies used e.g. exfoliation experiments, incubation experiments or modelling approaches to estimate the different respiration sources for the total ecosystem respiration (Reco). To further the understanding in this topic, I want to distinguish autotrophic and heterotrophic respiration using high temporal resolution measurements. The study site was selected along a hydrological gradient in a peatland in southern Ontario (Canada) and measurements were conducted from May to September 2015 once per month. Environmental controls (water table, soil temperature and soil moisture) that effect the respiration sources were recorded. In my study I used a Li-COR 6400XT and a Los Gatos greenhouse gas analyzer (GGA). Reco was determined by chamber flux measurements with the GGA, while simultaneously CO2 respiration measurements on different vegetation compartments like roots, leaves and mosses were conducted using the Li-COR 6400XT. The difference between Reco and autotrophic respiration equals heterotrophic respiration. After the measurements, the vegetation plots were harvested and separated for all compartments (leaves, roots, mosses, soil organic matter), dried and weighed. The weighted respiration rates from all vegetation compartments sum up to

  5. The contribution of root respiration of Pinus koraiensis seedlings to total soil respiration under elevated CO2 concentrations

    Institute of Scientific and Technical Information of China (English)

    LIUYing; HANShi-jie; LIXue-feng; ZHOUYu-mei; ZHANGJun-hui; JIAXia

    2004-01-01

    The impacts of elevated atmospheric CO2 concentrations (500 IJmol.mol-land 700 μmol.mo1-1) on total soil respiration and the contribution of root respiration of Pinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO2, the total soil respiration and roots respiration of Pinus koraiensis seedlings were measured by a LI-6400-09 soil CO2 flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil instantaneously to terminate the supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration. Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively. The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on June 16, the maximum of soil temperature at depth of 5 cm laggedb ehind that of air temperature, no differences in temperature between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 μmol .m-2.s-1, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8. respectivelv.

  6. Characterization of wheat straw-degrading anaerobic alkali-tolerant mixed cultures from soda lake sediments by molecular and cultivation techniques.

    Science.gov (United States)

    Porsch, Katharina; Wirth, Balázs; Tóth, Erika M; Schattenberg, Florian; Nikolausz, Marcell

    2015-09-01

    Alkaline pretreatment has the potential to enhance the anaerobic digestion of lignocellulosic biomass to biogas. However, the elevated pH of the substrate may require alkalitolerant microbial communities for an effective digestion. Three mixed anaerobic lignocellulolytic cultures were enriched from sediments from two soda lakes with wheat straw as substrate under alkaline (pH 9) mesophilic (37°C) and thermophilic (55°C) conditions. The gas production of the three cultures ceased after 4 to 5 weeks, and the produced gas was composed of carbon dioxide and methane. The main liquid intermediates were acetate and propionate. The physiological behavior of the cultures was stable even after several transfers. The enrichment process was also followed by molecular fingerprinting (terminal restriction fragment length polymorphism) of the bacterial 16S rRNA gene and of the mcrA/mrtA functional gene for methanogens. The main shift in the microbial community composition occurred between the sediment samples and the first enrichment, whereas the structure was stable in the following transfers. The bacterial communities mainly consisted of Sphingobacteriales, Clostridiales and Spirochaeta, but differed at genus level. Methanothermobacter and Methanosarcina genera and the order Methanomicrobiales were predominant methanogenes in the obtained cultures. Additionally, single cellulolytic microorganisms were isolated from enrichment cultures and identified as members of the alkaliphilic or alkalitolerant genera. The results show that anaerobic alkaline habitats harbor diverse microbial communities, which can degrade lignocellulose effectively and are therefore a potential resource for improving anaerobic digestion.

  7. Reverse Methanogenesis and Respiration in Methanotrophic Archaea

    Science.gov (United States)

    Koehorst, Jasper J.; Jetten, Mike S. M.; Stams, Alfons J. M.

    2017-01-01

    Anaerobic oxidation of methane (AOM) is catalyzed by anaerobic methane-oxidizing archaea (ANME) via a reverse and modified methanogenesis pathway. Methanogens can also reverse the methanogenesis pathway to oxidize methane, but only during net methane production (i.e., “trace methane oxidation”). In turn, ANME can produce methane, but only during net methane oxidation (i.e., enzymatic back flux). Net AOM is exergonic when coupled to an external electron acceptor such as sulfate (ANME-1, ANME-2abc, and ANME-3), nitrate (ANME-2d), or metal (oxides). In this review, the reversibility of the methanogenesis pathway and essential differences between ANME and methanogens are described by combining published information with domain based (meta)genome comparison of archaeal methanotrophs and selected archaea. These differences include abundances and special structure of methyl coenzyme M reductase and of multiheme cytochromes and the presence of menaquinones or methanophenazines. ANME-2a and ANME-2d can use electron acceptors other than sulfate or nitrate for AOM, respectively. Environmental studies suggest that ANME-2d are also involved in sulfate-dependent AOM. ANME-1 seem to use a different mechanism for disposal of electrons and possibly are less versatile in electron acceptors use than ANME-2. Future research will shed light on the molecular basis of reversal of the methanogenic pathway and electron transfer in different ANME types. PMID:28154498

  8. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter;

    2003-01-01

    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  9. Anaerobic digestion of kitchen wastes in a single-phased anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; HE Zheng-guang; ZHANG Li-li; XU Jian-bo; SHI Hong-zhuan; CAI Wei-min

    2005-01-01

    The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2. The ASBR was operated at four chemical oxygen demand(COD) loading rates, 2.8,respectively. The operation of the reactor with gas-phased absorb of CO2 was stable in spite of the low pH (2.6-3.9) and high concentration of TS(142 g/L) of input mixture. The output volatile fatty acid(VFA) concentration was between 2.7-4.7 g/L and had no inhibition on the methanogenic microorganism. The reactor without gas-phased absorb of CO2 became acidified when the total COD alkaline will be required to keep pH in the appropriate range for the methanogenic microorganism based on theoretical calculation. Gasphased absorb of CO2 effectively reduced the alkaline consumption, hence avoided excessive cation into the reactor.

  10. Evaluation of a prereduced anaerobically sterilized medium (PRAS II) system for identification anaerobic microorganisms.

    Science.gov (United States)

    Beaucage, C M; Onderdonk, A B

    1982-09-01

    A prereduced, anaerobically sterilized system of tubed media (PRAS II; Scott Laboratories, Fiskeville, R.I.) was evaluated for accuracy in the identification of anerobic microorganisms. PRAS II was found to be a rapid and accurate identification system for obligate anaerobes which does not require the use of gas cannula inoculation or incubation in a special anaerobic environment.

  11. Evaluation of a prereduced anaerobically sterilized medium (PRAS II) system for identification anaerobic microorganisms.

    OpenAIRE

    Beaucage, C M; Onderdonk, A B

    1982-01-01

    A prereduced, anaerobically sterilized system of tubed media (PRAS II; Scott Laboratories, Fiskeville, R.I.) was evaluated for accuracy in the identification of anerobic microorganisms. PRAS II was found to be a rapid and accurate identification system for obligate anaerobes which does not require the use of gas cannula inoculation or incubation in a special anaerobic environment.

  12. Cadmium removal by Euglena gracilis is enhanced under anaerobic growth conditions

    Energy Technology Data Exchange (ETDEWEB)

    Santiago-Martínez, M. Geovanni; Lira-Silva, Elizabeth; Encalada, Rusely; Pineda, Erika; Gallardo-Pérez, Juan Carlos [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico); Zepeda-Rodriguez, Armando [Facultad de Medicina, UNAM, Mexico City (Mexico); Moreno-Sánchez, Rafael; Saavedra, Emma [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico); Jasso-Chávez, Ricardo, E-mail: rjass_cardiol@yahoo.com.mx [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico)

    2015-05-15

    Highlights: • The protist Euglena gracilis had the ability to grow and remove large amounts of Cd{sup 2+} under anaerobic conditions. • High biomass was attained by combination of glycolytic and mitochondrial carbon sources. • Routes of degradation of glucose, glutamate and malate under anaerobic conditions in E. gracilis are described. • Biosorption was the main mechanism of Cd{sup 2+} removal in anaerobiosis, whereas the Cd{sup 2+} intracellularly accumulated was inactivated by thiol-molecules and polyphosphate. - Abstract: The facultative protist Euglena gracilis, a heavy metal hyper-accumulator, was grown under photo-heterotrophic and extreme conditions (acidic pH, anaerobiosis and with Cd{sup 2+}) and biochemically characterized. High biomass (8.5 × 10{sup 6} cells mL{sup −1}) was reached after 10 days of culture. Under anaerobiosis, photosynthetic activity built up a microaerophilic environment of 0.7% O{sub 2}, which was sufficient to allow mitochondrial respiratory activity: glutamate and malate were fully consumed, whereas 25–33% of the added glucose was consumed. In anaerobic cells, photosynthesis but not respiration was activated by Cd{sup 2+} which induced higher oxidative stress. Malondialdehyde (MDA) levels were 20 times lower in control cells under anaerobiosis than in aerobiosis, although Cd{sup 2+} induced a higher MDA production. Cd{sup 2+} stress induced increased contents of chelating thiols (cysteine, glutathione and phytochelatins) and polyphosphate. Biosorption (90%) and intracellular accumulation (30%) were the mechanisms by which anaerobic cells removed Cd{sup 2+} from medium, which was 36% higher versus aerobic cells. The present study indicated that E. gracilis has the ability to remove Cd{sup 2+} under anaerobic conditions, which might be advantageous for metal removal in sediments from polluted water bodies or bioreactors, where the O{sub 2} concentration is particularly low.

  13. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations.

    Science.gov (United States)

    Paetsch, Johannes; Kuehn, Wilfried; Six, Katharina

    2016-04-01

    Alkalinity generation in the sediment of the southern North Sea is the focus of several recent studies. One motivation for these efforts is the potentially enhanced buffering capacity of anthropogenic CO2 invasion into the corresponding pelagic system. An adaptation of a global multilayer sediment model (Heinze et al., 1999) in combination with a pelagic ecosystem model for shelf sea dynamics was used to study the benthic reactions on very different annual cycles (2001 - 2009) including the River Elbe summer flooding in 2002. The focus of this study is the efflux of alkalinity, their different contributors (aerobic respiration, denitrification, net sulfate reduction, calcite dissolution, nitrification) and their seasonal and interannual cycles. Similar to the observations covering the southern North Sea (Brenner et al., 2015) the model results show large horizontal gradients from the near-shore high productive areas with benthic remineralization up to Rmin = 10.6 mol C m-2 yr-1 and TA generation RTA = 2 mol C m-2 yr-1 to off-shore moderate productive areas with mean Rmin = 2.5 mol C m-2 yr-1 and mean TA generation RTA = 0.4 mol C m-2 yr-1. Beside calcite dissolution, aerobic respiration (producing ammonium) and denitrification are the largest contributors to alkalinity generation. Nitrification is reducing alkalinity in the sediment. Due to low regenerated primary production in summer, the year 2001 exhibits the lowest input of particulate organic matter into the sediment (POCexp=2.3 mol C m-2 yr-1), while the year 2003 exhibits the highest export production (POCexp=2.6 mol C m-2 yr-1). The biogeochemical reactions and the effluxes from the sediment follow these pelagic amplitudes with a time lag of about one year with damped amplitudes. References Brenner, H., Braeckman, U., Le Guitton, M., Meysman, F.J.R., 2015. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea. Biogeosiences Discussion, 12(15): 12395-12453. Heinze, C

  14. Impact of pretreatment on solid state anaerobic digestion of yard waste for biogas production.

    Science.gov (United States)

    Zhang, Zhikai; Li, Wangliang; Zhang, Guangyi; Xu, Guangwen

    2014-02-01

    Solid state anaerobic digestion, as a safe and environment-friendly technology to dispose municipal solid wastes, can produce methane and reduce the volume of wastes. In order to raise the digestion efficiency, this study investigated the pretreatment of yard waste by thermal or chemical method to break down the complex lignocellulosic structure. The composition and structure of pretreated yard waste were analyzed and characterized. The results showed that the pretreatment decreased the content of cellulose and hemicelluloses in yard waste and in turn improved the hydrolysis and methanogenic processes. The thermal pretreatment sample (P1) had the highest methane yield, by increasing 88% in comparison with digesting the raw material. The maximum biogas production reached 253 mL/g volatile solids (VS). The largest substrate mass reduction was obtained by the alkaline pretreatment (P5). The VS of the alkaline-treated sample decreased about 60% in comparison with the raw material.

  15. Effects of Dietary Acid Load on Exercise Metabolism and Anaerobic Exercise Performance

    Directory of Open Access Journals (Sweden)

    Susan L. Caciano, Cynthia L. Inman, Elizabeth E. Gockel-Blessing, Edward P. Weiss

    2015-06-01

    Full Text Available Dietary acid load, quantified as the potential renal acid load (PRAL of the diet, affects systemic pH and acid-base regulation. In a previous cross-sectional study, we reported that a low dietary PRAL (i.e. alkaline promoting diet is associated with higher respiratory exchange ratio (RER values during maximal exercise. The purpose of the present study was to confirm the previous findings with a short-term dietary intervention study. Additionally, we sought to determine if changes in PRAL affects submaximal exercise RER (as a reflection of substrate utilization and anaerobic exercise performance. Subjects underwent a graded treadmill exercise test (GXT to exhaustion and an anaerobic exercise performance test on two occasions, once after following a low-PRAL diet and on a separate occasion, after a high-PRAL diet. The diets were continued as long as needed to achieve an alkaline or acid fasted morning urine pH, respectively, with all being 4-9 days in duration. RER was measured during the GXT with indirect calorimetry. The anaerobic performance test was a running time-to-exhaustion test lasting 1-4 min. Maximal exercise RER was lower in the low-PRAL trial compared to the high-PRAL trial (1.10 ± 0.02 vs. 1.20 ± 0.05, p = 0.037. The low-PRAL diet also resulted in a 21% greater time to exhaustion during anaerobic exercise (2.56 ± 0.36 vs. 2.11 ± 0.31 sec, p = 0.044 and a strong tendency for lower RER values during submaximal exercise at 70% VO2max (0.88 ± 0.02 vs. 0.96 ± 0.04, p = 0.060. Contrary to our expectations, a short-term low-PRAL (alkaline promoting diet resulted in lower RER values during maximal-intensity exercise. However, the low-PRAL diet also increased anaerobic exercise time to exhaustion and appears to have shifted submaximal exercise substrate utilization to favor lipid oxidation and spare carbohydrate, both of which would be considered favorable effects in the context of exercise performance.

  16. Lymphocyte respiration in children with Trisomy 21

    Directory of Open Access Journals (Sweden)

    Aburawi Elhadi H

    2012-12-01

    Full Text Available Abstract Background This study measured lymphocyte mitochondrial O2 consumption (cellular respiration in children with trisomy 21. Methods Peripheral blood mononuclear cells were isolated from whole blood of trisomy 21 and control children and these cells were immediately used to measure cellular respiration rate. [O2] was determined as a function of time from the phosphorescence decay rates (1/τ of Pd (II-meso-tetra-(4-sulfonatophenyl-tetrabenzoporphyrin. In sealed vials containing lymphocytes and glucose as a respiratory substrate, [O2] declined linearly with time, confirming the zero-order kinetics of O2 conversion to H2O by cytochrome oxidase. The rate of respiration (k, in μM O2 min-1, thus, was the negative of the slope of [O2] vs. time. Cyanide inhibited O2 consumption, confirming that oxidation occurred in the mitochondrial respiratory chain. Results For control children (age = 8.8 ± 5.6 years, n = 26, the mean (± SD value of kc (in μM O2 per min per 107 cells was 1.36 ± 0.79 (coefficient of variation, Cv = 58%; median = 1.17; range = 0.60 to 3.12; -2SD = 0.61. For children with trisomy 21 (age = 7.2 ± 4.6 years, n = 26, the values of kc were 0.82 ± 0.62 (Cv = 76%; median = 0.60; range = 0.20 to 2.80, pp6.1 mU/L. Fourteen of 26 (54% children with trisomy 21 had kc values of 0.20 to 0.60 (i.e., kc positively correlated with body-mass index (BMI, R >0.302, serum creatinine (R >0.507, blood urea nitrogen (BUN, R >0.535 and albumin (R >0.446. Conclusions Children with trisomy 21 in this study have reduced lymphocyte bioenergetics. The clinical importance of this finding requires further studies.

  17. Observing Mean Annual Mediterranean Maquis Ecosystem Respiration

    Science.gov (United States)

    Marras, S.; Bellucco, V.; Mereu, S.; Sirca, C.; Spano, D.

    2014-12-01

    In semi arid ecosystems, extremely low Soil Water Content (SWC) values may limit ecosystem respiration (Reco) to the point of hiding the typical exponential response of respiration to temperature. This work is aimed to understand and model the Reco of an evergreen Mediterranean maquis ecosystem and to estimate the contribution of soil CO2 efflux to Reco. The selected site is located in the center of the Mediterranean sea in Sardinia (Italy). Mean annual precipitation is 588 mm and mean annual temperature is 15.9 °C. Vegetation cover is heterogeneous: 70% covered by shrubs and 30% of bare soil. Net Ecosystem Exchange (NEE) is monitored with an Eddy Covariance (EC) tower since April 2004. Soil collars were placed underneath the dominant species (Juniperus phoenicea and Pistacia lentiscus) and over the bare soil. Soil CO2 efflux was measured once a month since April 2012. Soil temperature and SWC were monitored continuously at 5 cm depth in 4 different positions close to the soil collars. Six years of EC measurements (2005-2010) and two years of soil CO2 efflux (2012-2013) measurements were analysed. Reco was estimated from the measured EC fluxes at night after filtering for adequate turbulence (u* > 1.5). Reco measurements were then binned into 1°C intervals and median values were first fitted using the Locally Estimated Scatterplot Smoothing (LOESS) method (to determine the dominant trend of the experimental curve) Reco shows an exponential increase with air and soil temperature, until SWC measured at 0.2 m depth remains above 19% vol. Secondly, the coefficients of the selected Lloyd and Taylor (1994) were estimated through the nonlinear least square (nls) method: Rref (ecosystem respiration rate at a reference temperature of 10 °C was equal to 1.65 μmol m-2 s-1 and E0 (activation energy parameter that determines the temperature sensitivity) was equal to 322.46. In addition, bare and drier soils show a reduced response of measured CO2 efflux to increasing

  18. Simulation of Human Respiration with Breathing Thermal Manikin

    DEFF Research Database (Denmark)

    Bjørn, Erik

    The human respiration contains carbon dioxide, bioeffluents, and perhaps virus or bacteria. People may also indulge in activities that produce contaminants, as for example tobacco smoking. For these reasons, the human respiration remains one of the main contributors to contamination of the indoor...

  19. Soil Respiration and Student Inquiry: A Perfect Match

    Science.gov (United States)

    Hoyt, Catherine Marie; Wallenstein, Matthew David

    2011-01-01

    This activity explores the cycling of carbon between the atmosphere (primarily as CO[subscript 2]) and biomass in plants, animals, and microscopic organisms. Students design soil respiration experiments using a protocol that resembles current practice in soil ecology. Three methods for measuring soil respiration are presented. Student-derived…

  20. Effect of Hyperglycemia on Mitochondrial Respiration in Type 2 Diabetes

    DEFF Research Database (Denmark)

    Rabøl, Rasmus; Højberg, Patricia M V; Almdal, Thomas;

    2009-01-01

    DM. PATIENTS AND METHODS: Eleven patients with T2DM [9 males, 2 females; age, 52.8 +/- 2.5 yr (mean +/- se); body mass index, 30.2 +/- 1.1 kg/m(2)] in poor glycemic control were treated with insulin aspart and NPH insulin for a median period of 46 d (range, 31-59). Mitochondrial respiration...... glucose (12.7 +/- 1.1 to 6.5 +/- 0.3 mmol/liter; P respiration per milligram muscle was lower in T2DM compared to controls [substrates for complex I, 24% lower (P respiration...... and citrate synthase activity did not differ before and after improvements in glycemic control, but mitochondrial respiration correlated with fasting plasma glucose before (r(2) = 0.53; P respiration normalized...

  1. Redefinition and global estimation of basal ecosystem respiration rate

    DEFF Research Database (Denmark)

    Yuan, Wenping; Luo, Yiqi; Li, Xianglan;

    2011-01-01

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still...... use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data...... use efficiency GPP model (i.e., EC-LUE) was applied to estimate global GPP, BR and ER with input data from MERRA (Modern Era Retrospective-Analysis for Research and Applications) and MODIS (Moderate resolution Imaging Spectroradiometer). The global ER was 103 Pg C yr −1, with the highest respiration...

  2. Light-enhanced oxygen respiration in benthic phototrophic communities

    DEFF Research Database (Denmark)

    Epping, EHG; Jørgensen, BB

    1996-01-01

    Two microelectrode studies demonstrate the effect of Light intensity and photosynthesis on areal oxygen respiration in a hypersaline mat at Guerrero Negro, Mexico, and in an intertidal sediment at Texel, The Netherlands. The hypersaline mat was studied in the laboratory at light intensities of 0...... light intensities. Areal respiration, calculated from the difference between areal gross and areal net photosynthesis, increased from 3.9 to 14.4 nmol O-2 cm(2) min(-1) with increasing surface irradiance. This light-enhanced areal respiration was related to an increase in oxygen penetration depth from 0.......2 to 2.0 mm, thus expanding the volume of sediment involved in oxygen respiration beneath the mat surface. The mean rate of oxygen respiration per volume of mat remained constant at a rate of similar to 100 nmol O-2 cm(-3) min(-1). Oxygen profiles for the intertidal sediment were recorded in situ during...

  3. [Alkaline phosphatase in Amoeba proteus].

    Science.gov (United States)

    Sopina, V A

    2005-01-01

    In free-living Amoeba proteus (strain B), 3 phosphatase were found after disc-electrophoresis of 10 microg of protein in PAGE and using 1-naphthyl phosphate as a substrate a pH 9.0. These phosphatases differed in their electrophoretic mobilities - "slow" (1-3 bands), "middle" (one band) and "fast" (one band). In addition to 1-naphthyl phosphate, "slow" phosphatases were able to hydrolyse 2-naphthyl phosphate and p-nitrophenyl phosphate. They were slightly activated by Mg2+, completely inhibited by 3 chelators (EDTA, EGTA and 1,10-phenanthroline), L-cysteine, sodium dodecyl sulfate and Fe2+, Zn2+ and Mn2+ (50 mM), considerably inactivated by orthovanadate, molybdate, phosphatase inhibitor cocktail 1, p-nitrophenyl phosphate, Na2HPO4, DL-dithiothreitol and urea and partly inhibited by H2O2, DL-phenylalanine, 2-mercaptoethanol, phosphatase inhibitor cocktail 2 and Ca2+. Imidazole, L-(+)-tartrate, okadaic acid, NaF and sulfhydryl reagents -p-(hydroxy-mercuri)benzoate and N-ethylmaleimide - had no influence on the activity of "slow" phosphatases. "Middle" and "fast" phosphatases, in contrast to "slow" ones, were not inactivated by 3 chelators. The "middle" phosphatase differed from the "fast" one by smaller resistance to urea, Ca2+, Mn2+, phosphates and H2O2 and greater resistance to dithiothreitol and L-(+)-tartrate. In addition, the "fast" phosphatase was inhibited by L-cysteine but the "middle" one was activated by it. Of 5 tested ions (Mg2+, Cu2+, Mn2+, Ca2+ and Zn2+), only Zn2+ reactivated "slow" phosphatases after their inactivation by EDTA treatment. The reactivation of apoenzyme was only partial (about 35 %). Thus, among phosphatases found in amoebae at pH 9.0, only "slow" ones are Zn-metalloenzymes and may be considered as alkaline phosphatases (EC 3.1.3.1). It still remains uncertain, to which particular phosphatase class "middle" and "fast" phosphatases (pH 9.0) may belong.

  4. 76 FR 3175 - Proposed Extension of Existing Information Collection; Respirator Program Records

    Science.gov (United States)

    2011-01-19

    ... Safety and Health Administration Proposed Extension of Existing Information Collection; Respirator... miners against hazards. Where protective equipment or respirators are required because of exposure to... respirators is essential for ensuring that workers are properly and effectively using the equipment. Title...

  5. Carbon monoxide conversion by anaerobic bioreactor sludges

    NARCIS (Netherlands)

    Sipma, J.; Stams, A.J.M.; Lens, P.N.L.; Lettinga, G.

    2003-01-01

    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55degreesC
    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and

  6. Anaerobic critical velocity in four swimming techniques.

    Science.gov (United States)

    Neiva, H P; Fernandes, R J; Vilas-Boas, J P

    2011-03-01

    The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities.

  7. Integrated anaerobic and aerobic treatment of sewage.

    NARCIS (Netherlands)

    Kaijun Wang,

    1994-01-01

    This thesis describes results of investigations dealing with sequential concept of anaerobic-aerobic treatment of municipal wastewater. The main purposes of the study were 1) to develop a proper anaerobic hydrolytic pretreatment unit, consisting of a Hydrolysis Upflow Sludge Bed (HUSB-) reactor and

  8. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

  9. Cadmium removal by Euglena gracilis is enhanced under anaerobic growth conditions.

    Science.gov (United States)

    Santiago-Martínez, M Geovanni; Lira-Silva, Elizabeth; Encalada, Rusely; Pineda, Erika; Gallardo-Pérez, Juan Carlos; Zepeda-Rodriguez, Armando; Moreno-Sánchez, Rafael; Saavedra, Emma; Jasso-Chávez, Ricardo

    2015-05-15

    The facultative protist Euglena gracilis, a heavy metal hyper-accumulator, was grown under photo-heterotrophic and extreme conditions (acidic pH, anaerobiosis and with Cd(2+)) and biochemically characterized. High biomass (8.5×10(6)cellsmL(-1)) was reached after 10 days of culture. Under anaerobiosis, photosynthetic activity built up a microaerophilic environment of 0.7% O₂, which was sufficient to allow mitochondrial respiratory activity: glutamate and malate were fully consumed, whereas 25-33% of the added glucose was consumed. In anaerobic cells, photosynthesis but not respiration was activated by Cd(2+) which induced higher oxidative stress. Malondialdehyde (MDA) levels were 20 times lower in control cells under anaerobiosis than in aerobiosis, although Cd(2+) induced a higher MDA production. Cd(2+) stress induced increased contents of chelating thiols (cysteine, glutathione and phytochelatins) and polyphosphate. Biosorption (90%) and intracellular accumulation (30%) were the mechanisms by which anaerobic cells removed Cd(2+) from medium, which was 36% higher versus aerobic cells. The present study indicated that E. gracilis has the ability to remove Cd(2+) under anaerobic conditions, which might be advantageous for metal removal in sediments from polluted water bodies or bioreactors, where the O₂ concentration is particularly low.

  10. Plasmodesmal-mediated cell-to-cell transport in wheat roots is modulated by anaerobic stress

    Science.gov (United States)

    Cleland, R. E.; Fujiwara, T.; Lucas, W. J.

    1994-01-01

    Cell-to-cell transport of small molecules and ions occurs in plants through plasmodesmata. Plant roots are frequently subjected to localized anaerobic stress, with a resultant decrease in ATP. In order to determine the effect of this stress on plasmodesmal transport, fluorescent dyes of increasing molecular weight (0.46 to 1OkDa) were injected into epidermal and cortical cells of 3-day-old wheat roots, and their movement into neighboring cells was determined by fluorescence microscopy. Anaerobiosis was generated by N2 gas or simulated by the presence of sodium azide, both of which reduced the ATP levels in the tissue by over 80%. In the absence of such stress, the upper limit for movement, or size exclusion limit (SEL), of cortical plasmodesmata was roots, indicating that plasmodesmata may be conduits for nucleotide (ATP and ADP) exchange between cells. Upon imposition of stress, the SEL rose to between 5 and 10 kDa. This response of plasmodesmata to a decrease in the level of ATP suggests that they are constricted by an ATP-dependent process so as to maintain a restricted SEL. When roots are subjected to anaerobic stress, an increase in SEL may permit enhanced delivery of sugars to the affected cells of the root where anaerobic respiration could regenerate the needed ATP.

  11. Prospects of Anaerobic Digestion Technology in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As the world's largest developing country, China must face the problem of managing municipal solid waste, and the challenge of organic waste disposal is even more serious. Considering the characteristics of traditional waste disposal technologies and the subsequent secondary pollution, anaerobic digestion has various advantages such as reduction in the land needed for disposal and preservation of environmental quality. In light of the energy crisis, this paper focuses on the potential production of biogas from biowaste through anaerobic digestion processes, the problems incurred by the waste collection system, and the efficiency of the anaerobic digestion process. Use of biogas in a combined heat and power cogeneration system is also discussed. Finally, the advantages of anaerobic digestion technology for the Chinese market are summarized. The anaerobic digestion is suggested to be a promising treating technology for the organic wastes in China.

  12. Toxicants inhibiting anaerobic digestion: a review.

    Science.gov (United States)

    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.

  13. Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

    Science.gov (United States)

    Kane, E.S.; Chivers, M.R.; Turetsky, M.R.; Treat, C.C.; Petersen, D.G.; Waldrop, M.; Harden, J.W.; McGuire, A.D.

    2013-01-01

    To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2 production potential at 10 cm depth (14.1 ± 0.9 μmol C g−1 d−1) was as high as aerobic CO2 production potential (10.6 ± 1.5 μmol C g−1 d−1), while CH4 production was low (mean of 7.8 ± 1.5 nmol C g−1 d−1). Denitrification enzyme activity indicated a very high denitrification potential (197 ± 23 μg N g−1 d−1), but net NO-3 reduction suggested this was a relatively minor pathway for anaerobic CO2 production. Abundances of denitrifier genes (nirK and nosZ) did not change across water table treatments. SO2-4 reduction also did not appear to be an important pathway for anaerobic CO2 production. The net accumulation of acetate and formate as decomposition end products in the raised water table treatment suggested that fermentation was a significant pathway for carbon mineralization, even in the presence of NO-3. Dissolved organic carbon (DOC) concentrations were the strongest predictors of potential anaerobic and aerobic CO2 production. Across all water table treatments, the CO2:CH4 ratio increased with initial DOC leachate concentrations. While the field water table treatment did not have a significant effect on mean CO2 or CH4 production potential, the CO2:CH4 ratio was highest in shallow peat incubations from the drained treatment. These data suggest that with continued drying or with a more variable water table, anaerobic CO2 production may be favored over CH4 production in this rich fen. Future research examining the potential for dissolved organic substances to facilitate anaerobic respiration, or alternative redox processes that limit the effectiveness of organic acids as substrates in anaerobic metabolism, would help explain additional

  14. Prophylactic treatment with alkaline phosphatase in cardiac surgery induces endogenous alkaline phosphatase release

    NARCIS (Netherlands)

    Kats, Suzanne; Brands, Ruud; Hamad, Mohamed A. Soliman; Seinen, Willem; Schamhorst, Volkher; Wulkan, Raymond W.; Schoenberger, Jacques P.; van Oeveren, Wim

    2012-01-01

    Introduction: Laboratory and clinical data have implicated endotoxin as an important factor in the inflammatory response to cardiopulmonary bypass. We assessed the effects of the administration of bovine intestinal alkaline phosphatase (bIAP), an endotoxin detoxifier, on alkaline phosphatase levels

  15. Uptake of arsenic by alkaline soils near alkaline coal fly ash disposal facilities.

    Science.gov (United States)

    Khodadoust, Amid P; Theis, Thomas L; Murarka, Ishwar P; Naithani, Pratibha; Babaeivelni, Kamel

    2013-12-01

    The attenuation of arsenic in groundwater near alkaline coal fly ash disposal facilities was evaluated by determining the uptake of arsenic from ash leachates by surrounding alkaline soils. Ten different alkaline soils near a retired coal fly ash impoundment were used in this study with pH ranging from 7.6 to 9.0, while representative coal fly ash samples from two different locations in the coal fly ash impoundment were used to produce two alkaline ash leachates with pH 7.4 and 8.2. The arsenic found in the ash leachates was present as arsenate [As(V)]. Adsorption isotherm experiments were carried out to determine the adsorption parameters required for predicting the uptake of arsenic from the ash leachates. For all soils and leachates, the adsorption of arsenic followed the Langmuir and Freundlich equations, indicative of the favorable adsorption of arsenic from leachates onto all soils. The uptake of arsenic was evaluated as a function of ash leachate characteristics and the soil components. The uptake of arsenic from alkaline ash leachates, which occurred mainly as calcium hydrogen arsenate, increased with increasing clay fraction of soil and with increasing soil organic matter of the alkaline soils. Appreciable uptake of arsenic from alkaline ash leachates with different pH and arsenic concentration was observed for the alkaline soils, thus attenuating the contamination of groundwater downstream of the retired coal fly ash impoundment.

  16. Transcriptional regulation of the outer membrane porin gene ompW reveals its physiological role during the transition from the aerobic to the anaerobic lifestyle of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Minfeng eXiao

    2016-05-01

    Full Text Available Understanding bacterial physiology relies on elucidating the regulatory mechanisms and cellular functions of those differentially expressed genes in response to environmental changes. A widespread Gram-negative bacterial outer membrane protein OmpW has been implicated in the adaptation to stresses in various species. It is recently found to be present in the regulon of the global anaerobic transcription factor FNR and ArcA in E. coli. However, little is known about the physiological implications of this regulatory disposition. In this study, we demonstrate that transcription of ompW is indeed mediated by a series of global regulators involved in the anaerobiosis of E. coli. We show that FNR can both activate and repress the expression of ompW through its direct binding to two distinctive sites, -81.5 and -126.5 bp respectively, on ompW promoter. ArcA also participates in repression of ompW under anaerobic condition, but in an FNR dependent manner. Additionally, ompW is also subject to the regulation by CRP and NarL which senses the availability and types of carbon sources and respiration electron acceptors in the environment respectively, implying a role of OmpW in the carbon and energy metabolism of E. coli during its anaerobic adaptation. Molecular docking reveals that OmpW can bind fumarate, an alternative electron acceptor in anaerobic respiration, with sufficient affinity. Moreover, supplement of fumarate or succinate which belongs to the C4-dicarboxylates family of metabolite, to E. coli culture rescues OmpW-mediated colicin S4 killing. Taken together, we propose that OmpW is involved in anaerobic carbon and energy metabolism to mediate the transition from aerobic to anaerobic lifestyle in E. coli.

  17. Molecular Characterization of Bacterial Respiration on Minerals

    Energy Technology Data Exchange (ETDEWEB)

    Blake, Robert C.

    2013-04-26

    The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength

  18. Root Zone Respiration on Hydroponically Grown Wheat Plant Systems

    Science.gov (United States)

    Soler-Crespo, R. A.; Monje, O. A.

    2010-01-01

    Root respiration is a biological phenomenon that controls plant growth and physiological development during a plant's lifespan. This process is dependent on the availability of oxygen in the system where the plant is located. In hydroponic systems, where plants are submerged in a solution containing vital nutrients but no type of soil, the availability of oxygen arises from the dissolved oxygen concentration in the solution. This oxygen concentration is dependent on the , gas-liquid interface formed on the upper surface of the liquid, as given by Henry's Law, depending on pressure and temperature conditions. Respiration rates of the plants rise as biomass and root zone increase with age. The respiration rate of Apogee wheat plants (Triticum aestivum) was measured as a function of light intensity (catalytic for photosynthesis) and CO2 concentration to determine their effect on respiration rates. To determine their effects on respiration rate and plant growth microbial communities were introduced into the system, by Innoculum. Surfactants were introduced, simulating gray-water usage in space, as another factor to determine their effect on chemical oxygen demand of microbials and on respiration rates of the plants. It is expected to see small effects from changes in CO2 concentration or light levels, and to see root respiration decrease in an exponential manner with plant age and microbial activity.

  19. Respiration and sodium transport in rabbit urinary bladder.

    Science.gov (United States)

    Silverthorn, S U; Eaton, D C

    1982-07-28

    Respiration of rabbit urinary bladder was measured in free-floating pieces and in short-circuited pieces mounted in an Ussing chamber. Ouabain, amiloride, and potassium-free saline inhibited respiration approx. 20%; sodium-free saline depressed respiration approx. 40-50%. The coupling ratio between respiration and transport in short-circuited tissues was about two sodium ions per molecule O2. Chloride-free saline depressed mean oxygen consumption 21% in free-floating tissue pieces; 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) and furosemide had no effect. The effect of chloride-free saline in short-circuited tissues was variable; in tissues with low transport rates, respiration was stimulated about 21% while in tissue with high transport rates respiration was reduced about 24%. Nystatin and monensin, both of which markedly increase the conductance of cell membranes with a concomitant increase in sodium entry, stimulated respiration. These data indicate that 50-60% of the total oxygen consumption is not influenced by sodium, 20-25% is linked to (Na+ +K+)-ATPase transport, while the remaining 25-30% is sodium-dependent but not ouabain-inhibitable.

  20. Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

    Science.gov (United States)

    Wang, Zhen; Ji, Lei; Hou, Xiangyang; Schellenberg, Michael P

    2016-01-01

    Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2).s(-1)) and clipping (2.06 μmol.m(-2).s(-1)) than under grazing (1.65 μmol.m-(2).s(-1)) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China.

  1. Alternative respiration and fumaric acid production of Rhizopus oryzae.

    Science.gov (United States)

    Gu, Shuai; Xu, Qing; Huang, He; Li, Shuang

    2014-06-01

    Under the conditions of fumaric acid fermentation, Rhizopus oryzae ME-F14 possessed at least two respiratory systems. The respiration of mycelia was partially inhibited by the cytochrome respiration inhibitor antimycin A or the alternative respiration inhibitor salicylhydroxamic acid and was completely inhibited in the presence of both antimycin A and salicylhydroxamic acid. During fumaric acid fermentation process, the activity of alternative respiration had a great correlation with fumaric acid productivity; both of them reached peak at the same time. The alternative oxidase gene, which encoded the mitochondrial alternative oxidase responsible for alternative respiration in R. oryzae ME-F14, was cloned and characterized in Escherichia coli. The activity of alternative respiration, the alternative oxidase gene transcription level, as well as the fumaric acid titer were measured under different carbon sources and different carbon-nitrogen ratios. The activity of alternative respiration was found to be comparable to the transcription level of the alternative oxidase gene and the fumaric acid titer. These results indicated that the activity of the alternative oxidase was regulated at the transcription stage under the conditions tested for R. oryzae ME-F14.

  2. Syntrophic anaerobic photosynthesis via direct interspecies electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Phuc T.; Lindemann, Stephen R.; Shi, Liang; Dohnalkova, Alice C.; Fredrickson, James K.; Madigan, Michael T.; Beyenal, Haluk

    2017-01-09

    Microbial phototrophs are key primary producers on Earth. Currently known electron donors for microbial photosynthesis include H2O, H2, H2S and other reduced inorganic compounds. We describe a new form of metabolism linking anoxygenic photosynthesis to anaerobic respiration, or “syntrophic anoxygenic photosynthesis.” We show that photoautotrophy in green sulfur bacterium Prosthecochloris aestaurii can be driven not only by electrons from a graphite electrode, but also by acetate oxidation via interspecies electron transfer from heterotrophic partner bacterium Geobacter sulfurreducens. P. aestuarii photosynthetic growth using reductant provided by either an electrode or syntrophy was robust and light-dependent. By contrast, P. aestuarii did not grow in co-culture with a G. sulfurreducens mutant lacking a trans-outer membrane porin-cytochrome protein complex required for direct intercellular electron transfer,. This syntrophic interaction suggests revisitation of global carbon cycling in anoxic environments and lays a foundation for further engineering of phototrophic microbial communities for biotechnological applications, such as waste treatment and bioenergy production.

  3. The cytological implications of primary respiration.

    Science.gov (United States)

    Crisera, P N

    2001-01-01

    Observing the macroscopic complexities of evolved species, the exceptional continuity that occurs among different cells, tissues and organs to respond coherently to the proper set of stimuli as a function of self/species survival is appreciable. Accordingly, it alludes to a central rhythm that resonates throughout the cell; nominated here as primary respiration (PR), which is capable of binding and synchronizing a diversity of physiological processes into a functional biological unity. Phylogenetically, it was conserved as an indispensable element in the makeup of the subkingdom Metazoa, since these species require a high degree of coordination among the different cells that form their body. However, it does not preclude the possibility of a basal rhythm to orchestrate the intricacies of cellular dynamics of both prokaryotic and eukaryotic cells. In all probability, PR emerges within the crucial organelles, with special emphasis on the DNA (5), and propagated and transduced within the infrastructure of the cytoskeleton as wave harmonics (49). Collectively, this equivalent vibration for the subphylum Vertebrata emanates as craniosacral respiration (CSR), though its expression is more elaborate depending on the development of the CNS. Furthermore, the author suggests that the phenomenon of PR or CSR be intimately associated to the basic rest/activity cycle (BRAC), generated by concentrically localized neurons that possess auto-oscillatory properties and assembled into a vital network (39). Historically, during Protochordate-Vertebrate transition, this area circumscribes an archaic region of the brain in which many vital biological rhythms have their source, called hindbrain rhombomeres. Bass and Baker (2) propose that pattern-generating circuits of more recent innovations, such as vocal, electromotor, extensor muscle tonicity, locomotion and the extraocular system, have their origin from the same Hox gene-specified compartments of the embryonic hindbrain (rhombomeres

  4. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes.

    Science.gov (United States)

    Melton, Emily Denise; Sorokin, Dimitry Y; Overmars, Lex; Chertkov, Olga; Clum, Alicia; Pillay, Manoj; Ivanova, Natalia; Shapiro, Nicole; Kyrpides, Nikos C; Woyke, Tanja; Lapidus, Alla L; Muyzer, Gerard

    2016-01-01

    Desulfurivibrio alkaliphilus strain AHT2(T) is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2(T) is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. D. alkaliphilus AHT2(T) is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2(T) was sequenced by the DOE Joint Genome Institute as part of the Community Science Program.

  5. Comparison of different liquid anaerobic digestion effluents as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fuqing; Shi Jian [Department of Food, Agricultural and Biological Engineering, Ohio State University, Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691 (United States); Lv Wen; Yu Zhongtang [Department of Animal Sciences, Ohio State University, Columbus, OH 43210 (United States); Li Yebo, E-mail: li.851@osu.edu [Department of Food, Agricultural and Biological Engineering, Ohio State University, Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691 (United States)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Compared methane production of solid AD inoculated with different effluents. Black-Right-Pointing-Pointer Food waste effluent (FWE) had the largest population of acetoclastic methanogens. Black-Right-Pointing-Pointer Solid AD inoculated with FWE produced the highest methane yield at F/E ratio of 4. Black-Right-Pointing-Pointer Dairy waste effluent (DWE) was rich of cellulolytic and xylanolytic bacteria. Black-Right-Pointing-Pointer Solid AD inoculated with DWE produced the highest methane yield at F/E ratio of 2. - Abstract: Effluents from three liquid anaerobic digesters, fed with municipal sewage sludge, food waste, or dairy waste, were evaluated as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover in mesophilic reactors. Three feedstock-to-effluent (F/E) ratios (i.e., 2, 4, and 6) were tested for each effluent. At an F/E ratio of 2, the reactor inoculated by dairy waste effluent achieved the highest methane yield of 238.5 L/kgVS{sub feed}, while at an F/E ratio of 4, the reactor inoculated by food waste effluent achieved the highest methane yield of 199.6 L/kgVS{sub feed}. The microbial population and chemical composition of the three effluents were substantially different. Food waste effluent had the largest population of acetoclastic methanogens, while dairy waste effluent had the largest populations of cellulolytic and xylanolytic bacteria. Dairy waste also had the highest C/N ratio of 8.5 and the highest alkalinity of 19.3 g CaCO{sub 3}/kg. The performance of solid-state batch anaerobic digestion reactors was closely related to the microbial status in the liquid anaerobic digestion effluents.

  6. Wood and foliar respiration of tropical wet forest environment

    Science.gov (United States)

    Asao, S.; Bedoya Arrieta, R.; Ryan, M. G.

    2011-12-01

    Wood and foliar respiration from tropical forests constitute major components of ecosystem respiration that may control their productivity and carbon storage. However, few estimates on tropical forests vary greatly. Furthermore, the trees in these forests respire great amounts of carbon, but impacts of individual tree species on respiration is not well known. We examined wood and foliar respiration in this environment in relation to individual tree species. The objectives of this study were to: 1) identify how respiration rates relate to scaling variables for wood and foliage, 2) examine the effects of individual tree species on these relationships, 3) extrapolate the rates to the annual fluxes of the whole stands, and 4) determine if tree species differed in these fluxes. Established on an abandoned pasture in 1988 at La Selva Biological Station in Costa Rica, the monodominant stands contained four native species in a complete randomized block design. Respiration rates based on tissue surface area ranged among dominant tree species from 0.6 to 1.0 μg C m^-2 s^-1 for small diameter wood (<10cm), 1.0 to 1.8 μg C m^-2 s^-1 for large diameter wood, and 0.7 to 0.8 μg C m^-2 s^-1 for foliage. Understory species had similar wood respiration rates, but foliage respiration rates were about half of those for canopy leaves. Among surface area, volume, or biomass, respiration rates scaled best with surface area for wood with small diameter, volume or biomass for large diameter wood, and leaf area for foliage. These relationships differed slightly among tree species and between canopy trees and understory species. Foliar respiration rate was generally related to leaf nitrogen content, and this relationship differed among dominant tree species. Temperature response of foliar respiration also differed among tree species and canopy class. However, daily and annual temperature fluctuations had less than 3% effect on annual flux. Annual respiratory fluxes from wood and foliage

  7. Estimating daytime ecosystem respiration from eddy-flux data

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Herbst, Mathias;

    2011-01-01

    To understand what governs the patterns of net ecosystem exchange of CO2, an understanding of factors influencing the component fluxes, ecosystem respiration and gross primary production is needed. In the present paper, we introduce an alternative method for estimating daytime ecosystem respiration...... based on whole ecosystem fluxes from a linear regression of photosynthetic photon flux density data vs. daytime net ecosystem exchange data at forest ecosystem level. This method is based on the principles of the Kok-method applied at leaf level for estimating daytime respiration. We demonstrate...

  8. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Directory of Open Access Journals (Sweden)

    R. Kiko

    2015-10-01

    Full Text Available Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ. At depth, the animals experience reduced temperature and oxygen partial pressure (pO2 and an increased carbon dioxide partial pressure (pCO2 compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation – a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2 does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  9. Defective mitochondrial respiration, altered dNTP pools and reduced AP endonuclease 1 activity in peripheral blood mononuclear cells of Alzheimer's disease patients

    DEFF Research Database (Denmark)

    Maynard, Scott; Hejl, Anne-Mette; Dinh, Tran Thuan Son;

    2015-01-01

    AIMS: Accurate biomarkers for early diagnosis of Alzheimer's disease (AD) are badly needed. Recent reports suggest that dysfunctional mitochondria and DNA damage are associated with AD development. In this report, we measured various cellular parameters, related to mitochondrial bioenergetics...... as possible. We measured glycolysis and mitochondrial respiration fluxes using the Seahorse Bioscience flux analyzer, mitochondrial ROS production using flow cytometry, dNTP levels by way of a DNA polymerization assay, DNA strand breaks using the Fluorometric detection of Alkaline DNA Unwinding (FADU) assay...... on adjustments for gender and/or age. CONCLUSIONS: This study reveals impaired mitochondrial respiration, altered dNTP pools and reduced DNA repair activity in PBMCs of AD patients, thus suggesting that these biochemical activities may be useful as biomarkers for AD....

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

    Directory of Open Access Journals (Sweden)

    V. Gowdaman

    2015-04-01

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

  11. Two-stage high-rate biogas (H2 and CH4) production from food waste using anaerobic mixed microflora

    Science.gov (United States)

    Xu, K.; Lee, D.; Kobayashi, T.; Ebie, Y.; Li, Y.; Inamori, Y.

    2010-12-01

    To achieve the high-rate H2 and CH4 production from food waste using fermentative anaerobic microflora, the effects of carbonate-alkalinity in the recirculated digestion sludge on continuous two-stage fermentation were investigated. Higher H2 production rate of 2.9 L-H2/L/day was achieved at the recycle ratio of 1.0 in an alkalinity range of 9000 to 10000 mg-CaCO3/L. The maximum CH4 production rate was stably maintained at the range of 1.85 to 1.88 L-CH4/L/day without alkalinity change. Carbonate alkalinity in digestion sludge could reduce the H2 partial pressure in the headspace of the fermentation reactors, and improve a biogas production capacity in the two-stage fermentation process. The average volatile solids degradation rate in the overall process increased as the digestion sludge recycle increased from 0.5 to 1.0. These results show that the alkalinity in recycle of the digestion sludge is crucial factor in determining biogas (H2 and CH4) production capacity and reducing the total solids.

  12. Some durability aspects of hybrid alkaline cements

    Directory of Open Access Journals (Sweden)

    Donatello S.

    2014-04-01

    Full Text Available Blended cements that contain a high content of fly ash and a low content of Portland cement typically suffer from low early strength development and long setting times. Recently, one method of overcoming these problems has been to use an alkali activator to enhance the reactivity of fly ash particles at early ages. Such cements can be grouped under the generic term “hybrid alkaline cements”, where both cement clinker and fly ash, encouraged by the presence of alkalis, are expected to contribute to cementitious gel formation. The work presented here examines some of the durability aspects of high fly ash content hybrid alkaline cement. Specifically, the aspects investigated were: exposure at high temperatures (up to 1000°C, resistance to immersion in aggressive solutions and susceptibility to the alkali aggregate reaction. All tests were repeated with a commercially available sulfate resistant Portland cement for comparison. When exposed to high temperatures, the hybrid alkaline cement showed strikingly different behaviour compared to the control Portland cement, showing fewer micro-cracks and maintaining residual compressive strengths at least equal to original strengths. Beyond 700°C, the hybrid alkaline cement began to sinter, which resulted in shrinkage of around 5% and a 100% increase in residual compressive strengths. No such sintering event was noted in the control Portland cement, which showed a drastic loss in residual compressive strengths upon heating. In immersion tests, the hybrid alkaline cement possessed excellent resistance to sulfate and seawater attack, similar to the control sulfate resistant cement. Both cements were however severely degraded by immersion in 0.1M HCl for 90 days. Both binders complied with the accelerated alkali-aggregate test but when this test was extended, the hybrid alkaline binder showed much greater dimensional stability. Possible reasons for the differences in durability behaviour in both cements

  13. Alkaline Capacitors Based on Nitride Nanoparticles

    Science.gov (United States)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  14. Electrochemical behaviour of alkaline copper complexes

    Indian Academy of Sciences (India)

    C L Aravinda; S M Mayanna; V R Muralidharan

    2000-10-01

    A search for non-cyanide plating baths for copper resulted in the development of alkaline copper complex baths containing trisodium citrate [TSC] and triethanolamine [TEA]. Voltammetric studies were carried out on platinum to understand the electrochemical behaviour of these complexes. In TSC solutions, the deposition of copper involves the slow formation of a monovalent species. Adsorption of this species obeys Langmuir isotherm. In TEA solutions the deposition involves the formation of monovalent ions obeying the non-activated Temkin isotherm. Conversion of divalent to monovalent copper is also slow. In TEA and TSC alkaline copper solutions, the predominant species that undergo stepwise reduction contain only TEA ligands

  15. Influence of alkalinity and VFAs on the performance of an UASB reactor with recirculation for the treatment of Tequila vinasses.

    Science.gov (United States)

    López-López, Alberto; León-Becerril, Elizabeth; Rosales-Contreras, María Elena; Villegas-García, Edgardo

    2015-01-01

    The main problem linked to the stability of upflow anaerobic sludge blanket (UASB) reactors during the treatment of Tequila vinasse is the high acidity and the null alkalinity present in this effluent. This research evaluates the effect of alkalinity and volatile fatty acids (VFAs) concentration on the performance of an UASB reactor with recirculation of the effluent for removing organic matter and biogas production from Tequila vinasses. Recirculation of the effluent reduces the impact of VFAs and organic matter concentration present in the influent, inducing the stability of the reactor. The UASB reactor was operated during 235 days at organic loading rates from 2.5 to 20.0 kg m(-3) d(-1), attaining a removal efficiency of COD greater than 75% with a methane yield of 335 ml CH4 g(-1) COD at SPT, maintaining a ratio of VFAs/Alk ≤ 0.5. Therefore, an optimal ratio of VFAs/Alk was established for the system operating in stable conditions for the treatment of Tequila vinasses. Under these conditions, the alkalinity was recuperated by the system itself, without the addition of external alkalinity.

  16. Effects of feeding, digestion and fasting on the respiration and swimming capability of juvenile sterlet sturgeon (Acipenser ruthenus, Linnaeus 1758).

    Science.gov (United States)

    Cai, Lu; Johnson, David; Fang, Min; Mandal, Prashant; Tu, Zhiying; Huang, Yingping

    2017-02-01

    The objective of this study is to provide information on changes in swimming capability and respiration of the sterlet sturgeon (Acipenser ruthenus, Linnaeus 1758) caused by different levels of fasting. Before testing, the four groups of sturgeon (body length: 12.1-15.4 cm, body mass: 10.0-20.2 g) fasted for 6 h, 2 days, 1 and 2 weeks, respectively. Swimming tests were then performed to measure critical swimming speed and oxygen consumption at 20 ± 0.5 °C. Results show: (1) Fasting times shorter than 2 days has little effect on swimming capability, but it decreases significantly when the fasting time is longer than a week. (2) After 2 weeks of fasting, swimming efficiency is significantly reduced. (3) Anaerobic capacity increases when digestion nears completion.

  17. Anaerobic Co-Digestion of Canola Straw and Buffalo Dung: Optimization of Methane Production in Batch Experiments

    Directory of Open Access Journals (Sweden)

    Abdul Razaque Sahito

    2014-01-01

    Full Text Available In several regions of the Pakistan, crop cultivation is leading to the production crop residues and its disposal problems. It has been suggested that the co-digestion of the crop residues with the buffalo dung might be a disposal way for the wasted portion of the crops' residue. The objective of present study was to optimize the anaerobic co-digestion of canola straw and the buffalo dung through batch experiments in order to obtain maximum methane production. The optimization was carried out in three stages. In first stage, the best canola straw to buffalo dung ratio was evaluated. In second stage, the best concentration of sodium hydrogen carbonate was assessedas the alkaline pretreatment chemical, whereas in the third stage most suitable particle size of the canola strawwas evaluated. The assessment criteria for the optimization of a co-digestion were cumulative methane production and ABD (Anaerobic Biodegradability. The results yield that anaerobic co-digestibility of the canola straw and the buffalo dung is obviously influenced by all the three factors of optimization. The maximum methane production was obtained as 911 NmL from the canola straw to buffalo dung ratio of 40:60, the alkaline doze of 0.6 gNaHCO3 / gVS and canola straw particle size of 2mm. However, because of the higher shredding cost to produce 2mm sized canola straw, particle size 4mm could be the best canola straw particle size.

  18. Intraspecific variation in aerobic and anaerobic locomotion

    DEFF Research Database (Denmark)

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

    2015-01-01

    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady...... to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3...

  19. Energy from anaerobic methane production. [Sweden

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Anaerobic degradation and toxicity of commercial cationic surfactants in anaerobic screening tests.

    Science.gov (United States)

    García, M T; Campos, E; Sánchez-Leal, J; Ribosa, I

    2000-09-01

    Anaerobic biodegradability and toxicity on anaerobic bacteria of di(hydrogenated tallow) dimethyl ammonium chloride (DHTDMAC) and two esterquats have been investigated. A batch test system containing municipal digester solids as a source of anaerobic bacteria, based on the method proposed by the ECETOC, has been applied. To evaluate the potential toxicity of such surfactants on anaerobic sludge, a co-substrate, an easily biodegradable compound in anaerobic conditions, has been added to the samples to test and the effects on biogas production have been determined. For the esterquats studied high biodegradation levels were obtained and no toxic effects on anaerobic bacteria were observed even at the highest concentrations tested, 100 and 200 mg C/l, respectively. On the contrary, DHTDMAC was not degradated at the same test conditions. However, no inhibitory effects on the biogas production were detected for this surfactant at concentrations <100 mg C/l.

  1. Thoracic and respirable particle definitions for human health risk assessment

    Science.gov (United States)

    Provides estimates of the thoracic and respirable fractions, for adults and children during typical activities during both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of evidence of health effects.

  2. Temperature response of soil respiration largely unaltered with experimental warming

    DEFF Research Database (Denmark)

    Carey, Joanna C; Tang, Jianwu; Templer, Pamela H

    2016-01-01

    considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic......The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific...... attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies...

  3. The Effect of Alkaline Material Particle Size on Adjustment Ability of Buffer Capacity

    Directory of Open Access Journals (Sweden)

    Girts Bumanis

    2015-09-01

    Full Text Available The pH control in biotechnological processes like anaerobic digestion is one of the key factors to ensure high efficiency in the biogas production process. The decrease of pH level in the digestion process occurs due to the rapid acid formation during metabolic processes of bacteria which leads to the inhibition of the methane producing bacteria; therefore further digestion process is limited. The efficiency of anaerobic digestion reactor decreases dramatically if the pH level falls under pH 6.6. This problem is common for single-stage continuous digesters with a high organic solid content; therefore the active pH controlling method is commonly used. By creating inorganic alkaline material, the passive pH controlling system could be created. Soluble alkalis are enclosed in the matrix of material during the activation process thus providing slow leaching of free alkalis from the material structure in water medium and ensuring pH increase. In this research a porous alkaline composite material was developed as a pH controlling agent for the biogas production. Two mixture compositions with a different Si/Al and Si/Na ratio were created. The effect of particle size of the material was investigated in order to provide different leaching rates for the described material. Granular material with particle fractions 1/2 mm, 2/4 mm and 4/8 mm and a cubical specimen with dimensions 20×20×20 mm were tested. The pH level of water medium increased up to pH 11.6 during the first day and final pH value decreased to 7.8 after 20-day leaching. Alkali leaching can be increased by 19-32% changing the mixture composition by adding glass powder to the alkaline material. The particle size factor was negligible for leaching rate of alkaline material due to the high porosity of material. Research results show that this composite material has a potential to be applied in pH control for biotechnological purposes.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7325

  4. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    Directory of Open Access Journals (Sweden)

    C. L. Phillips

    2012-02-01

    Full Text Available Distinct aggregations of fungal hyphae and rhizomorphs, or "mats" formed by some genera of ectomycorrhizal (EcM fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in Western Oregon to investigate whether there was an incremental increase in respiration from mat soils, and to estimate mat contributions to total soil respiration. We found that areas where Piloderma mats colonized the organic horizon often had higher soil surface flux than non-mats, with the incremental increase in respiration averaging 16 % across two growing seasons. Both soil physical factors and biochemistry were related to the higher surface flux of mat soils. When air-filled pore space was low (high soil moisture, soil CO2 production was concentrated into near-surface soil horizons where mats tend to colonize, resulting in greater apparent differences in respiration between mat and non-mat soils. Respiration rates were also correlated with the activity of chitin-degrading soil enzymes. This suggests that the elevated activity of fungal mats may be related to consumption or turnover of chitinous fungal cell-wall materials. We found Piloderma mats present across 57 % of the soil surface in the study area, and use this value to estimate a respiratory contribution from mats at the stand-scale of about 9 % of total soil respiration. The activity of EcM mats, which includes both EcM fungi and microbial associates, was estimated to constitute a substantial portion of total soil respiration in this old-growth Douglas-fir forest.

  5. Small ecosystem engineers as important regulators of lake's sediment respiration.

    Science.gov (United States)

    Baranov, Victor; Lewandowski, Joerg; Krause, Stefan; Romeijn, Paul

    2016-04-01

    Although shallow lakes are covering only about 1.5% of the land surface of the Earth, they are responsible for sequestration of carbon amounts similar or even larger than those sequestered in all marine sediments. One of the most important drivers of the carbon sequestration in lakes is sediment respiration. Especially in shallow lakes, bioturbation, i.e. the biogenic reworking of the sediment matrix and the transport of fluids within the sediment, severely impacts on sediment respiration. Widespread freshwater bioturbators such as chironomid larvae (Diptera, Chironomidae) are building tubes in the sediment and actively pump water through their burrows (ventilation). In the present work we study how different organism densities and temperatures (5-30°C) impact on respiration rates. In a microcosm experiment the bioreactive resazurin/resorufin smart tracer system was applied for quantifying the impacts of different densities of Chironomidae (Diptera) larvae (0, 1000, 2000 larvae/m2) on sediment respiration. Tracer transformation rates (and sediment respiration) were correlated with larval densities with highest transformation rates occurring in microcosms with highest larval densities. Respiration differences between defaunated sediment and sediment with 1000 and 2000 larvae per m2 was insignificant at 5 °C, and was progressively increasing with rising temperatures. At 30 °C respiration rates of sediment with 2000 larvae per m2 was 4.8 times higher than those of defaunated sediment. We interpret this as an effect of temperature on larval metabolic and locomotory activity. Furthermore, bacterial communities are benefiting from the combination of the high water temperatures and bioirrigation as bacterial community are able to maintain high metabolic rates due to oxygen supplied by bioirrigation. In the context of global climate change that means that chironomid ecosystem engineering activity will have a profound and increasing impact on lake sediment respiration

  6. Tai Chi training reduced coupling between respiration and postural control.

    Science.gov (United States)

    Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

    2016-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (ppostural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part from optimization of this multi-system interaction.

  7. The alkaline diet: is there evidence that an alkaline pH diet benefits health?

    Science.gov (United States)

    Schwalfenberg, Gerry K

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

  8. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    Directory of Open Access Journals (Sweden)

    Gerry K. Schwalfenberg

    2012-01-01

    Full Text Available This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

  9. Functional roles of arcA, etrA, cyclic AMP (cAMP)-cAMP receptor protein, and cya in the arsenate respiration pathway in Shewanella sp. strain ANA-3.

    Science.gov (United States)

    Murphy, Julie N; Durbin, K James; Saltikov, Chad W

    2009-02-01

    Microbial arsenate respiration can enhance arsenic release from arsenic-bearing minerals--a process that can cause arsenic contamination of water. In Shewanella sp. strain ANA-3, the arsenate respiration genes (arrAB) are induced under anaerobic conditions with arsenate and arsenite. Here we report how genes that encode anaerobic regulator (arcA and etrA [fnr homolog]) and carbon catabolite repression (crp and cya) proteins affect arsenate respiration in ANA-3. Transcription of arcA, etrA, and crp in ANA-3 was similar in cells grown on arsenate and cells grown under aerobic conditions. ANA-3 strains lacking arcA and etrA showed minor to moderate growth defects, respectively, with arsenate. However, crp was essential for growth on arsenate. In contrast to the wild-type strain, arrA was not induced in the crp mutant in cultures shifted from aerobic to anaerobic conditions containing arsenate. This indicated that cyclic AMP (cAMP)-cyclic AMP receptor (CRP) activates arr operon transcription. Computation analysis for genome-wide CRP binding motifs identified a putative binding motif within the arr promoter region. This was verified by electrophoretic mobility shift assays with cAMP-CRP and several DNA probes. Lastly, four putative adenylate cyclase (cya) genes were identified in the genome. One particular cya-like gene was differentially expressed under aerobic versus arsenate respiration conditions. Moreover, a double mutant lacking two of the cya-like genes could not grow with arsenate as a terminal electron acceptor; exogenous cAMP could complement growth of the double cya mutant. It is concluded that the components of the carbon catabolite repression system are essential to regulating arsenate respiratory reduction in Shewanella sp. strain ANA-3.

  10. Effects of lipid concentration on anaerobic co-digestion of municipal biomass wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yifei, E-mail: sunif@buaa.edu.cn [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Wang, Dian; Yan, Jiao [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Qiao, Wei [College of Chemical Science and Engineering, China University of Petroleum, Beijing 102249 (China); Wang, Wei [School of Environment, Tsinghua University, Beijing 100084 (China); Zhu, Tianle [School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2014-06-01

    Highlights: • Lipid in municipal biomass would not inhibited the anaerobic digestion process. • A lipid concentration of 65% of total VS was the inhibition concentration. • The amount of Brevibacterium decreased with the increasing of the lipid contents. • Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process. - Abstract: The influence of the lipid concentration on the anaerobic co-digestion of municipal biomass waste and waste-activated sludge was assessed by biochemical methane potential (BMP) tests and by bench-scale tests in a mesophilic semi-continuous stirred tank reactor. The effect of increasing the volatile solid (VS) concentration of lipid from 0% to 75% was investigated. BMP tests showed that lipids in municipal biomass waste could enhance the methane production. The results of bench-scale tests showed that a lipids concentration of 65% of total VS was the inhibition concentration. Methane yields increased with increasing lipid concentration when lipid concentrations were below 60%, but when lipid concentration was set as 65% or higher, methane yields decreased sharply. When lipid concentrations were below 60%, the pH values were in the optimum range for the growth of methanogenic bacteria and the ratios of volatile fatty acid (VFA)/alkalinity were in the range of 0.2–0.6. When lipid concentrations exceeded 65%, the pH values were below 5.2, the reactor was acidized and the values of VFA/alkalinity rose to 2.0. The amount of Brevibacterium decreased with increasing lipid content. Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process, thereby inhibiting anaerobic digestion.

  11. Anaerobic filter reactor performance for the treatment of complex dairy wastewater at industrial scale.

    Science.gov (United States)

    Omil, Francisco; Garrido, Juan M; Arrojo, Belén; Méndez, Ramón

    2003-10-01

    The wastewaters discharged by raw milk quality control laboratories are more complex than the ones commonly generated by dairy factories because of the presence of certain chemicals such as sodium azide or chloramphenicol, which are used for preserving milk before analysis. The treatment of these effluents has been carried out in a full-scale plant comprising a 12 m(3) anaerobic filter (AF) reactor and a 28 m(3) sequential batch reactor (SBR). After more than 2 years of operation, a successful anaerobic treatment of these effluents was achieved, without fat removal prior to the anaerobic reactor. The organic loading rates maintained in the AF reactor were 5-6 kg COD/m(3) d, with COD removal being higher than 90%. No biomass washout was observed, and most of the fat contained in the wastewaters was successfully degraded. The addition of alkalinity is crucial for the maintenance of a proper buffer medium to ensure pH stability. The effluent of the AF reactor was successfully treated in the SBR reactor, and a final effluent with a COD content below 200 mg/l and total nitrogen below 10mg N/l was obtained.

  12. Anaerobic co-digestion of the marine microalga Nannochloropsis salina with energy crops.

    Science.gov (United States)

    Schwede, Sebastian; Kowalczyk, Alexandra; Gerber, Mandy; Span, Roland

    2013-11-01

    Anaerobic co-digestion of corn silage with the marine microalga Nannochloropsis salina was investigated under batch and semi-continuous conditions. Under batch conditions process stability and biogas yields significantly increased by microalgae addition. During semi-continuous long-term experiments anaerobic digestion was stable in corn silage mono- and co-digestion with the algal biomass for more than 200 days. At higher organic loading rates (4.7 kg volatile solids m(-3)d(-1)) inhibition and finally process failure occurred in corn silage mono-digestion, whereas acid and methane formation remained balanced in co-digestion. The positive influences in co-digestion can be attributed to an adjusted carbon to nitrogen ratio, enhanced alkalinity, essential trace elements and a balanced nutrient composition. The results suggest that N. salina biomass is a suitable feedstock for anaerobic co-digestion of energy crops, especially for regions with manure scarcity. Enhanced process stability may result in higher organic loading rates or lower digester volumes.

  13. Antimicrobial resistance and susceptibility testing of anaerobic bacteria.

    Science.gov (United States)

    Schuetz, Audrey N

    2014-09-01

    Infections due to anaerobic bacteria can be severe and life-threatening. Susceptibility testing of anaerobes is not frequently performed in laboratories, but such testing is important to direct appropriate therapy. Anaerobic resistance is increasing globally, and resistance trends vary by geographic region. An overview of a variety of susceptibility testing methods for anaerobes is provided, and the advantages and disadvantages of each method are reviewed. Specific clinical situations warranting anaerobic susceptibility testing are discussed.

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

    Directory of Open Access Journals (Sweden)

    M.T. Kato

    1997-12-01

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

  15. Two Proximal Skin Electrodes — A Respiration Rate Body Sensor

    Directory of Open Access Journals (Sweden)

    Viktor Avbelj

    2012-10-01

    Full Text Available We propose a new body sensor for extracting the respiration rate based on the amplitude changes in the body surface potential differences between two proximal body electrodes. The sensor could be designed as a plaster-like reusable unit that can be easily fixed onto the surface of the body. It could be equipped either with a sufficiently large memory for storing the measured data or with a low-power radio system that can transmit the measured data to a gateway for further processing. We explore the influence of the sensor’s position on the quality of the extracted results using multi-channel ECG measurements and considering all the pairs of two neighboring electrodes as potential respiration-rate sensors. The analysis of the clinical measurements, which also include reference thermistor-based respiration signals, shows that the proposed approach is a viable option for monitoring the respiration frequency and for a rough classification of breathing types. The obtained results were evaluated on a wireless prototype of a respiration body sensor. We indicate the best positions for the respiration body sensor and prove that a single sensor for body surface potential difference on proximal skin electrodes can be used for combined measurements of respiratory and cardiac activities.

  16. Respiration during Postharvest Development of Soursop Fruit, Annona muricata L.

    Science.gov (United States)

    Bruinsma, J; Paull, R E

    1984-09-01

    Fruit of soursop, Annona muricata L., showed increased CO(2) production 2 days after harvest, preceding the respiratory increase that coincided with autocatalytic ethylene evolution and other ripening phenomena. Experiments to alter gas exchange patterns of postharvest fruit parts and tissue cylinders had little success.The respiratory quotient of tissue discs was near unity throughout development. 2,4-Dinitrophenol uncoupled respiration more effectively than carbonylcyanide m-chlorophenylhydrazone; 0.4 millimolar KCN stimulated, 4 millimolar salicylhydroxamic acid slightly inhibited, and their combination strongly inhibited respiration, as did 10 millimolar NaN(3). Tricarboxylic acid cycle members and ascorbate were more effective substrates than sugars, but acetate and glutarate strongly inhibited.Disc respiration showed the same early peak as whole fruit respiration; this peak is thus an inherent characteristic of postharvest development and cannot be ascribed to differences between ovaries of the aggregatetype fruit. The capacity of the respiratory apparatus did not change during this preclimacteric peak, but the contents of rate-limiting malate and citrate increased after harvest.It is concluded that the preclimacteric rise in CO(2) evolution reflects increased mitochondrial respiration because of enhanced supply of carboxylates as a substrate, probably induced by detachment from the tree. The second rise corresponds with the respiration during ripening of other climacteric fruits.

  17. Surfactants and the Mechanics of Respiration

    Science.gov (United States)

    Jbaily, Abdulrahman; Szeri, Andrew J.

    2016-11-01

    Alveoli are small sacs found at the end of terminal bronchioles in human lungs with a mean diameter of 200 μm. A thin layer of fluid (hypophase) coats the inner face of an alveolus and is in contact with the air in the lungs. The thickness of this layer varies among alveoli, but is in the range of 0.1 to 0.5 μm for many portions of the alveolar network. The interfacial tension σ at the air-hypophase interface tends to favor collapse of the alveolus, and resists its expansion during inhalation. Type II alveolar cells synthesize and secrete a mixture of phospholipids and proteins called pulmonary surfactant. These surfactant molecules adsorb to the interface causing σ of water at body temperature is 70 mN/m and falls to an equilibrium value of 25 mN/m when surfactants are present. Also, in a dynamic sense, it is known that σ is reduced to near 0 during exhalation when the surfactant film compresses. In this work, the authors develop a mechanical and transport model of the alveolus to study the effect of surfactants on various aspects of respiration. The model is composed of three principal parts: (i) air movement into and out of the alveolus; (ii) a balance of linear momentum across the two-layered membrane of the alveolus (hypophase and elastic wall); and (iii) a pulmonary surfactant transport problem in the hypophase. The goal is to evaluate the influence of pulmonary surfactant on respiratory mechanics.

  18. A global database of soil respiration data

    Science.gov (United States)

    Bond-Lamberty, B.; Thomson, A.

    2010-06-01

    Soil respiration - RS, the flux of CO2 from the soil to the atmosphere - is probably the least well constrained component of the terrestrial carbon cycle. Here we introduce the SRDB database, a near-universal compendium of published RS data, and make it available to the scientific community both as a traditional static archive and as a dynamic community database that may be updated over time by interested users. The database encompasses all published studies that report one of the following data measured in the field (not laboratory): annual RS, mean seasonal RS, a seasonal or annual partitioning of RS into its sources fluxes, RS temperature response (Q10), or RS at 10 °C. Its orientation is thus to seasonal and annual fluxes, not shorter-term or chamber-specific measurements. To date, data from 818 studies have been entered into the database, constituting 3379 records. The data span the measurement years 1961-2007 and are dominated by temperate, well-drained forests. We briefly examine some aspects of the SRDB data - its climate space coverage, mean annual RS fluxes and their correlation with other carbon fluxes, RS variability, temperature sensitivities, and the partitioning of RS source flux - and suggest some potential lines of research that could be explored using these data. The SRDB database is available online in a permanent archive as well as via a project-hosting repository; the latter source leverages open-source software technologies to encourage wider participation in the database's future development. Ultimately, we hope that the updating of, and corrections to, the SRDB will become a shared project, managed by the users of these data in the scientific community.

  19. Biomass production on saline-alkaline soils

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, A.N.

    1985-01-01

    In a trial of twelve tree species (both nitrogen fixing and non-fixing) for fuel plantations on saline-alkaline soil derived from Gangetic alluvium silty clay, Leucaena leucocephala failed completely after showing rapid growth for six months. Results for other species at age two showed that Prosopis juliflora had the best productivity.

  20. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    Science.gov (United States)

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management.

  1. Alkaline electrochemical cells and method of making

    Science.gov (United States)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  2. 42 CFR 84.254 - Powered air-purifying respirators; requirements and tests.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Powered air-purifying respirators; requirements and... DEVICES Special Use Respirators § 84.254 Powered air-purifying respirators; requirements and tests. (a... air-purifying respirators prescribed in subpart L of this part are applicable to vinyl...

  3. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... respirators; minimum requirements. 84.1147 Section 84.1147 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1147 Silica mist test for dust, fume, and mist respirators; minimum requirements. (a) Three non-powered respirators will be tested for a period of...

  4. 42 CFR 84.50 - Types of respirators to be approved; scope of approval.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Types of respirators to be approved; scope of... Classification of Approved Respirators; Scope of Approval; Atmospheric Hazards; Service Time § 84.50 Types of respirators to be approved; scope of approval. Approvals shall be issued for the types of respirators...

  5. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Lead fume test for dust, fume, and mist respirators... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators; minimum requirements. (a) Three non-powered respirators will be tested for a period of...

  6. 42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.170 Non-powered air-purifying particulate respirators; description. (a) Non-powered air-purifying particulate respirators utilize the wearer's...

  7. 42 CFR 84.131 - Supplied-air respirators; required components.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Supplied-air respirators; required components. 84... Supplied-Air Respirators § 84.131 Supplied-air respirators; required components. (a) Each supplied-air respirator described in § 84.130 shall, where its design requires, contain the following component parts:...

  8. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist respirators; performance... Respirators and Combination Gas Masks § 84.1140 Dust, fume, and mist respirators; performance requirements; general. Dust, fume, and mist respirators and the individual components of each such device shall,...

  9. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... RESPIRATORY PROTECTIVE DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.179 Non-powered air-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of...

  10. 42 CFR 84.147 - Type B supplied-air respirator; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Type B supplied-air respirator; minimum... DEVICES Supplied-Air Respirators § 84.147 Type B supplied-air respirator; minimum requirements. No Type B supplied-air respirator shall be approved for use with a blower or with connection to an air supply...

  11. 42 CFR 84.253 - Chemical-cartridge respirators; requirements and tests.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical-cartridge respirators; requirements and... DEVICES Special Use Respirators § 84.253 Chemical-cartridge respirators; requirements and tests. (a... for chemical-cartridge respirators prescribed in Subpart L of this part are applicable to...

  12. 42 CFR 84.206 - Particulate tests; respirators with filters; minimum requirements; general.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Particulate tests; respirators with filters... RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.206 Particulate tests; respirators with filters; minimum requirements; general. (a) Three respirators with cartridges containing, or...

  13. 42 CFR 84.139 - Head and neck protection; supplied-air respirators; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head and neck protection; supplied-air respirators... PROTECTIVE DEVICES Supplied-Air Respirators § 84.139 Head and neck protection; supplied-air respirators; minimum requirements. Type AE, BE, and CE supplied-air respirators shall be designed and constructed...

  14. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist tests; respirators with...-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1158 Dust, fume, and mist tests; respirators with filters; minimum requirements; general. (a) Three respirators with cartridges containing,...

  15. 42 CFR 84.148 - Type C supplied-air respirator, continuous flow class; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Type C supplied-air respirator, continuous flow... RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.148 Type C supplied-air respirator, continuous flow class; minimum requirements. (a) Respirators tested under this section shall be approved only...

  16. Exocellular electron transfer in anaerobic microbial communities

    NARCIS (Netherlands)

    Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

    2006-01-01

    Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

  17. An anaerobic mitochondrion that produces hydrogen

    NARCIS (Netherlands)

    Boxma, Brigitte; Graaf, Rob M. de; Staay, Georg W.M. van der; Alen, Theo A. van; Ricard, Guenola; Gabaldón, Toni; Hoek, Angela H.A.M. van; Moon-van der Staay, Seung Yeo; Koopman, Werner J.H.; Hellemond, Jaap J. van; Tielens, Aloysius G.M.; Friedrich, Thorsten; Veenhuis, Marten; Huynen, Martijn A.; Hackstein, Johannes H.P.

    2005-01-01

    Hydrogenosomes are organelles that produce ATP and hydrogen, and are found in various unrelated eukaryotes, such as anaerobic flagellates, chytridiomycete fungi and ciliates. Although all of these organelles generate hydrogen, the hydrogenosomes from these organisms are structurally and metabolicall

  18. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Toxicity data for the impact of nano-silver on anaerobic degradation. This dataset is associated with the following publication: Gitipour, A., S. Thiel, K. Scheckel,...

  19. Anaerobic membrane bioreactor under extreme conditions (poster)

    NARCIS (Netherlands)

    Munoz Sierra, J.D.; De Kreuk, M.K.; Spanjers, H.; Van Lier, J.B.

    2013-01-01

    Membrane bioreactors ensure biomass retention by the application of micro or ultrafiltration processes. This allows operation at high sludge concentrations. Previous studies have shown that anaerobic membrane bioreactors is an efficient way to retain specialist microorganisms for treating wastewater

  20. Influences of Quinclorac on Culturable Microorganisms and Soil Respiration in Flooded Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    ZHEN-MEI LU; HANG MIN; YANG-FANG YE

    2003-01-01

    Objective To investigate the potential effects of herbicide quinclorac (3,7-dichloro-8-quinoline-carboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes and fungi were counted by a 10-fold serial dilution plate technique. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN)methods with anaerobic liquid enrichment media. The number of methanogenic bacteria (MB) and nitrogen-fixing bacteria (NFB) was determined by the rolling tube method in triplicate. Soil respiration was monitored by a 102G-type gas chromatography with a stainless steel column filled with GDX-104 and a thermal conductivity detector. Results Quinclorac concentration was an important factor affecting the populations of various culturable microorganisms. There were some significant differences in the aerobic heterotrophic bacteria. AFB and DNB between soils were supplemented with quinclorac and non-quinclorac at the early stage of incubation, but none of them was persistent. The number of fungi and DNB was increased in soil samples treated by lower than1.33 μg·g-1 dried soil, while the CFU of fungi and HPAB was inhibited in soil samples treated by higher than 1.33 μg·g-1 dried soil. The population of actinomycete declined in negative proportion to the concentrations of quinclorac applied after 4 days. However, application of quinclorac greatly stimulated the growth of AFB and NFB. MB was more sensitive to quinclorac than the others, and the three soil samples with concentrations higher than 1 μg·g-1 dried soil declined significantly to less than 40% of that in the control, but the number of samples with lower concentrations of quinclorac was nearly equal to that in the control at the end of experiments. Conclusion Quinclorac is safe to the soil microorganisms when applied at normal

  1. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    OpenAIRE

    Atan, T.

    2013-01-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-...

  2. Anaerobic digester for treatment of organic waste

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V. K. [Indian Insitute of Technology, Delhi (India)]|[ENEA, Centro Ricerche Trisaia, Matera (Italy); Fortuna, F.; Canditelli, M.; Cornacchia, G. [ENEA, Centro Ricerche Trisaia, Matera (Italy). Dipt. Ambiente; Farina, R. [ENEA, centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Ambiente

    1997-09-01

    The essential features of both new and more efficient reactor systems and their appropriate applications for various organic waste management situations, description of several working plants are discussed in the present communication. It is hoped that significant development reported here would be useful in opening a new vista to the application of anaerobic biotechnology for the waste treatment of both low/high organic strength and specialized treatment for toxic substances, using appropriate anaerobic methods.

  3. Anaerobic digestion foaming causes – A review

    OpenAIRE

    Ganidi, Nafsika; Tyrrel, Sean F.; Cartmell, Elise

    2009-01-01

    Anaerobic digestion foaming has been encountered in several sewage treatment plants in the UK. Foaming has raised major concerns for the water companies due to significant impacts on process efficiency and operational costs. Several foaming causes have been identified over the past few years by researchers. However, the supporting experimental information is limited and in some cases absent. The present report aims to provide a detailed review of the current anaerobic digestion foaming proble...

  4. Titanium corrosion in alkaline hydrogen peroxide environments

    Science.gov (United States)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  5. [Factors influencing the spatial variability in soil respiration under different land use regimes].

    Science.gov (United States)

    Chen, Shu-Tao; Liu, Qiao-Hui; Hu, Zheng-Hua; Liu, Yan; Ren, Jing-Quan; Xie, Wei

    2013-03-01

    In order to investigate the factors influencing the spatial variability in soil respiration under different land use regimes, field experiments were performed. Soil respiration and relevant environment, vegetation and soil factors were measured. The spatial variability in soil respiration and the relationship between soil respiration and these measured factors were investigated. Results indicated that land use regimes had significant effects on soil respiration. Soil respiration varied significantly (P DBH) of trees can be explained by a natural logarithmic function. A model composed of soil organic carbon (C, %), available phosphorous (AP, g x kg(-1)) and diameter at breast height (DBH, cm) explained 92.8% spatial variability in soil respiration for forest ecosystems.

  6. Effect of vegetation of transgenic Bt rice lines and their straw amendment on soil enzymes, respiration, functional diversity and community structure of soil microorganisms under field conditions.

    Science.gov (United States)

    Fang, Hua; Dong, Bin; Yan, Hu; Tang, Feifan; Wang, Baichuan; Yu, Yunlong

    2012-01-01

    With the development of transgenic crops, there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality. This study was carried out to evaluate the possible effects of the vegetation of transgenic Bt rice lines Huachi B6 (HC) and TT51 (TT) followed by the return of their straw to the soil on soil enzymes (catalase, urease, neutral phosphatase and invertase), anaerobic respiration activity, microbial utilization of carbon substrates and community structure, under field conditions. The results indicated that the vegetation of the two transgenic rice lines (HC and TT) and return of their straw had few adverse effects on soil enzymes and anaerobic respiration activity compared to their parent and distant parent, although some transient differences were observed. The vegetation and subsequent straw amendment of Bt rice HC and TT did not appear to have a harmful effect on the richness, evenness and community structure of soil microorganisms. No different pattern of impact due to plant species was found between HC and TT. It could be concluded that the vegetation of transgenic Bt rice lines and the return of their straw as organic fertilizer may not alter soil microbe-mediated functions.

  7. Effect of vegetation of transgenic Bt rice lines and their straw amendment on soil enzymes, respiration, functional diversity and community structure of soil microorganisms under field conditions

    Institute of Scientific and Technical Information of China (English)

    Hua Fang; Bin Dong; Hu Yan; Feifan Tang; Baichuan Wang; Yunlong Yu

    2012-01-01

    With the development of transgenic crops,there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality.This study was carried out to evaluate the possible effects of the vegetation of transgenic Bt rice lines Huachi B6 (HC) and TT51 (TT) followed by the return of their straw to the soil on soil enzymes (catalase,arease,neutral phosphatase and invertase),anaerobic respiration activity,microbial utilization of carbon substrates and community structure,under field conditions.The results indicated that the vegetation of the two transgenic rice lines (HC and TT) and return of their straw had few adverse effects on soil enzymes and anaerobic respiration activity compared to their parent and distant parent,although some transient differences were observed.The vegetation and subsequent straw amendment of Bt rice HC and TT did not appear to have a harmful effect on the richness,evenness and community structure of soil microorganisms.No different pattern of impact due to plant species was found between HC and TT.It could be concluded that the vegetation of transgenic Bt rice lines and the return of their straw as organic fertilizer may not alter soil microbe-mediated functions.

  8. SLEEP DEPRIVATION INDUCED ANXIETY AND ANAEROBIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Selma Arzu Vardar

    2007-12-01

    Full Text Available The aim of this study was to investigate the effects of sleep deprivation induced anxiety on anaerobic performance. Thirteen volunteer male physical education students completed the Turkish version of State Anxiety Inventory and performed Wingate anaerobic test for three times: (1 following a full-night of habitual sleep (baseline measurements, (2 following 30 hours of sleep deprivation, and (3 following partial-night sleep deprivation. Baseline measurements were performed the day before total sleep deprivation. Measurements following partial sleep deprivation were made 2 weeks later than total sleep deprivation measurements. State anxiety was measured prior to each Wingate test. The mean state anxiety following total sleep deprivation was higher than the baseline measurement (44.9 ± 12.9 vs. 27.6 ± 4.2, respectively, p = 0.02 whereas anaerobic performance parameters remained unchanged. Neither anaerobic parameters nor state anxiety levels were affected by one night partial sleep deprivation. Our results suggest that 30 hours continuous wakefulness may increase anxiety level without impairing anaerobic performance, whereas one night of partial sleep deprivation was ineffective on both state anxiety and anaerobic performance

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

    Science.gov (United States)

    Koupaie, E Hosseini; Moghaddam, M R Alavi; Hashemi, S H

    2011-11-15

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

  10. Improved electrodes and gas impurity investigations on alkaline electrolysers

    DEFF Research Database (Denmark)

    Reissner, R.; Schiller, G.; Knoeri, T.;

    Alkaline water electrolysis for hydrogenproduction is a well-established techniquebut some technological issues regarding thecoupling of alkaline water electrolysis andRenewable Energy Sources (RES) remain tobe improved....

  11. Respirator studies for the ERDA Division of Safety, Standards, and Compliance, July 1, 1975--June 30, 1976. [Physiological effects of wearing respirators

    Energy Technology Data Exchange (ETDEWEB)

    Davis, T.O.; Raven, P.B.; Shafer, C.L.; Linnebur, A.C.; Bustos, J.M.; Wheat, L.D.; Douglas, D.D.

    1977-03-01

    Results of a study to determine what effect wearing a respirator has on worker performance, and which physiological parameters an industrial physician should consider when examining an employee who will be wearing a respirator while working are presented. (TFD)

  12. Ammonium nitrogen removal from the permeates of anaerobic membrane bioreactors: economic regeneration of exhausted zeolite.

    Science.gov (United States)

    Deng, Qiaosi; Dhar, Bipro Ranjan; Elbeshbishy, Elsayed; Lee, Hyung-Sool

    2014-08-01

    This study revealed that ammonium exchange of natural zeolite could be an economical method of nitrogen removal from the permeates of anaerobic membrane bioreactors (AnMBRs). It was found that the mass ratio of Na+ to Zeolite - NH4+ - N significantly affected regeneration efficiency (RE), not simply NaCI concentration. Batch experiments showed that the mass ratio of 750g Na+/g Zeolite - NH4+ - N was required to achieve RE over 90% in 2h at pH 9. However, the alkaline regeneration at pH 12 significantly decreased the mass ratio down to 4.2 in batch tests. It was confirmed that the alkaline regeneration only needed NaCl 10 g/L (the mass of Na+ to Zeolite - NH4+ - N of 4.2) for RE of 85% in 2 h of reaction time in continuous column tests. Economic analysis showed that this alkaline regeneration decreased chemical costs over 10 times as compared with a conventional regeneration method. A significant bottleneck of zeolite processes would be the requirement of substituting exhausted zeolite with virgin one, due to the reductions of ammonium exchange capacity and RE.

  13. Tillage-induced short-term soil organic matter turnover and respiration

    Science.gov (United States)

    Fiedler, Sebastian Rainer; Leinweber, Peter; Jurasinski, Gerald; Eckhardt, Kai-Uwe; Glatzel, Stephan

    2016-09-01

    Tillage induces decomposition and mineralisation of soil organic matter (SOM) by the disruption of macroaggregates and may increase soil CO2 efflux by respiration, but these processes are not well understood at the molecular level. We sampled three treatments (mineral fertiliser: MF; biogas digestate: BD; unfertilised control: CL) of a Stagnic Luvisol a few hours before and directly after tillage as well as 4 days later from a harvested maize field in northern Germany and investigated these samples by means of pyrolysis-field ionisation mass spectrometry (Py-FIMS) and hot-water extraction. Before tillage, the Py-FIMS mass spectra revealed differences in relative ion intensities of MF and CL compared to BD most likely attributable to the cattle manure used for the biogas feedstock and to relative enrichments during anaerobic fermentation. After tillage, the CO2 effluxes were increased in all treatments, but this increase was less pronounced in BD. We explain this by restricted availability of readily biodegradable carbon compounds and possibly an inhibitory effect of sterols from digestates. Significant changes in SOM composition were observed following tillage. In particular, lignin decomposition and increased proportions of N-containing compounds were detected in BD. In MF, lipid proportions increased at the expense of ammonia, ammonium, carbohydrates and peptides, indicating enhanced microbial activity. SOM composition in CL was unaffected by tillage. Our analyses provide strong evidence for significant short-term SOM changes due to tillage in fertilised soils.

  14. Pyrogenic effect of respirable road dust particles

    Energy Technology Data Exchange (ETDEWEB)

    Jayawardena, Umesh; Tollemark, Linda; Tagesson, Christer; Leanderson, Per, E-mail: per.leanderson@lio.s [Occupational and Environmental Medicine, University Hospital, S-581 85 Linkoeping (Sweden)

    2009-02-01

    Because pyrogenic (fever-inducing) compounds on ambient particles may play an important role for particle toxicity, simple methods to measure pyrogens on particles are needed. Here we have used a modified in vitro pyrogen test (IPT) to study the release of interleukin 1beta (IL-1beta) in whole human blood exposed to respirable road-dust particles (RRDP). Road dusts were collected from the roadside at six different streets in three Swedish cities and particles with a diameter less than 10 mum (RRDP) were prepared by a water sedimentation procedure followed by lyophilisation. RRDP (200 mul of 1 - 10{sup 6} ng/ml) were mixed with 50 mul whole blood and incubated at 37 deg. C overnight before IL-1beta was analysed with chemiluminescence ELISA in 384-well plates. Endotoxin (lipopolysaccharide from Salmonella minnesota), zymosan B and Curdlan (P-1,3-glucan) were used as positive controls. All RRDP samples had a pyrogenic effect and the most active sample produced 1.6 times more IL-1beta than the least active. This formation was of the same magnitude as in samples with 10 ng LPS/ml and was larger than that evoked by zymosan B and Curdlan (by mass basis). The method was sensitive enough to determine formation of IL-1beta in mixtures with 10 ng RRDP/ml or 0.01 ng LPS/ml. The endotoxin inhibitor, polymyxin B (10 mug/ml), strongly reduced the RRDP-induced formation of IL-1beta at 1mug RRDP/ml (around 80 % inhibition), but had only marginal or no effects at higher RRDP-concentrations (10 and 100 mug /ml). In summary, all RRDP tested had a clear pyrogen effect in this in vitro model. Endotoxin on the particles but also other factors contributed to the pyrogenic effect. As opposed to the limulus amebocyte lysate (LAL) assay (which measures endotoxin alone), IPT measures a broad range of pyrogens that may be present on particulate matter. The IPT method thus affords a simple, sensitive and quantitative determination of the total pyrogenic potential of ambient particles.

  15. A global database of soil respiration data

    Directory of Open Access Journals (Sweden)

    B. Bond-Lamberty

    2010-06-01

    Full Text Available Soil respirationRS, the flux of CO2 from the soil to the atmosphere – is probably the least well constrained component of the terrestrial carbon cycle. Here we introduce the SRDB database, a near-universal compendium of published RS data, and make it available to the scientific community both as a traditional static archive and as a dynamic community database that may be updated over time by interested users. The database encompasses all published studies that report one of the following data measured in the field (not laboratory: annual RS, mean seasonal RS, a seasonal or annual partitioning of RS into its sources fluxes, RS temperature response (Q10, or RS at 10 °C. Its orientation is thus to seasonal and annual fluxes, not shorter-term or chamber-specific measurements. To date, data from 818 studies have been entered into the database, constituting 3379 records. The data span the measurement years 1961–2007 and are dominated by temperate, well-drained forests. We briefly examine some aspects of the SRDB data – its climate space coverage, mean annual RS fluxes and their correlation with other carbon fluxes, RS variability, temperature sensitivities, and the partitioning of RS source flux – and suggest some potential lines of research that could be explored using these data. The SRDB database is available online in a permanent archive as well as via a project-hosting repository; the latter source leverages open-source software technologies to encourage wider participation in the database's future development. Ultimately, we hope that the updating of, and corrections to, the SRDB will become a shared project, managed by the users of these data in the scientific community.

  16. A global database of soil respiration data

    Directory of Open Access Journals (Sweden)

    B. Bond-Lamberty

    2010-02-01

    Full Text Available Soil respirationRS, the flux of autotropically- and heterotrophically-generated CO2 from the soil to the atmosphere – remains the least well-constrained component of the terrestrial C cycle. Here we introduce the SRDB database, a near-universal compendium of published RS data, and make it available to the scientific community both as a traditional static archive and as a dynamic community database that will be updated over time by interested users. The database encompasses all published studies that report one of the following data measured in the field (not laboratory: annual RS, mean seasonal RS, a seasonal or annual partitioning of RS into its sources fluxes, RS temperature response (Q10, or RS at 10 °C. Its orientation is thus to seasonal and annual fluxes, not shorter-term or chamber-specific measurements. To date, data from 818 studies have been entered into the database, constituting 3379 records. The data span the measurement years 1961–2007 and are dominated by temperate, well-drained forests. We briefly examine some aspects of the SRDB data – mean annual RS fluxes and their correlation with other carbon fluxes, RS variability, temperature sensitivities, and the partitioning of RS source flux – and suggest some potential lines of research that could be explored using these data. The SRDB database described here is available online in a permanent archive as well as via a project-hosting repository; the latter source leverages open-source software technologies to encourage wider participation in the database's future development. Ultimately, we hope that the updating of, and corrections to, the SRDB will become a shared project, managed by the users of these data in the scientific community.

  17. Seasonality of temperate forest photosynthesis and daytime respiration

    Science.gov (United States)

    Wehr, R.; Munger, J. W.; McManus, J. B.; Nelson, D. D.; Zahniser, M. S.; Davidson, E. A.; Wofsy, S. C.; Saleska, S. R.

    2016-06-01

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem-atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night—the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest-atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems.

  18. Seasonality of temperate forest photosynthesis and daytime respiration.

    Science.gov (United States)

    Wehr, R; Munger, J W; McManus, J B; Nelson, D D; Zahniser, M S; Davidson, E A; Wofsy, S C; Saleska, S R

    2016-06-30

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem-atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night-the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest-atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems.

  19. Anaerobic Nitrogen Fixers on Mars

    Science.gov (United States)

    Lewis, B. G.

    2000-07-01

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

  20. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become m

  1. [Leucocyte alkaline phosphatase in normal and pathological pregnancy (author's transl)].

    Science.gov (United States)

    Stark, K H; Zaki, I; Sobolewski, K

    1981-01-01

    The activities of leucocyte alkaline phosphatase were determined in 511 patients with normal and pathological pregnancy. Mean values were compared and the enzyme followed up, and the conclusion was drawn that leucocyte alkaline phosphatase was no safe indicator of foetal condition. No direct relationship were found to exist between leucocyte alkaline phosphatase, total oestrogens, HSAP, HLAP, HPL, and oxytocinase.

  2. Respirable crystalline silica: Analysis methodologies; Silice cristalina respirable: Metodologias de analisis

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Tena, M. P.; Zumaquero, E.; Ibanez, M. J.; Machi, C.; Escric, A.

    2012-07-01

    This paper describes different analysis methodologies in occupational environments and raw materials. A review is presented of the existing methodologies, the approximations made, some of the constraints involved, as well as the best measurement options for the different raw materials. In addition, the different factors that might affect the precision and accuracy of the results are examined. With regard to the methodologies used for the quantitative analysis of any of the polymorph s, particularly of quartz, the study centres particularly on the analytical X-ray diffraction method. Simplified methods of calculation and experimental separation are evaluated for the estimation of this fraction in the raw materials, such as separation methods by centrifugation, sedimentation, and dust generation in controlled environments. In addition, a review is presented of the methodologies used for the collection of respirable crystalline silica in environmental dust. (Author)

  3. Automatic respiration tracking for radiotherapy using optical 3D camera

    Science.gov (United States)

    Li, Tuotuo; Geng, Jason; Li, Shidong

    2013-03-01

    Rapid optical three-dimensional (O3D) imaging systems provide accurate digitized 3D surface data in real-time, with no patient contact nor radiation. The accurate 3D surface images offer crucial information in image-guided radiation therapy (IGRT) treatments for accurate patient repositioning and respiration management. However, applications of O3D imaging techniques to image-guided radiotherapy have been clinically challenged by body deformation, pathological and anatomical variations among individual patients, extremely high dimensionality of the 3D surface data, and irregular respiration motion. In existing clinical radiation therapy (RT) procedures target displacements are caused by (1) inter-fractional anatomy changes due to weight, swell, food/water intake; (2) intra-fractional variations from anatomy changes within any treatment session due to voluntary/involuntary physiologic processes (e.g. respiration, muscle relaxation); (3) patient setup misalignment in daily reposition due to user errors; and (4) changes of marker or positioning device, etc. Presently, viable solution is lacking for in-vivo tracking of target motion and anatomy changes during the beam-on time without exposing patient with additional ionized radiation or high magnet field. Current O3D-guided radiotherapy systems relay on selected points or areas in the 3D surface to track surface motion. The configuration of the marks or areas may change with time that makes it inconsistent in quantifying and interpreting the respiration patterns. To meet the challenge of performing real-time respiration tracking using O3D imaging technology in IGRT, we propose a new approach to automatic respiration motion analysis based on linear dimensionality reduction technique based on PCA (principle component analysis). Optical 3D image sequence is decomposed with principle component analysis into a limited number of independent (orthogonal) motion patterns (a low dimension eigen-space span by eigen-vectors). New

  4. SELENIHALANAEROBACTER SHRIFTII GEN. NOV., SP. NOV., A HALOPHILIC ANAEROBE FROM DEAD SEA SEDIMENTS THAT RESPIRES SELENATE. (R826105)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. Distribution of microbial biomass and the potential for anaerobic respiration in Hanford Site 300 Area subsurface sediment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xueju; Kennedy, David W.; Peacock, Aaron D.; McKinley, James P.; Resch, Charles T.; Fredrickson, Jim K.; Konopka, Allan

    2012-02-01

    Subsurface sediments were recovered from a 52 m deep borehole cored in the 300 Area of the Hanford Site in southeastern Washington State to assess the potential for biogeochemical transformation of radionuclide contaminants. Microbial analyses were made on 17 sediment samples traversing multiple geological units: the oxic coarse-grained Hanford formation (9-17.4 m), the oxic fine-grained upper Ringold Formation (17.7-18.1 m), and the reduced Ringold Formation (18.3-52m). Microbial biomass (measured as phospholipid) ranged from 7-974 pmols per g in discrete samples, with the highest numbers found in the Hanford formation. On average, strata below 17.4 m had 13-fold less biomass than those from shallower strata. The nosZ gene encoding nitrous oxide reductase had an abundance of 5-17% relative to total 16S rRNA genes below 18.3 m and <5% above 18.1 m. Most nosZ sequences were affiliated with Ochrobactrum anthropi (97% sequence similarity) or had a nearest neighbor of Achromobacter xylosoxidans (90% similarity). Passive multilevel sampling of groundwater geochemistry demonstrated a redox gradient in the 1.5 m region between the Hanford-Ringold formation contact and the Ringold oxic-anoxic interface. Within this zone, copies of the dsrA gene and Geobacteraceae had the highest relative abundance. The majority of dsrA genes detected near the interface were related to Desulfotomaculum sp.. These analyses indicate that the region just below the contact between the Hanford and Ringold formations is a zone of active biogeochemical redox cycling.

  6. Cannabinoid-induced changes in respiration of brain mitochondria.

    Science.gov (United States)

    Fišar, Zdeněk; Singh, Namrata; Hroudová, Jana

    2014-11-18

    Cannabinoids exert various biological effects that are either receptor-mediated or independent of receptor signaling. Mitochondrial effects of cannabinoids were interpreted either as non-receptor-mediated alteration of mitochondrial membranes, or as indirect consequences of activation of plasma membrane type 1 cannabinoid receptors (CB1). Recently, CB1 receptors were confirmed to be localized to the membranes of neuronal mitochondria, where their activation directly regulates respiration and energy production. Here, we performed in-depth analysis of cannabinoid-induced changes of mitochondrial respiration using both an antagonist/inverse agonist of CB1 receptors, AM251 and the cannabinoid receptor agonists, Δ(9)-tetrahydrocannabinol (THC), cannabidiol, anandamide, and WIN 55,212-2. Relationships were determined between cannabinoid concentration and respiratory rate driven by substrates of complex I, II or IV in pig brain mitochondria. Either full or partial inhibition of respiratory rate was found for the tested drugs, with an IC50 in the micromolar range, which verified the significant role of non-receptor-mediated mechanism in inhibiting mitochondrial respiration. Effect of stepwise application of THC and AM251 evidenced protective role of AM251 and corroborated the participation of CB1 receptor activation in the inhibition of mitochondrial respiration. We proposed a model, which includes both receptor- and non-receptor-mediated mechanisms of cannabinoid action on mitochondrial respiration. This model explains both the inhibitory effect of cannabinoids and the protective effect of the CB1 receptor inverse agonist.

  7. Bundvands respiration i Kattegat og Bælthavet

    DEFF Research Database (Denmark)

    Hansen, Jørgen L. S.; Bendtsen, Jørgen

    Der findes generelt meget få direkte målinger af den pelagiske respiration, og det har ikke været muligt at finde repræsentative målinger af den pelagiske respiration for de åbne danske farvande. Her præsenteres et sæsonstudie af bundvandets respiration fra 5 stationer i et transekt gående fra det....... Temperaturfølsomheden af respirationsraten udtrykt som en Q10 var 3,01 ± 1.07 for alle forsøg og uafhængigt af om prøverne blev kølet eller opvarmet under inkubationerne. Den labile pulje af organisk stof blev bestemt og de observerede respirations rater svarede til specifikke kulstof omsætningsrater på mellem 0...... målbar reduktion i det partikulære materiale under inkubationerne, tyder overraskende på,at opløst organisk materiale (DOM) er den vigtigste kulstofkilde for bundvandet respiration....

  8. Assessment of respiration activity and ecotoxicity of composts containing biopolymers.

    Science.gov (United States)

    Kopeć, Michał; Gondek, Krzysztof; Baran, Agnieszka

    2013-03-01

    The research was conducted to determine if introducing biodegradable polymer materials to the composting process would affect selected biological properties of mature compost. Determination of biological properties of composts composed of testing their respiration activity and toxicity. Respiration activity was measured in material from the composting process by means of OxiTop Control measuring system. The ecotoxicity of composts was estimated by means of a set of biotests composed of three microbiotests using five test organisms. Introduction of polymer materials caused a decrease in respiration activity of mature compost. Similar dependencies as in the case of mass loss were registered. Compost to which a biodegradable polymer with the highest content of starch was added revealed the smallest difference in comparison with organic material composted without polymers. Lower content of starch in a polymer caused lower respiration activity of composts, whereas microorganism vaccine might have accelerated maturing of composts, thus contributing to the smallest respiration of compost. In composts containing biopolymers the following were observed: an increase in germination inhibition--2.5 times, roots growth inhibition--1.8 times, growth inhibition of Heterocypris incongruens--four times and luminescence inhibition of Vibrio fischeri--1.6 times in comparison with the control (compost K1). Composts containing biopolymers were classified as toxicity class III, whereas the compost without polymer addition as class II.

  9. Exposure to inhalable, respirable, and ultrafine particles in welding fume.

    Science.gov (United States)

    Lehnert, Martin; Pesch, Beate; Lotz, Anne; Pelzer, Johannes; Kendzia, Benjamin; Gawrych, Katarzyna; Heinze, Evelyn; Van Gelder, Rainer; Punkenburg, Ewald; Weiss, Tobias; Mattenklott, Markus; Hahn, Jens-Uwe; Möhlmann, Carsten; Berges, Markus; Hartwig, Andrea; Brüning, Thomas

    2012-07-01

    This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m(-3) for inhalable and 1.29 mg m(-3) for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m(-3)). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements welding fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging.

  10. Breathing simulator of workers for respirator performance test.

    Science.gov (United States)

    Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

    2015-01-01

    Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

  11. The effect of outside conditions on anaerobic ammonia oxidation reaction

    Institute of Scientific and Technical Information of China (English)

    YANG Min; WANG Shu-bo

    2016-01-01

    Organic carbon, inorganic carbon, temperature, pH and ORP are all to have a certain influence on the anaerobic ammonia oxidation reaction. We can draw some conclusions on the optimum conditions of anaerobic ammonia oxidation reaction. The optimum temperature of the anaerobic ammonia oxidation reaction is 30-35℃. And the optimum pH of the anaerobic ammonia reaction is 7.5-8.3. The presence of organic matters can affect the anaerobic ammonia reaction, and different organic matters have different influence on it. The concentration of the inorganic carbon also exist great influence on the reaction. High inorganic carbon concentration also can inhibit anaerobic ammonia oxidation reaction.

  12. A Diverse Community of Metal(loid) Oxide Respiring Bacteria Is Associated with Tube Worms in the Vicinity of the Juan de Fuca Ridge Black Smoker Field.

    Science.gov (United States)

    Maltman, Chris; Walter, Graham; Yurkov, Vladimir

    2016-01-01

    Epibiotic bacteria associated with tube worms living in the vicinity of deep sea hydrothermal vents of the Juan de Fuca Ridge in the Pacific Ocean were investigated for the ability to respire anaerobically on tellurite, tellurate, selenite, selenate, metavanadate and orthovanadate as terminal electron acceptors. Out of 107 isolates tested, 106 were capable of respiration on one or more of these oxides, indicating that metal(loid) oxide based respiration is not only much more prevalent in nature than is generally believed, but also is an important mode of energy generation in the habitat. Partial 16S rRNA gene sequencing revealed the bacterial community to be rich and highly diverse, containing many potentially new species. Furthermore, it appears that the worms not only possess a close symbiotic relationship with chemolithotrophic sulfide-oxidizing bacteria, but also with the metal(loid) oxide transformers. Possibly they protect the worms through reduction of the toxic compounds that would otherwise be harmful to the host.

  13. A Diverse Community of Metal(loid Oxide Respiring Bacteria Is Associated with Tube Worms in the Vicinity of the Juan de Fuca Ridge Black Smoker Field.

    Directory of Open Access Journals (Sweden)

    Chris Maltman

    Full Text Available Epibiotic bacteria associated with tube worms living in the vicinity of deep sea hydrothermal vents of the Juan de Fuca Ridge in the Pacific Ocean were investigated for the ability to respire anaerobically on tellurite, tellurate, selenite, selenate, metavanadate and orthovanadate as terminal electron acceptors. Out of 107 isolates tested, 106 were capable of respiration on one or more of these oxides, indicating that metal(loid oxide based respiration is not only much more prevalent in nature than is generally believed, but also is an important mode of energy generation in the habitat. Partial 16S rRNA gene sequencing revealed the bacterial community to be rich and highly diverse, containing many potentially new species. Furthermore, it appears that the worms not only possess a close symbiotic relationship with chemolithotrophic sulfide-oxidizing bacteria, but also with the metal(loid oxide transformers. Possibly they protect the worms through reduction of the toxic compounds that would otherwise be harmful to the host.

  14. Principles and potential of the anaerobic digestion of waste-activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Appels, Lise; Degreve, Jan [Department of Chemical Engineering, Katholieke Universiteit Leuven, W. De Croylaan 46, B-3001 Heverlee (Belgium); Baeyens, Jan [Department of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Dewil, Raf [Department of Chemical Engineering, Katholieke Universiteit Leuven, W. De Croylaan 46, B-3001 Heverlee (Belgium); Department of Chemical Engineering, Associated Faculty of Technology and Biosciences, Campus De Nayer, Katholieke Universiteit Leuven, Jan De Nayerlaan 5, B-2860 Sint-Katelijne-Waver (Belgium)

    2008-12-15

    When treating municipal wastewater, the disposal of sludge is a problem of growing importance, representing up to 50% of the current operating costs of a wastewater treatment plant. Although different disposal routes are possible, anaerobic digestion plays an important role for its abilities to further transform organic matter into biogas (60-70 vol% of methane, CH{sub 4}), as thereby it also reduces the amount of final sludge solids for disposal whilst destroying most of the pathogens present in the sludge and limiting odour problems associated with residual putrescible matter. Anaerobic digestion thus optimises WWTP costs, its environmental footprint and is considered a major and essential part of a modern WWTP. The potential of using the biogas as energy source has long been widely recognised and current techniques are being developed to upgrade quality and to enhance energy use. The present paper extensively reviews the principles of anaerobic digestion, the process parameters and their interaction, the design methods, the biogas utilisation, the possible problems and potential pro-active cures, and the recent developments to reduce the impact of the problems. After having reviewed the basic principles and techniques of the anaerobic digestion process, modelling concepts will be assessed to delineate the dominant parameters. Hydrolysis is recognised as rate-limiting step in the complex digestion process. The microbiology of anaerobic digestion is complex and delicate, involving several bacterial groups, each of them having their own optimum working conditions. As will be shown, these groups are sensitive to and possibly inhibited by several process parameters such as pH, alkalinity, concentration of free ammonia, hydrogen, sodium, potassium, heavy metals, volatile fatty acids and others. To accelerate the digestion and enhance the production of biogas, various pre-treatments can be used to improve the rate-limiting hydrolysis. These treatments include

  15. Oxidation catalysts on alkaline earth supports

    Energy Technology Data Exchange (ETDEWEB)

    Mohajeri, Nahid

    2017-03-21

    An oxidation catalyst includes a support including particles of an alkaline earth salt, and first particles including a palladium compound on the support. The oxidation catalyst can also include precious metal group (PMG) metal particles in addition to the first particles intermixed together on the support. A gas permeable polymer that provides a continuous phase can completely encapsulate the particles and the support. The oxidation catalyst may be used as a gas sensor, where the first particles are chemochromic particles.

  16. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

    Energy Technology Data Exchange (ETDEWEB)

    John R. Gallagher

    2001-07-31

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

  17. Chemical reactivity of {alpha}-isosaccharinic acid in heterogeneous alkaline systems

    Energy Technology Data Exchange (ETDEWEB)

    Glaus, M. A.; Loon, L. R. Van

    2009-05-15

    Cellulose degradation under alkaline conditions is of relevance for the mobility of many radionuclides in the near-field of a cementitious repository for radioactive waste, because metal-binding degradation products may be formed. Among these, {alpha}- isosaccharinic acid ({alpha}-ISA) is the strongest complexant. The prediction of the equilibrium concentration of {alpha}-ISA in cement pore water is therefore an important step in the assessment of the influence of cellulose degradation products on the speciation of radionuclides in such environments. The present report focuses on possible chemical transformation reactions of {alpha}-ISA in heterogeneous alkaline model systems containing either Ca(OH){sub 2} or crushed hardened cement paste. The transformation reactions were monitored by measuring the concentration of {alpha}-ISA by high performance anion exchange chromatography and the formation of reaction products by high performance ion exclusion chromatography. The overall loss of organic species from solution was monitored by measuring the concentration of non-purgeable organic carbon. The reactions were examined in diluted and compacted suspensions, at either 25 {sup o}C or 90 {sup o}C, and under anaerobic atmospheres obtained by various methods. It was found that {alpha}-ISA was transformed under all conditions tested to some extent. Reaction products, such as glycolate, formate, lactate and acetate, all compounds with less complexing strength than {alpha}-ISA, were detected. The amount of reaction products identified by the chromatographic technique applied was {approx} 50 % of the amount of {alpha}-ISA reacted. Sorption of {alpha}-ISA to Ca(OH){sub 2} contributed only to a minor extent to the loss of {alpha}-ISA from the solution phase. As the most important conclusion of the present work it was demonstrated that the presence of oxidising agents had a distinctive influence on the turnover of {alpha}-ISA. Under aerobic conditions {alpha}-ISA was

  18. Oxygen Effects in Anaerobic Digestion - II

    Directory of Open Access Journals (Sweden)

    Deshai Botheju

    2010-04-01

    Full Text Available Standard models describing bio-gasification using anaerobic digestion do not include necessary processes to describe digester dynamics under the conditions of oxygen presence. Limited oxygenation in anaerobic digestion can sometimes be beneficial. The oxygen effects included anaerobic digestion model, ADM 1-Ox, was simulated against experimental data obtained from laboratory scale anaerobic digesters operated under different oxygenation conditions. ADM 1-Ox predictions are generally in good agreement with the trends of the experimental data. ADM 1-Ox simulations suggest the existence of an optimum oxygenation level corresponding to a peak methane yield. The positive impact of oxygenation on methane yield is more pronounced at conditions characterized by low hydrolysis rate coefficients (slowly degradable feed and low biomass concentrations. The optimum oxygenation point moves towards zero when the hydrolysis rate coefficient and the biomass concentration increase. Accordingly, the impact of oxygenation on methane yield can either be positive or negative depending on the digestion system characteristics. The developed ADM 1-Ox model can therefore be a valuable tool for recognizing suitable operating conditions for achieving the maximum benefits from partial aeration in anaerobic digestion.

  19. Effect of carbonate chemistry manipulations on calcification, respiration, and excretion of a Mediterranean pteropod

    Directory of Open Access Journals (Sweden)

    S. Comeau

    2012-05-01

    Full Text Available Although shelled pteropods are expected to be particularly sensitive to ocean acidification, the few available studies have mostly focused on polar species and have not allowed determining which parameter of the carbonate system controls their calcification. Specimens of the temperate Mediterranean species Creseis acicula were maintained under seven different conditions of the carbonate chemistry, obtained by manipulating pH and total alkalinity, with the goal to disentangle the effects of the pH and the saturation state with respect to aragonite (Ωa. Our results tend to show that respiration, excretion as well as rates of net and gross calcification were not directly affected by a decrease in pH but decreased significantly with a decrease in Ωa. Due to the difficulties in maintaining pteropods in the laboratory and the important variability in their abundances in our study site, long-term acclimation as well as replication of the experiment was not possible. However, we strongly believe that these results represent an important step in the mechanistic understanding of the effect of ocean acidification on pteropods physiology.

  20. Evaluation of Respirable Crystalline Silica in High School Ceramics Classrooms

    Directory of Open Access Journals (Sweden)

    Matthew Fechser

    2014-01-01

    Full Text Available Air concentrations of respirable crystalline silica were measured in eleven (11 high school ceramics classrooms located in Salt Lake County, UT, USA. Respirable dust was collected on PVC filters using precision flow pumps and cyclone samplers (n = 44. Filters were subsequently analyzed for respirable dust and percent crystalline silica content. The geometric mean of the silica concentrations was 0.009 mg/m3 near the teacher’s work station and 0.008 mg/m3 near the kilns. The number of students in the classroom was correlated to the silica concentration in the ceramics classroom, but no correlation was found between the silica concentrations and either the size of the classroom or the age of the building. Results from this study indicate that ceramics teachers may be at an increased risk of exposure to crystalline silica based on the ACGIH TLV of 0.025 mg/m3, with an exceedance of 21%.

  1. Evaluation of Respirable Crystalline Silica in High School Ceramics Classrooms

    Science.gov (United States)

    Fechser, Matthew; Alaves, Victor; Larson, Rodney; Sleeth, Darrah

    2014-01-01

    Air concentrations of respirable crystalline silica were measured in eleven (11) high school ceramics classrooms located in Salt Lake County, UT, USA. Respirable dust was collected on PVC filters using precision flow pumps and cyclone samplers (n = 44). Filters were subsequently analyzed for respirable dust and percent crystalline silica content. The geometric mean of the silica concentrations was 0.009 mg/m3 near the teacher’s work station and 0.008 mg/m3 near the kilns. The number of students in the classroom was correlated to the silica concentration in the ceramics classroom, but no correlation was found between the silica concentrations and either the size of the classroom or the age of the building. Results from this study indicate that ceramics teachers may be at an increased risk of exposure to crystalline silica based on the ACGIH TLV of 0.025 mg/m3, with an exceedance of 21%. PMID:24464235

  2. Indoor-outdoor relationships of respirable sulfates and particles

    Science.gov (United States)

    Dockery, Douglas W.; Spengler, John D.

    Indoor and outdoor concentrations of respirable particulates and sulfates have been measured in 68 homes in six cities for at least 1 yr. A conservation of mass model was derived describing indoor concentrations in terms of outdoor concentrations, infiltration and indoor sources. The measured data were analysed to identify important building characteristics and to quantify their effect. The mean infiltration rate of outdoor fine particulates was found to be approximately 70%. Cigarette smoking was found to be the dominant indoor source of respirable particulates. Increased indoor concentrations of sulfates were found to be associated with smoking and also with gas stoves. The effect of full air conditioning of the building was to reduce infiltration of outdoor fine particulates by about one half, while preventing dilution and purging of internally generated pollutants. The model for indoor respirable particulate and sulfate levels was found to compare well with measurements.

  3. The Path of Carbon in Photosynthesis VII. Respiration and Photosynthesis

    Science.gov (United States)

    Benson, A. A.; Calvin, M.

    1949-07-21

    The relationship of respiration to photosynthesis in barley seedling leaves and the algae, Chlorella and Scenedesmus, has been investigated using radioactive carbon dioxide and the techniques of paper chromatography and radioautography. The plants are allowed to photosynthesize normally for thirty seconds in c{sup 14}O{sub 2} after which they are allowed to respire in air or helium in the light or dark. Respiration of photosynthetic intermediates as evidenced by the appearance of labeled glutomic, isocitric, fumaric and succinic acids is slower in the light than in the dark. Labeled glycolic acid is observed in barley and algae. It disappears rapidly in the dark and is maintained and increased in quantity in the light in C0{sub 2}-free air.

  4. Growth and respiration of regenerating tissues of the axolotl tail.

    Science.gov (United States)

    Vladimirova, I G

    1975-01-01

    Changes in the weight and oxygen consumption were studied during regeneration of the tail in adult axolotls and larvae. The curve of the increase in weight of the regenerating tail in both age groups is S-shaped. The intensity of respiration of the regenerating tail increases in adult axolotls and in larvae at the blastema stage; in adult axolotls there is also a second increase in the intensity of respiration of the regenerating tail during differentiation of the muscles. The relationship between weight and the rate of respiration was compared during regeneration of the tail in axolotl and the normal growth of the animals. Whereas growth of the animals was characterized by the relationship QO2 equals aPk with a constant value of k, during regeneration the various stages of this process have their own corresponding values of k.

  5. Cyanide-insensitive respiration in Acanthamoeba castellanii. Changes in sensitivity of whole cell respiration during exponential growth

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, S.W.; Lloyd, D.

    1977-01-01

    Respiration of Acanthamoeba castellanii shows varying sensitivity to cyanide during exponential growth in a medium containing proteose peptone, glucose and yeast extract. After 20 h growth, respiration was stimulated up to 40% by I mM-cyanide; sensitivity to cyanide then gradually increased until 90% inhibition of respiration was attained in late exponential phase cultures. Salicyl hydroxamic acid alone never stimulated or inhibited respiration by more than 20% but, when added together with cyanide, inhibition was always 70 to 100% from 3 h onward. Sensitivity to antimycin A was similar, but not identical to that shown to cyanide; when antimycin A was added together with salicyl hydroxamic acid, the inhibition was greater. Increased sensitivities to arsenite and malonate were also observed in late-exponential phase cultures. These changes in sensitivities were not associated with alterations in the growth medium since similar changes in sensitivity to inhibitors were observed during growth in conditioned medium. A rotenone-sensitive site is associated with cyanide-stimulated respiration and the results suggest that A. castellanii possesses a branched electron transport system.

  6. Alkaline and ultrasound assisted alkaline pretreatment for intensification of delignification process from sustainable raw-material.

    Science.gov (United States)

    Subhedar, Preeti B; Gogate, Parag R

    2014-01-01

    Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.

  7. [Anaerobic reduction of humus/Fe (III) and electron transport mechanism of Fontibacter sp. SgZ-2].

    Science.gov (United States)

    Ma, Chen; Yang, Gui-qin; Lu, Qin; Zhou, Shun-gui

    2014-09-01

    Humus and Fe(III) respiration are important extracellular respiration metabolism. Electron transport pathway is the key issue of extracellular respiration. To understand the electron transport properties and the environmental behavior of a novel Fe(III)- reducing bacterium, Fontibacter sp. SgZ-2, capacities of anaerobic humus/Fe(III) reduction and electron transport mechanisms with four electron acceptors were investigated in this study. The results of anaerobic batch experiments indicated that strain SgZ-2 had the ability to reduce humus analog [ 9,10-anthraquinone-2,6-disulfonic acid (AQDS) and 9,10-anthraquinone-2-sulfonic acid (AQS)], humic acids (HA), soluble Fe(III) (Fe-EDTA and Fe-citrate) and Fe(III) oxides [hydrous ferric oxide (HFO)]. Fermentative sugars (glucose and sucrose) were the most effective electron donors in the humus/Fe(III) reduction by strain SgZ-2. Additionally, differences of electron carrier participating in the process of electron transport with different electron acceptors (i. e. , oxygen, AQS, Fe-EDTA and HFO) were investigated using respiratory inhibitors. The results suggested that similar respiratory chain components were involved in the reducing process of oxygen and Fe-EDTA, including dehydrogenase, quinones and cytochromes b-c. In comparison, only dehydrogenase was found to participate in the reduction of AQS and HFO. In conclusion, different electron transport pathways may be employed by strain SgZ-2 between insoluble and soluble electron acceptors or among soluble electron acceptors. Preliminary models of electron transport pathway with four electron acceptors were proposed for strain SgZ-2, and the study of electron transport mechanism was explored to the genus Fontibacter. All the results from this study are expected to help understand the electron transport properties and the environmental behavior of the genus Fontibacter.

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

    Science.gov (United States)

    Tremaine, Mary; Hebert, Alexander S.; Myers, Kevin S.; Sardi, Maria; Dickinson, Quinn; Reed, Jennifer L.; Zhang, Yaoping; Coon, Joshua J.; Hittinger, Chris Todd; Gasch, Audrey P.; Landick, Robert

    2016-01-01

    The inability of native Saccharomyces cerevisiae to convert xylose from plant biomass into biofuels remains a major challenge for the production of renewable bioenergy. Despite extensive knowledge of the regulatory networks controlling carbon metabolism in yeast, little is known about how to reprogram S. cerevisiae to ferment xylose at rates comparable to glucose. Here we combined genome sequencing, proteomic profiling, and metabolomic analyses to identify and characterize the responsible mutations in a series of evolved strains capable of metabolizing xylose aerobically or anaerobically. We report that rapid xylose conversion by engineered and evolved S. cerevisiae strains depends upon epistatic interactions among genes encoding a xylose reductase (GRE3), a component of MAP Kinase (MAPK) signaling (HOG1), a regulator of Protein Kinase A (PKA) signaling (IRA2), and a scaffolding protein for mitochondrial iron-sulfur (Fe-S) cluster biogenesis (ISU1). Interestingly, the mutation in IRA2 only impacted anaerobic xylose consumption and required the loss of ISU1 function, indicating a previously unknown connection between PKA signaling, Fe-S cluster biogenesis, and anaerobiosis. Proteomic and metabolomic comparisons revealed that the xylose-metabolizing mutant strains exhibit altered metabolic pathways relative to the parental strain when grown in xylose. Further analyses revealed that interacting mutations in HOG1 and ISU1 unexpectedly elevated mitochondrial respiratory proteins and enabled rapid aerobic respiration of xylose and other non-fermentable carbon substrates. Our findings suggest a surprising connection between Fe-S cluster biogenesis and signaling that facilitates aerobic respiration and anaerobic fermentation of xylose, underscoring how much remains unknown about the eukaryotic signaling systems that regulate carbon metabolism. PMID:27741250

  9. Determination of pressure drop across activated carbon fiber respirator cartridges.

    Science.gov (United States)

    Balanay, Jo Anne G; Lungu, Claudiu T

    2016-01-01

    Activated carbon fiber (ACF) is considered as an alternative adsorbent to granular activated carbon (GAC) for the development of thinner, lighter, and efficient respirators because of their larger surface area and adsorption capacities, thinner critical bed depth, lighter weight, and fabric form. This study aims to measure the pressure drop across different types of commercially available ACFs in respirator cartridges to determine the ACF composition and density that will result in acceptably breathable respirators. Seven ACF types in cloth (ACFC) and felt (ACFF) forms were tested. ACFs in cartridges were challenged with pre-conditioned constant air flow (43 LPM, 23°C, 50% RH) at different compositions (single- or combination-ACF type) in a test chamber. Pressure drop across ACF cartridges were obtained using a micromanometer, and compared among different cartridge configurations, to those of the GAC cartridge, and to the NIOSH breathing resistance requirements for respirator cartridges. Single-ACF type cartridges filled with any ACFF had pressure drop measurements (23.71-39.93 mmH2O) within the NIOSH inhalation resistance requirement of 40 mmH2O, while those of the ACFC cartridges (85.47±3.67 mmH2O) exceeded twice the limit due possibly to the denser weaving of ACFC fibers. All single ACFF-type cartridges had higher pressure drop compared to the GAC cartridge (23.13±1.14 mmH2O). Certain ACF combinations (2 ACFF or ACFC/ACFF types) resulted to pressure drop (26.39-32.81 mmH2O) below the NIOSH limit. All single-ACFF type and all combination-ACF type cartridges with acceptable pressure drop had much lower adsorbent weights than GAC (≤15.2% of GAC weight), showing potential for light-weight respirator cartridges. 100% ACFC in cartridges may result to respirators with high breathing resistance and, thus, is not recommended. The more dense ACFF and ACFC types may still be possibly used in respirators by combining them with less dense ACFF materials and/or by

  10. Fundamental Medical and Engineering Investigations on Protective Artificial Respiration

    CERN Document Server

    Klaas, Michael; Schroder, Wolfgang

    2011-01-01

    This volume contains a collection of papers from the research program 'Protective Artificial Respiration (PAR)'. In 2005 the German Research Association DFG launched the research program PAR which is a joint initiative of medicine and fluid mechanics. The main long-term objective of this program is the development of a more protective artificial respiratory system to reduce the physical stress of patients undergoing artificial respiration. To satisfy this goal 11 projects have been defined. In each of these projects scientists from medicine and fluid mechanics do collaborate in several experim

  11. Antoine Lavoisier and the study of respiration: 200 years old.

    Science.gov (United States)

    Stokes, M A

    1991-03-01

    Antoine Lavoisier has been called the father of modern chemistry. From a medical point of view, he introduced the study of respiration and metabolism and so founded biochemistry. With his experiments, our knowledge of how the body works made immense strides forward. Two hundred years ago, he wrote his last authentic and untouched account of his views on respiration, in a letter to Joseph Black in Edinburgh. This opportunity has been taken to briefly review this work and the life of a man who did much to improve our understanding of ourselves.

  12. Anaerobic lipid degradation through acidification and methanization.

    Science.gov (United States)

    Kim, Ijung; Kim, Sang-Hyoun; Shin, Hang-Sik; Jung, Jin-Young

    2010-01-01

    In biological wastewater treatment high lipid concentration is known to inhibit microorganisms and cause active biomass flotation. To reduce lipid inhibition, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor, was applied to synthetic dairy wastewater. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid and volatile fatty acid (VFA) removal efficiencies were more than 80%, 70% and 95%, respectively, up to organic loading rate 6.5 g COD/L/day. There were no operational problems such as serious scum formation or sludge washout. Protein degradation occurred prior to degradation during acidogenesis.

  13. Biochemistry and physiology of anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-18

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

  14. Kinetics and modeling of anaerobic digestion process

    DEFF Research Database (Denmark)

    2003-01-01

    Anaerobic digestion modeling started in the early 1970s when the need for design and efficient operation of anaerobic systems became evident. At that time not only was the knowledge about the complex process of anaerobic digestion inadequate but also there were computational limitations. Thus......, the first models were very simple and consisted of a limited number of equations. During the past thirty years much research has been conducted on the peculiarities of the process and on the factors that influence it on the one hand while an enormous progress took place in computer science on the other....... The combination of both parameters resulted in the development of more and more concise and complex models. In this chapter the most important models found in the literature are described starting from the simplest and oldest to the more recent and complex ones....

  15. Multivariate monitoring of anaerobic co-digestion

    DEFF Research Database (Denmark)

    Madsen, Michael; Holm-Nielsen, Jens Bo

    Anaerobic digestion processes for production of renewable energy in the form of biogas, and in the future hydrogen, are becoming increasingly important worldwide. Sustainable solutions for renewable energy production systems are given high political priority, amongst other things due to global...... warming and environmental concerns. Anaerobic digestion applied in agriculture can simultaneously convert heterogeneous biomasses and wastes from the primary agricultural sector and from the bio processing industries, for instance food processing, pharma, and biofuel production, into valuable organic...... fertiliser and renewable energy. Meanwhile, in order for the biogas sector to become a significant player in the energy supply chain, the anaerobic digestion process has to be controlled to a greater extent than what is implemented as state-of-the-art today. Through application of the philosophy behind...

  16. The effect of tannic compounds on anaerobic wastewater treatment.

    NARCIS (Netherlands)

    Field, J.A.

    1989-01-01

    Anaerobic wastewater treatment is an alternative to the conventional aerobic treatment processes for the removal of easily biodegradable organic matter in medium to high strength industrial wastestreams. Anaerobic treatment has several advantages, however one important disadvantage is the high sensi

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  18. Surfactant-enhanced alkaline flooding: Buffering at intermediate alkaline pH

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, J.; Wasan, D.T. (Illinois Inst. of Tech., Chicago, IL (United States))

    1993-11-01

    The alkaline flooding process involves injecting alkaline agents into the reservoir to produce more oil than is produced through conventional waterflooding. The interaction of the alkali in the flood water with the naturally occurring acids in the reservoir oil results in in-situ formation of soaps, which are partially responsible for lowering IFT and improving oil recovery. The extent to which IFT is lowered depends on the specific oil and injection water properties. Numerous investigators have attempted to clarify the relationship between system chemical composition and IFT. An experimental investigation of buffered alkaline flooding system chemistry was undertaken to determine the influence of various species present on interfacial tension (IFT) as a function of pH and ionic strength. IFT was found to go through an ultralow minimum in certain pH ranges. This synergism results from simultaneous adsorption of un-ionized and ionized acid species on the interface.

  19. Robust regulation of anaerobic digestion processes.

    Science.gov (United States)

    Mailleret, L; Bernard, O; Steyer, J P

    2003-01-01

    This paper deals with the problem of controlling anaerobic digestion processes. A two-step (i.e. acidogenesis-methanization) mass balance model is considered for a 1 m3 fixed bed digester treating industrial wine distillery wastewater. The control law aims at regulating the organic pollution level while avoiding washout of biomass. To this end, a simple output feedback controller is considered which regulates a variable strongly related to the Chemical Oxygen Demand (COD). Numerical simulations assuming noisy measurements first illustrate the robustness of this control procedure. Then, the regulating procedure is implemented on the considered anaerobic digestion process in order to validate and demonstrate its efficiency in real life experiments.

  20. Anaerobic bacteria, the colon and colitis.

    Science.gov (United States)

    Roediger, W E

    1980-02-01

    Anaerobic bacteria constitute more than 90% of the bacteria in the colon. An anaerobic environment is needed to maintain their growth and the production of short-chain fatty acids by these bacteria from carbohydrates. Short-chain fatty acids are rapidly absorbed and essential for metabolic as well as functional welfare of the colonic mucosa. The importance of these acids in water absorption and in the patogenesis of colitis is discussed in relation to the concept of "energy deficiency diseases" of the colonic mucosa.

  1. The Pasteur effect in facultative anaerobic metazoa.

    Science.gov (United States)

    Schmidt, H; Kamp, G

    1996-05-15

    The existence and the regulatory mechanisms of the Pasteur effect in facultative anaerobic metazoa are discussed. There are three reasons for the controversy surrounding this phenomenon. 1) The different definitions of the Pasteur effect, 2) the antagonistic effect of metabolic depression and its species specific response to hypoxia, as well as 3) the laboratory-specific differences in the experimental procedures for analyzing the Pasteur effect and its regulation. This review aims to clarify the confusion about the existence of the Pasteur effect in facultative anaerobic metazoa and to offer possible molecular mechanisms.

  2. Trace elements induce predominance among methanogenic activity in anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Babett Wintsche

    2016-12-01

    Full Text Available Trace elements play an essential role in all organisms due to their functions in enzyme complexes. In anaerobic digesters, control and supplementation of trace elements lead to stable and more efficient methane production processes while trace element deficits cause process imbalances. However, the underlying metabolic mechanisms and the adaptation of the affected microbial communities to such deficits are not yet fully understood. Here, we investigated the microbial community dynamics and resulting process changes induced by trace element deprivation. Two identical lab-scale continuous stirred tank reactors fed with distiller’s grains and supplemented with trace elements (cobalt, molybdenum, nickel, tungsten and a commercial iron additive were operated in parallel. After 72 weeks of identical operation, the feeding regime of one reactor was changed by omitting trace element supplements and reducing the amount of iron additive. Both reactors were operated for further 21 weeks. Various process parameters (biogas production and composition, total solids and volatile solids, trace element concentration, volatile fatty acids, total ammonium nitrogen, total organic acids/alkalinity ratio, and pH and the composition and activity of the microbial communities were monitored over the total experimental time. While the methane yield remained stable, the concentrations of hydrogen sulfide, total ammonia nitrogen, and acetate increased in the trace element-depleted reactor compared to the well-supplied control reactor. Methanosarcina and Methanoculleus dominated the methanogenic communities in both reactors. However, the activity ratio of these two genera was shown to depend on trace element supplementation explainable by different trace element requirements of their energy conservation systems. Methanosarcina dominated the well-supplied anaerobic digester, pointing to acetoclastic methanogenesis as the dominant methanogenic pathway. Under trace element

  3. A novel electrophototrophic bacterium Rhodopseudomonas palustris strain RP2, exhibits hydrocarbonoclastic potential in anaerobic environments

    Directory of Open Access Journals (Sweden)

    Krishnaveni Venkidusamy

    2016-07-01

    Full Text Available An electrophototrophic, hydrocarbonoclastic bacterium Rhodopseudomonas palustris stain RP2 was isolated from the anodic biofilms of hydrocarbon fed microbial electrochemical remediation systems (MERS. Salient properties of the strain RP2 were direct electrode respiration, dissimilatory metal oxide reduction, spore formation, anaerobic nitrate reduction, free living diazotrophy and the ability to degrade n-alkane components of petroleum hydrocarbons in anoxic, photic environments. In acetate fed microbial electrochemical cells, a maximum current density of 305±10 mA/m2 (1000Ω was generated (power density 131.65±10 mW/m2 by strain RP2 with a coulombic efficiency of 46.7 ± 1.3%. Cyclic voltammetry studies showed that anaerobically grown cells of strain RP2 is electrochemically active and likely to transfer electrons extracellularly to solid electron acceptors through membrane bound compounds, however, aerobically grown cells lacked the electrochemical activity. The ability of strain RP2 to produce current (maximum current density 21±3 mA/m2; power density 720±7 µW/m2, 1000Ω using petroleum hydrocarbon (PH as a sole energy source was also examined using an initial concentration of 800 mg l-1 of diesel range hydrocarbons (C9- C36 with a concomitant removal of 47.4 ± 2.7% hydrocarbons in MERS. Here, we also report the first study that shows an initial evidence for the existence of a hydrocarbonoclastic behavior in the strain RP2 when grown in different electron accepting and illuminated conditions (anaerobic and MERS degradation. Such observations reveal the importance of photoorganotrophic growth in the utilization of hydrocarbons from contaminated environments. Identification of such novel petrochemical hydrocarbon degrading electricigens, not only expands the knowledge on the range of bacteria known for the hydrocarbon bioremediation but also shows a biotechnological potential that goes well beyond its applications to MERS.

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

    Science.gov (United States)

    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…

  5. Stability of anaerobic reactors under micro-aeration conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Polanco, M.; Perez, S.; Diaz, I.; Fernandez-Polanco, F.

    2009-07-01

    Oxidation of sulphide in anaerobic bioreactors by introducing limited amounts of oxygen provides a relatively simple strategy for reducing the levels of sulphite in anaerobic digesters (biogas and effluent). The introduction of limited amounts of air is a general practice in agricultural anaerobic digesters, it is estimated that worldwide over 3.000 units are operated under such conditions. (Author)

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

    Science.gov (United States)

    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…

  7. Modelling hydraulic transport and anaerobic uptake by PAOs and GAOs during wastewater feeding in EBPR granular sludge reactors.

    Science.gov (United States)

    Weissbrodt, David G; Holliger, Christof; Morgenroth, Eberhard

    2017-03-21

    New-generation bioprocesses using granular sludge aim for a high-rate removal of nutrients from wastewater with low footprint. Achieving enhanced biological phosphorus removal (EBPR) relies on the design of sludge beds and wastewater feeding conditions to optimally load the biomass and to select for polyphosphate- (PAOs) over glycogen-accumulating organisms (GAOs) and other heterotrophs. A hydraulic-metabolic mathematical model was developed to elucidate the impact of hydraulic transport patterns and environmental conditions on the PAO/GAO competition during up-flow feeding through an EBPR granular sludge bed. Tracer experiments highlighted plug-flow regimes with dispersion under both rapid (9 m h(-1) , Rebed  = 1.6, Pez  = 7.2, Pet  = 4.6) and slow (0.9 m h(-1) , Rebed  = 0.2, Pez  = 21.3, Pet  = 3.4) feeding. Non-turbulent regimes (Rebed Feeding time, pH, and temperature significantly impacted bacterial competition for carbon uptake under anaerobic slow feeding. Feeding duration should be designed to avoid full depletion of intracellular storage polymers within static granules. PAOs bear twice longer feeding than GAOs by using both polyphosphate and glycogen hydrolysis to sustain anaerobic C-uptake. Alkaline conditions (pH 7.25-8.0) by, e.g., dosing lime in the feed select for PAOs independently of temperature (10 - 30°C). A twice higher bed is required for full anaerobic conversions at 10 rather than 20 °C. Biosystem responses for anaerobic C-uptake can be anticipated using the model toward designing robust anaerobic selectors to manage the microbial resource in EBPR granular sludge. This article is protected by copyright. All rights reserved.

  8. Strong Pasteur effect in rabbit corneal endothelium preserves fluid transport under anaerobic conditions.

    Science.gov (United States)

    Riley, M V; Winkler, B S

    1990-07-01

    1. The hydration and transparency of the mammalian cornea are maintained by a metabolically dependent fluid transport system located in the endothelial cell layer. The purpose of the study was to determine whether this pump activity is dependent upon aerobic or anaerobic metabolism. 2. The ability of the cornea, superfused in vitro with a bicarbonate-Ringer solution containing glucose and adenosine, to maintain normal hydration (thickness) when respiration is inhibited has been examined in intact and de-epithelialized preparations and correlated with glycolytic activity and cellular concentrations of ATP. 3. In respiring intact and de-epithelialized corneas thickness was maintained for periods up to 5 h during superfusion with the control Ringer solution. 4. KCN (10(-3) M) or antimycin A (10(-6) M) caused the intact cornea to swell at 15 +/- 3 microns h-1, whereas the de-epithelialized tissue maintained normal thickness under these conditions. This swelling of the intact tissue appears to be due to the osmotic effect of increased epithelial lactate production under anaerobic conditions. 5. Pre-swollen de-epithelialized corneas deturgesced fully to original thickness at a rate of 43 +/- 7 microns h-1 under aerobic conditions, but with KCN or antimycin they deturgesced at only 65% of that rate and generally failed to return to their original thickness. 6. Ouabain (10(-4) M) caused de-epithelialized corneas to swell in the presence of KCN or antimycin, as it did under aerobic conditions, showing that maintenance of hydration or deturgescence are pump-dependent processes under both conditions. 7. Lactate production was markedly stimulated by KCN or antimycin in intact and de-epithelialized preparations, but not in the stroma alone. The magnitude of the Pasteur effect was calculated to be 5-fold in the endothelium and 2.5-fold in the epithelium. Ouabain inhibited anaerobic lactate production in the endothelium by 50%. 8. ATP content of the epithelium following 5 h

  9. Alkaline carbonates in blast furnace process

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-10-01

    Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

  10. Estimating autotrophic respiration in streams using daily metabolism data

    Science.gov (United States)

    Knowing the fraction of gross primary production (GPP) that is immediately respired by autotrophs and their closely associated heterotrophs (ARf) is necessary to understand the trophic base and carbon spiraling in streams. We show a means to estimate ARf from daily metabolism da...

  11. Differential ventilation with spontaneous respiration for bilateral emphysema.

    Science.gov (United States)

    Chakravarthy, Murali; Jawali, Vivek

    2007-06-01

    In patients with bilateral bullous disease and empyema in one lung, controlled ventilation may be hazardous and result in severe hypoxia. A 50-year-old man with bullous disease and thoracic empyema on the left side was operated on under general anesthesia with spontaneous respiration using differential lung ventilation.

  12. 20 CFR 410.462 - Presumption relating to respirable disease.

    Science.gov (United States)

    2010-04-01

    ... AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Total Disability or Death Due to... will be presumed, in the absence of evidence to the contrary, that his death was due to pneumoconiosis arising out of employment in a coal mine. (b) Death will be found due to a respirable disease when...

  13. 78 FR 56273 - Occupational Exposure to Respirable Crystalline Silica

    Science.gov (United States)

    2013-09-12

    ... development of kidney and autoimmune diseases and in death from other nonmalignant respiratory diseases... September 12, 2013 Part II Department of Labor Occupational Safety and Health Administration 29 CFR Parts 1910, 1915, and 1926 Occupational Exposure to Respirable Crystalline Silica; Proposed Rule...

  14. Connecting Photosynthesis and Cellular Respiration: Preservice Teachers' Conceptions

    Science.gov (United States)

    Brown, Mary H.; Schwartz, Renee S.

    2009-01-01

    The biological processes of photosynthesis and plant cellular respiration include multiple biochemical steps, occur simultaneously within plant cells, and share common molecular components. Yet, learners often compartmentalize functions and specialization of cell organelles relevant to these two processes, without considering the interconnections…

  15. Ecophysiology and environmental distribution of organohalide-respiring bacteria

    NARCIS (Netherlands)

    Lu, Y.

    2016-01-01

    Organohalide-respiring bacteria (OHRB) are able to breathe natural and anthropogenically  produced organohalides persistent in a broad range of oxygen-depleted environments. Therefore, these microorganisms are of high interest for organohalide-contaminated site bioremediation and natural haloge

  16. ChillFish: A Respiration Game for Children with ADHD

    DEFF Research Database (Denmark)

    Sonne, Tobias; Jensen, Mads Møller

    and challenges of creating a tangible respiration-based controller and use it as a core game mechanic. Finally, we discuss the challenge of balancing engagement and relaxation in physically controlled games for children with ADHD in order to make a game that can be calming and still sustain their attention....

  17. Impact of some selected insecticides application on soil microbial respiration.

    Science.gov (United States)

    Latif, M A; Razzaque, M A; Rahman, M M

    2008-08-15

    The aim of present study was to investigate the impact of selected insecticides used for controlling brinjal shoot and fruit borer on soil microorganisms and to find out the insecticides or nontoxic to soil microorganism the impact of nine selected insecticides on soil microbial respiration was studied in the laboratory. After injection of different insecticides solutions, the soil was incubated in the laboratory at room temperature for 32 days. The amount of CO2 evolved due to soil microbial respiration was determined at 2, 4, 8, 16, 24 and 32 days of incubation. Flubendiamide, nimbicidine, lambda-cyhalothrin, abamectin and thiodicarb had stimulatory effect on microbial respiration during the initial period of incubation. Chlorpyriphos, cartap and carbosulfan had inhibitory effect on microbial respiration and cypermethrin had no remarkable effect during the early stage of incubation. The negative effect of chlorpyriphos, cartap and carbosulfan was temporary, which was disappeared after 4 days of insecticides application. No effect of the selected insecticides on soil microorganisms was observed after 24 or 32 days of incubation.

  18. Dynamical model development and parameter identification for an anaerobic wastewater treatment process.

    Science.gov (United States)

    Bernard, O; Hadj-Sadok, Z; Dochain, D; Genovesi, A; Steyer, J P

    2001-11-20

    This paper deals with the development and the parameter identification of an anaerobic digestion process model. A two-step (acidogenesis-methanization) mass-balance model has been considered. The model incorporates electrochemical equilibria in order to include the alkalinity, which has to play a central role in the related monitoring and control strategy of a treatment plant. The identification is based on a set of dynamical experiments designed to cover a wide spectrum of operating conditions that are likely to take place in the practical operation of the plant. A step by step identification procedure to estimate the model parameters is presented. The results of 70 days of experiments in a 1-m(3) fermenter are then used to validate the model.

  19. Monitoring methanogenic population dynamics in a full-scale anaerobic digester to facilitate operational management.

    Science.gov (United States)

    Williams, Julie; Williams, Haydn; Dinsdale, Richard; Guwy, Alan; Esteves, Sandra

    2013-07-01

    Microbial populations in a full-scale anaerobic digester fed on food waste were monitored over an 18-month period using qPCR. The digester exhibited a highly dynamic environment in which methanogenic populations changed constantly in response to availability of substrates and inhibitors. The methanogenic population in the digester was dominated by Methanosaetaceae, suggesting that aceticlastic methanogenesis was the main route for the production of methane. Sudden losses (69%) in Methanosaetaceae were followed by a build-up of VFAs which were subsequently consumed when populations recovered. A build up of ammonium inhibited Methanosaetaceae and resulted in shifts from acetate to hydrogen utilization. Addition of trace elements and alkalinity when propionate levels were high stimulated microbial growth. Routine monitoring of microbial populations and VFAs provided valuable insights into the complex processes occurring within the digester and could be used to predict digester stability and facilitate digester optimization.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mosey, F.E. [VFA Services Ltd., Herts (United Kingdom)

    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.

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

    DEFF Research Database (Denmark)

    Justesen, Tage; Justesen, Ulrik Stenz

    2013-01-01

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

  2. In situ respiration measurements of megafauna in the Kermadec Trench

    Science.gov (United States)

    Nunnally, Clifton C.; Friedman, Jason R.; Drazen, Jeffrey C.

    2016-12-01

    The aim of this paper is to measure metabolic rates of megafauna living in depths greater than 6000 m. Echinoderms, actinarians and a polychaete were captured by remotely operated vehicle (ROV) and inserted into respiration chambers in situ at depths of 4049 m, 7140 m and 8074 m in the region of the Kermadec Trench SW Pacific Ocean. Hadal research has moved into a new frontier as technological improvements now allow for a meticulous investigation of trench ecology in depths greater than 6000 m. The development of an in situ respirometer for use in these studies was deployed in the Kermadec Trench to obtain the first ever rates of basal metabolic rates of hadal megafauna. Typical deep-sea experiments of individual animal physiology must deal with covarying factors of pressure, temperature, light and food supply in this study investigated the effects of pressure and increased food supply on overall animal metabolism. In the Kermadec Trench, holothurian respiration rates (n=4), 0.079±0.011 (mean±SE) μmol-O2 g-1 h-1, were higher than those captured at abyssal depths (n=2), 0.018±0.002 μmol-O2 g-1h-1, in the same region (p<0.001). When Q10 adjusted to a common temperature of 2.5 °C trench holothurian respiration rates ranged between 0.068 and 0.119 μmol-O2 g-1 h-1. Anemone respiration rates were remarkably similar between abyssal and hadal specimens, 0.110 and 0.111 μmol-O2 g-1 h-1, respectively. Our results on echinoderm respiration when corrected for temperature and mass fall below the slope regression when compared with other in situ measurements at shallower ocean depths.

  3. Evaluation of respiration-correlated digital tomosynthesis in lung1

    Science.gov (United States)

    Santoro, Joseph; Kriminski, Sergey; Lovelock, D. Michael; Rosenzweig, Kenneth; Mostafavi, Hassan; Amols, Howard I.; Mageras, Gig S.

    2010-01-01

    Digital tomosynthesis (DTS) with a linear accelerator-mounted imaging system provides a means of reconstructing tomographic images from radiographic projections over a limited gantry arc, thus requiring only a few seconds to acquire. Its application in the thorax, however, often results in blurred images from respiration-induced motion. This work evaluates the feasibility of respiration-correlated (RC) DTS for soft-tissue visualization and patient positioning. Image data acquired with a gantry-mounted kilovoltage imaging system while recording respiration were retrospectively analyzed from patients receiving radiotherapy for non-small-cell lung carcinoma. Projection images spanning an approximately 30° gantry arc were sorted into four respiration phase bins prior to DTS reconstruction, which uses a backprojection, followed by a procedure to suppress structures above and below the reconstruction plane of interest. The DTS images were reconstructed in planes at different depths through the patient and normal to a user-selected angle close to the center of the arc. The localization accuracy of RC-DTS was assessed via a comparison with CBCT. Evaluation of RC-DTS in eight tumors shows visible reduction in image blur caused by the respiratory motion. It also allows the visualization of tumor motion extent. The best image quality is achieved at the end-exhalation phase of the respiratory motion. Comparison of RC-DTS with respiration-correlated cone-beam CT in determining tumor position, motion extent and displacement between treatment sessions shows agreement in most cases within 2–3 mm, comparable in magnitude to the intraobserver repeatability of the measurement. These results suggest the method’s applicability for soft-tissue image guidance in lung, but must be confirmed with further studies in larger numbers of patients. PMID:20384261

  4. EFFECTS OF ECCENTRIC EXERCISE ON ANAEROBIC POWER, STARTING SPEED AND ANAEROBIC ENDURANCE

    OpenAIRE

    Maciejczyk, Marcin; Szymura, Jadwiga; Wiecek, Magdalena; Szygula, Zbigniew; Kepinska, Magdalena; Ochalek, Katarzyna; Pokrywka, Andrzej

    2015-01-01

    The aim of this study was to evaluate the effects of eccentric exercise on anaerobic power, starting speed and anaerobic endurance. The participants performed the maximum cycling sprint test (MCST) prior to eccentric exercise (ECC), 10 minutes after, as well as one hour, 24 hours, 48 hours, and one week after ECC. The peak and mean power, time to attain peak power, time of maintaining peak power and power decrease were measured in the MCST. Before and after ECC, the myoglobin concentration...

  5. Studies on upflow anaerobic filter

    Science.gov (United States)

    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

  6. Anaerobic digestion in sustainable biomass chains

    NARCIS (Netherlands)

    Pabon Pereira, C.P.

    2009-01-01

    This thesis evaluates the potential contribution of anaerobic digestion (AD) to the sustainability of biomass chains. Results provide insights in the technological potential to recover energy and valuable by-products from energy crops and residues, and evaluate biomass cascades involving AD technolo

  7. Anaerobic work capacity in elite wheelchair athletes

    NARCIS (Netherlands)

    van der Woude, L H; Bakker, W H; Elkhuizen, J W; Veeger, DirkJan (H. E. J.); Gwinn, T

    1997-01-01

    To study the anaerobic work capacity in wheelchair athletes, 67 elite wheelchair athletes (50 male) were studied in a 30-second sprint test on a computer-controlled wheelchair ergometer during the World Championships and Games for the Disabled in Assen (1990). The experimental set-up (ergometer, pro

  8. Biodegradability of leathers through anaerobic pathway.

    Science.gov (United States)

    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.

  9. Conversion of Methanogenic Substrates in Anaerobic Reactors

    NARCIS (Netherlands)

    Gonzalez-Gil, G.

    2000-01-01

    The EGSB systems represents an attractive option to extend further the use of anaerobic technology for wastewater treatment, particularly with respect to waste streams originating from chemical industries. Frequently chemical waste streams are unbalanced with respect to nutrients and/or micronutrien

  10. Anaerobic effluent disinfection using ozone: Byproducts formation

    NARCIS (Netherlands)

    Silva, G.H.R.; Daniel, L.A.; Bruning, H.; Rulkens, W.H.

    2010-01-01

    This research was aimed at studying oxidation processes, coliform inactivation effectiveness and disinfection byproducts (DBPs) associated with the disinfection of anaerobic sanitary wastewater effluent with ozone applied at doses of 5.0, 8.0 and 10.0mg O(3)L(-1) for contact times of 5, 10 and 15 mi

  11. Sulfate-reducing bacteria in anaerobic bioreactors.

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the occurrenc

  12. Essential metal depletion in an anaerobic reactor

    NARCIS (Netherlands)

    Osuna, M.B.; Iza, J.M.; Zandvoort, M.H.; Lens, P.N.L.

    2003-01-01

    The effect of the absence of trace elements on the conversion of a mixture of volatile fatty acids by a distillery anaerobic granular sludge was investigated. Two UASB reactors were operated under identical operational conditions except for the influent trace metal concentrations, during 140 days. E

  13. The fate of methanol in anaerobic bioreactors.

    NARCIS (Netherlands)

    Florencio, L.

    1994-01-01

    Methanol is an important component of certain industrial wastewaters. In anaerobic environments, methanol can be utilized by methanogens and acetogens. In wastewater treatment plants, the conversion of methanol into methane is preferred because this conversion is responsible for chemical oxygen dema

  14. An anaerobic mitochondrion that produces hydrogen

    NARCIS (Netherlands)

    Boxma, B.; Graaf, de R.M.; Staay, van der G.W.M.; Alen, T.A.; Richard, G.; Gabalon, T.; Hoek, van A.H.A.M.; Moon - van der Staay, S.Y.; Koopman, W.J.H.; Hellemond, van J.J.; Tielens, A.G.M.; Friedrich, T.; Veenhuis, M.; Huynen, M.A.; Hackstein, J.H.P.

    2005-01-01

    Hydrogenosomes are organelles that produce ATP and hydrogen(1), and are found in various unrelated eukaryotes, such as anaerobic flagellates, chytridiomycete fungi and ciliates(2). Although all of these organelles generate hydrogen, the hydrogenosomes from these organisms are structurally and metabo

  15. Essential metal depletion in an anaerobic reactor.

    NARCIS (Netherlands)

    Osuna, M.B.; Iza, J.M.; Zandvoort, M.H.; Lens, P.N.L.

    2003-01-01

    The effect of the absence of trace elements on the conversion of a mixture of volatile fatty acids by a distillery anaerobic granular sludge was investigated. Two UASB reactors were operated under identical operational conditions except for the influent trace metal concentrations, during 140 days. E

  16. Anaerobic microbial LCFA degradation in bioreactors

    NARCIS (Netherlands)

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

    2008-01-01

    This paper reviews recent results obtained on long-chain fatty acids (LCFA) anaerobic degradation. Two LCFA were used as model substrates: oleate, a mono-unsaturated LCFA, and palmitate, a saturated LCFA, both abundant in LCFA-rich wastewaters. 16S rRNA gene analysis of sludge samples submitted to c

  17. Hemicellulases from anaerobic thermophiles. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Science.gov (United States)

    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...

  19. Anaerobic membrane bioreactors: Are membranes really necessary?

    NARCIS (Netherlands)

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  20. Anaerobic Pre-treatment of Strong Sewage

    NARCIS (Netherlands)

    Halalsheh, M.M.

    2002-01-01

    The main objective of this research was to assess the feasibility of applying low cost anaerobic technology for the treatment of relatively high strength sewage of Jordan using two-stage and one-stage UASB reactors operated at ambient temperatures. The wastewater produced in Jordan is characterised

  1. Anaerobic hydrolysis during digestion of complex substrates

    NARCIS (Netherlands)

    Sanders, W.T.M.

    2001-01-01

    Complex waste(water) such as, raw sewage, dairy wastewater, slaughterhouse wastewater, fish processing wastewater, primary sludge and the organic fraction of municipal solid waste have been proven to be degradable under anaerobic conditions. However, during the digestion process the conversion of th

  2. Intraspecific variation in aerobic and anaerobic locomotion

    DEFF Research Database (Denmark)

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

    2015-01-01

    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady...

  3. Anaerobic Digestion in a Flooded Densified Leachbed

    Science.gov (United States)

    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.

  4. Anaerobic degradation of linear alkylbenzene sulfonate.

    Science.gov (United States)

    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.

  5. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H. [Westinghouse Hanford Co., Richland, WA (United States); Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K. [Russian Academy of Sciences (Russian Federation). Inst. of Physical Chemistry

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  6. Low serum alkaline phosphatase activity in Wilson's disease.

    Science.gov (United States)

    Shaver, W A; Bhatt, H; Combes, B

    1986-01-01

    Low values for serum alkaline phosphatase activity were observed early in the course of two patients with Wilson's disease presenting with the combination of severe liver disease and Coombs' negative acute hemolytic anemia. A review of other cases of Wilson's disease revealed that 11 of 12 patients presenting with hemolytic anemia had values for serum alkaline phosphatase less than their respective sex- and age-adjusted mean values; in eight, serum alkaline phosphatase activity was less than the lower value for the normal range of the test. Low values for serum alkaline phosphatase were much less common in Wilson's disease patients with more chronic forms of presentation. Copper added in high concentration to serum in vitro did not have an important effect on serum alkaline phosphatase activity. The mechanism responsible for the decrease in serum alkaline phosphatase activity in patients is uncertain.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Koupaie, E., E-mail: ehssan.hosseini.k@gmail.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Hashemi, S.H., E-mail: h_hashemi@sbu.ac.ir [Environmental Science Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2011-11-15

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

  8. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  9. [Anaerobic co-digestion of corn stalk and vermicompost].

    Science.gov (United States)

    Chen, Guang-yin; Zheng, Zheng; Zou, Xing-xing; Fang, Cai-xia; Luo, Yan

    2010-02-01

    The characteristics of corn stalk digested alone at different total solid (TS) loading rates and co-digestion of various proportions of corn stalk and vermicompost were investigated by batch model at 35 degrees C +/- 1 degrees C. The organic loading rates (OLRs) studied were in the range of 1.2%-6.0% TS and increasing proportions of vermicompost from 20% to 80% TS. A maximum methane yield of corn stalk digested alone was 217.60 mL/g obtained at the TS loading rate of 4.8%. However, when the TS loading rate was 6.0%, the anaerobic system was acidified and the lowest pH value was 5.10 obtained on day 4 and the biogas productivity decreased. Furthermore, co-digestion of vermicompost and corn stalk in varying proportions were investigated at constant of 6.0% TS. Co-digestion with vermicompost improved the biodegradability of corn stalk and the methane yield was improved by 4.42%-58.61%, and led to higher pH values, higher volatile fatty acids (VFAs) concentration and lower alkalinity content compared with corn stalk digested alone. The maximum biogas yield and methane yield of 410.30 mL/g and 259. 35 mL/g were obtained for 40% vermicompost and 60% corn stalk respectively. Compared with corn stalk digested alone, co-digested with vermicompost didn' t affect methane content and the fermentation type, but promoted the destruction of crystalline of cellulose and the highest destruction rate was 29.36% for 40% vermicompost and 60% corn stalk. Therefore, adding vermicompost was beneficial for the decomposition and increasing the biotransformation rate of corn stalk.

  10. Variations of the Respiration Signals for Respiratory-Gated Radiotherapy Using the Video Coached Respiration Guiding System

    CERN Document Server

    Lee, Hyun Jeong; Oh, Se An

    2015-01-01

    Respiratory-gated radiation therapy (RGRT) has been used to minimize the dose to normal tissue in lung-cancer radiotherapy. The present research aims to improve the regularity of respiration in RGRT using a video coached respiration guiding system. In the study, 16 patients with lung cancer were evaluated. The respiration signals of the patients were measured by a real-time position management (RPM) Respiratory Gating System (Varian, USA) and the patients were trained using the video coached respiration guiding system. The patients performed free breathing and guided breathing, and the respiratory cycles were acquired for ~5 min. Then, Microsoft Excel 2010 software was used to calculate the mean and standard deviation for each phase. The standard deviation was computed in order to analyze the improvement in the respiratory regularity with respect to the period and displacement. The standard deviation of the guided breathing decreased to 65.14% in the inhale peak and 71.04% in the exhale peak compared with the...

  11. The effect of alkaline agents on retention of EOR chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, P.B.

    1991-07-01

    This report summarizes a literature survey on how alkaline agents reduce losses of surfactants and polymers in oil recovery by chemical injection. Data are reviewed for crude sulfonates, clean anionic surfactants, nonionic surfactants, and anionic and nonionic polymers. The role of mineral chemistry is briefly described. Specific effects of various alkaline anions are discussed. Investigations needed to improve the design of alkaline-surfactant-polymer floods are suggested. 62 refs., 28 figs., 6 tabs.

  12. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

    DEFF Research Database (Denmark)

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

    2015-01-01

    Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrifica...

  13. Anaerobic benzene oxidation by Geobacter species.

    Science.gov (United States)

    Zhang, Tian; Bain, Timothy S; Nevin, Kelly P; Barlett, Melissa A; Lovley, Derek R

    2012-12-01

    The abundance of Geobacter species in contaminated aquifers in which benzene is anaerobically degraded has led to the suggestion that some Geobacter species might be capable of anaerobic benzene degradation, but this has never been documented. A strain of Geobacter, designated strain Ben, was isolated from sediments from the Fe(III)-reducing zone of a petroleum-contaminated aquifer in which there was significant capacity for anaerobic benzene oxidation. Strain Ben grew in a medium with benzene as the sole electron donor and Fe(III) oxide as the sole electron acceptor. Furthermore, additional evaluation of Geobacter metallireducens demonstrated that it could also grow in benzene-Fe(III) medium. In both strain Ben and G. metallireducens the stoichiometry of benzene metabolism and Fe(III) reduction was consistent with the oxidation of benzene to carbon dioxide with Fe(III) serving as the sole electron acceptor. With benzene as the electron donor, and Fe(III) oxide (strain Ben) or Fe(III) citrate (G. metallireducens) as the electron acceptor, the cell yields of strain Ben and G. metallireducens were 3.2 × 10(9) and 8.4 × 10(9) cells/mmol of Fe(III) reduced, respectively. Strain Ben also oxidized benzene with anthraquinone-2,6-disulfonate (AQDS) as the sole electron acceptor with cell yields of 5.9 × 10(9) cells/mmol of AQDS reduced. Strain Ben serves as model organism for the study of anaerobic benzene metabolism in petroleum-contaminated aquifers, and G. metallireducens is the first anaerobic benzene-degrading organism that can be genetically manipulated.

  14. Winery and distillery wastewater treatment by anaerobic digestion.

    Science.gov (United States)

    Moletta, R

    2005-01-01

    Anaerobic digestion is widely used for wastewater treatment, especially in the food industries. Generally after the anaerobic treatment there is an aerobic post-treatment in order to return the treated water to nature. Several technologies are applied for winery wastewater treatment. They are using free cells or flocs (anaerobic contact digesters, anaerobic sequencing batch reactors and anaerobic lagoons), anaerobic granules (Upflow Anaerobic Sludge Blanket--UASB), or biofilms on fixed support (anaerobic filter) or on mobile support as with the fluidised bed. Some technologies include two strategies, e.g. a sludge bed with anaerobic filter as in the hybrid digester. With winery wastewaters (as for vinasses from distilleries) the removal yield for anaerobic digestion is very high, up to 90-95% COD removal. The organic loads are between 5 and 15 kgCOD/m3 of digester/day. The biogas production is between 400 and 600 L per kg COD removed with 60 to 70% methane content. For anaerobic and aerobic post-treatment of vinasses in the Cognac region, REVICO company has 99.7% COD removal and the cost is 0.52 Euro/m3 of vinasses.

  15. 30 CFR 71.101 - Respirable dust standard when quartz is present.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust standard when quartz is present... UNDERGROUND COAL MINES Dust Standards § 71.101 Respirable dust standard when quartz is present. When the respirable dust in the mine atmosphere of the active workings contains more than 5 percent quartz,...

  16. 30 CFR 70.101 - Respirable dust standard when quartz is present.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust standard when quartz is present... Respirable dust standard when quartz is present. When the respirable dust in the mine atmosphere of the active workings contains more than 5 percent quartz, the operator shall continuously maintain the...

  17. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Isoamyl acetate tightness test; respirators... Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1142 Isoamyl acetate tightness test; respirators designed for respiratory protection...

  18. 76 FR 28811 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Respirator...

    Science.gov (United States)

    2011-05-18

    ...; Respirator Program Records ACTION: Notice. SUMMARY: The Department of Labor (DOL) is submitting the Mine..., ``Respirator Program Records,'' to the Office of Management and Budget (OMB) for review and approval for... equipment is used, metal and nonmetal mine operators institute a respirator program governing...

  19. 42 CFR 84.36 - Delivery of changed or modified approved respirator.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Delivery of changed or modified approved respirator... Approval and Disapproval § 84.36 Delivery of changed or modified approved respirator. An approved respirator for which a formal certificate of modification has been issued shall be delivered, with...

  20. 42 CFR 84.1102 - Examination, inspection and testing of complete respirator assemblies; fees.

    Science.gov (United States)

    2010-10-01

    ... respirator assemblies; fees. 84.1102 Section 84.1102 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1102 Examination, inspection and testing of complete respirator assemblies; fees. The following fees shall be charged by the Institute for the...

  1. 42 CFR 84.171 - Non-powered air-purifying particulate respirators; required components.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... PROTECTIVE DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.171 Non-powered air-purifying particulate respirators; required components. (a) Each non-powered air-purifying particulate...

  2. 42 CFR 84.3 - Respirators for mine rescue or other emergency use in mines.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirators for mine rescue or other emergency use... DEVICES General Provisions § 84.3 Respirators for mine rescue or other emergency use in mines. (a)(1... review and issue certifications for respirators used for mine emergencies and mine rescue, including...

  3. 42 CFR 84.12 - Delivery of respirators and components by applicant; requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Delivery of respirators and components by applicant... Application for Approval § 84.12 Delivery of respirators and components by applicant; requirements. (a) Each... number of respirators and component parts required for testing. (b) The applicant shall deliver, at...

  4. 42 CFR 84.20 - Examination, inspection, and testing of complete respirator assemblies; fees.

    Science.gov (United States)

    2010-10-01

    ... respirator assemblies; fees. 84.20 Section 84.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... RESPIRATORY PROTECTIVE DEVICES Fees § 84.20 Examination, inspection, and testing of complete respirator... examination, inspection and testing of complete respirator assemblies: Self-contained breathing...

  5. 30 CFR 72.710 - Selection, fit, use, and maintenance of approved respirators.

    Science.gov (United States)

    2010-07-01

    ... approved respirators. 72.710 Section 72.710 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Selection, fit, use, and maintenance of approved respirators. In order to ensure the maximum amount of respiratory protection, approved respirators shall be selected, fitted, used, and maintained in...

  6. 10 CFR Appendix A to Part 20 - Assigned Protection Factors for Respirators a

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Assigned Protection Factors for Respirators a A Appendix A..., App. A Appendix A to Part 20—Assigned Protection Factors for Respirators a Operating mode AssignedProtection Factors I. Air Purifying Respirators c: Filtering facepiece disposable d Negative Pressure...

  7. [Effects of nitrogen fertilization on soil respiration during maize growth season].

    Science.gov (United States)

    Li, Jian-Min; Ding, Wei-Xin; Cai, Zu-Cong

    2010-08-01

    In order to understand how nitrogen (N) fertilization affects soil respiration, a pot experiment with splitting-root compartment and by root-cutting was conducted in a greenhouse. The experiment had four treatments, i. e., unplanted and N-unfertilized (CKO), unplanted but fertilized with 150 mg N x kg(-1) CKN), planted maize (Zea mays L.) but N-unfertilized (MO), and planted maize and fertilized with 150 mg N x kg(-1) (MN). Soil respiration, soil basal respiration, root respiration, and rhizospheric microbial respiration were measured simultaneously. In unplanted soils (treatments CKO and CKN), soil respiration rate (soil basal respiration) ranged from 13.41 to 77.27 mg C x m(-2) x h(-1), and N fertilization had less effect; while in planted soils, the averaged soil respiration rate in treatment MN amounted to 138.54 mg C x m(-2) x h(-1), and was 17.7% higher (P < 0.05) than that in treatment MO. This increment mainly occurred at tasselling and flowering stages. During maize growth season, the contribution of soil basal respiration, root respiration, and rhizospheric microbial respiration to soil respiration in treatments MN and MO was 36.2%, 45.9%, and 17.9%, and 35.5%, 36.9%, and 37.6%, respectively.

  8. Respirator studies for the National Institute for Occupational Safety and Health. Progress report, July 1, 1974--June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, D.D.; Revoir, W.; Lowry, P.L.

    1976-08-01

    Respirator studies carried out in FY 1975 for the National Institute for Occupational Safety and Health were concentrated in two major areas: (1) the development of respirator test equipment and methods to improve the means of evaluating the performance of respirators, (2) the testing of respirators to obtain quantitative data to permit recommendations to be made to upgrade respirator performance criteria. Major accomplishments included obtaining man-test results on several different respirators using an anthropometrically selected test panel, determination of respirator exhalation valve leakages under static and dynamic conditions, and determination of the effects of respirator strap tension on facepiece leakage.

  9. Anaerobic protozoa and their growth in biomethanation systems.

    Science.gov (United States)

    Priya, M; Haridas, Ajit; Manilal, V B

    2008-04-01

    This study was to investigate growth of protozoa and its influence on biodegradation in anaerobic treatment systems. It was done by specifically controlling and monitoring growth of protozoa versus degradation in continuous stirred anaerobic reactors and batch anaerobic reactors. Occurrence of a diverse protozoa population such as the ciliates, Prorodon, Vorticella, Cyclidium, Spathidium, Loxodes, Metopus were observed in stable anaerobic systems and the flagellates, Rhynchomonas, Naeglaria, Amoeboflagellates, Tetramitus, Trepomonas and Bodo during increased VFA concentration and affected periods of biomethanation. The abundance of ciliates in the anaerobic system had significant correlation with the reduction of MLSS, increased rate of COD removal and higher methane production. The results of this study thus tend to relate increased anaerobic degradation with the abundance of protozoa, mainly ciliates, which indicate their possible involvement in the process. Present study also reveals that performance of anaerobic process can be assessed by monitoring the protozoa population in the system.

  10. Removal of organics and nutrients from food wastewater using combined thermophilic two-phase anaerobic digestion and shortcut biological nitrogen removal.

    Science.gov (United States)

    Cui, Fenghao; Lee, Seungho; Kim, Moonil

    2011-10-15

    A process combining pilot-scale two-phase anaerobic digestion and shortcut biological nitrogen removal (SBNR) was developed to treat organics and nutrients (nitrogen and phosphorus) from food wastewater. The thermophilic two-phase anaerobic digestion process was investigated without adjusting the pH of the wastewater for the pre-acidification process. The digested food wastewater was treated using the SBNR process without supplemental carbon sources or alkalinity. Under these circumstances, the combined system was able to remove about 99% of COD, 88% of TN, and 97% of TP. However, considerable amounts of nutrients were removed due to chemical precipitation processes between the anaerobic digestion and SBNR. The average TN removal efficiency of the SBNR process was about 74% at very low C/N (TCOD/TN) ratio of 2. The SBNR process removed about 39% of TP from the digested food wastewater. Conclusively, application of the combined system improved organic removal efficiency while producing valuable energy (biogas), removed nitrogen at a low C/N ratio, and conserved additional resources (carbon and alkalinity).

  11. Comparative evaluation of anaerobic digestion for sewage sludge and various organic wastes with simple modeling.

    Science.gov (United States)

    Hidaka, Taira; Wang, Feng; Tsumori, Jun

    2015-09-01

    Anaerobic co-digestion of sewage sludge and other organic wastes, such as kitchen garbage, food waste, and agricultural waste, at a wastewater treatment plant (WWTP) is a promising method for both energy and material recovery. Substrate characteristics and the anaerobic digestion performance of sewage sludge and various organic wastes were compared using experiments and modeling. Co-digestion improved the value of digested sewage sludge as a fertilizer. The relationship between total and soluble elemental concentrations was correlated with the periodic table: most Na and K (alkali metals) were soluble, and around 20-40% of Mg and around 10-20% of Ca (alkaline earth metals) were soluble. The ratio of biodegradable chemical oxygen demand of organic wastes was 65-90%. The methane conversion ratio and methane production rate under mesophilic conditions were evaluated using a simplified mathematical model. There was reasonably close agreement between the model simulations and the experimental results in terms of methane production and nitrogen concentration. These results provide valuable information and indicate that the model can be used as a pre-evaluation tool to facilitate the introduction of co-digestion at WWTPs.

  12. Anaerobic digestion of food waste stabilized by lime mud from papermaking process.

    Science.gov (United States)

    Zhang, Jishi; Wang, Qinqing; Zheng, Pengwei; Wang, Yusong

    2014-10-01

    The effects of lime mud from papermaking process (LMP) addition as buffer agent and inorganic nutrient on the anaerobic digestion stability of food waste (FW) were investigated under mesophilic conditions with the aim of avoiding volatile fatty acids accumulation, and inorganic elements deficiency. When LMP concentration ranged from 6.0 to 10g/L, the FW anaerobic digestion could maintain efficient and stable state. These advantages are attributed to the existence of Ca, Na, Mg, K, Fe, and alkaline substances that favor the methanogenic process. The highest CH4 yield of 272.8mL/g-VS was obtained at LMP and VS concentrations of 10.0 and 19.8g/L, respectively, with the corresponding lag-phase time of 3.84d and final pH of 8.4. The methanogens from residue digestates mainly consisted of Methanobrevibacter, coccus-type and sarcina-type methanogens with LMP addition compared to Methanobacteria in control. However, higher concentration of LMP inhibited methanogenic activities and methane production.

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

    Directory of Open Access Journals (Sweden)

    Lalbiaktluangi

    2015-12-01

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

  14. Estimating heterotrophic respiration at large scales: challenges, approaches, and next steps

    Energy Technology Data Exchange (ETDEWEB)

    Bond-Lamberty, Benjamin; Epron, Daniel; Harden, Jennifer W.; Harmon, Mark; Hoffman, F. M.; Kumar, Jitendra; McGuire, A. David; Vargas, Rodrigo

    2016-06-27

    Heterotrophic respiration (HR), the aerobic and anaerobic processes mineralizing organic matter, is a key carbon flux but one impossible to measure at scales significantly larger than small experimental plots. This impedes our ability to understand carbon and nutrient cycles, benchmark models, or reliably upscale point measurements. Given that a new generation of highly mechanistic, genomic-specific global models is not imminent, we suggest that a useful step to improve this situation would be the development of "Decomposition Functional Types" (DFTs). Analogous to plant functional types (PFTs), DFTs would abstract and capture important differences in HR metabolism and flux dynamics, allowing models to efficiently group and vary these characteristics across space and time. We argue that DFTs should be initially informed by top-down expert opinion, but ultimately developed using bottom-up, data-driven analyses, and provide specific examples of potential dependent and independent variables that could be used. We present and discuss an example clustering analysis to show how model-produced annual HR can be broken into distinct groups associated with global variability in biotic and abiotic factors, and demonstrate that these groups are distinct from already-existing PFTs. A similar analysis, incorporating observational data, could form a basis for future DFTs. Finally, we suggest next steps and critical priorities: collection and synthesis of existing data; more in-depth analyses combining open data with high-performance computing; rigorous testing of analytical results; and planning by the global modeling community for decoupling decomposition from fixed site data. These are all critical steps to build a foundation for DFTs in global models, thus providing the ecological and climate change communities with robust, scalable estimates of HR at large scales.

  15. Investigation of Sulfate concentration influence on Anaerobic Lagoon performance: Birjand Wastewater Treatment plant: A Case study

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2016-05-01

    Full Text Available Background and Aim: In the present study the influence of the different sulfate concentration on the anaerobic lagoon stabilization was investigated. Materials and Methods: The present study is an experimental research carried out on anaerobic stabilization pond pilot for 7 months in Birjand wastewater treatment plant. After making sure of a steady state sulfate with different concentrations of 200, 300 and 400 mg/L were injected into the pilot. Then parameters including pH, organic nitrogen, ammonia nitrogen, BOD5, COD and nitrate were measured. All of the experiments were carried out according to the methods presented in the book "Standard Method" for the examination of water and wastewater (2005. Results: It was found that by increasing sulfate concentration from 200 to 300 mg/L all of parameters  except BOD5 (10% reduction had no significant changes., but by increasing the sulfate concentration from 200 to 400 mg/L the removal efficiency of the parameters such as BOD5, COD, Organic nitrogen, total kjeldahl nitrogen, nitrate and sulfate reduced to 11, 8, 12, 26, 6 and 10 percent, respectively. PH in the first stage was alkaline and then changed to acidic. Conclusion: Anaerobic stabilization ponds have different capacities for removal of organic compounds at different sulfate concentrations; so that; in sulfate concentration of 200 mg/L, the proper operation was seen and in concentration of 300 mg/L, sulfate-reducing bacteria get dominant and therefore odor is produced..  Alternatively, by increasing the concentration of sulphate to 400 mg/L, ammonia nitrogen increased 2.5 times (150% in the effluent.

  16. Characterization and treatment of Denizli landfill leachate using anaerobic hybrid/aerobic CSTR systems.

    Science.gov (United States)

    Ağdağ, Osman Nuri

    2011-01-01

    Leachate generated in municipal solid waste landfill contains large amounts of organic and inorganic contaminants. In the scope of the study, characterization and anaerobic/aerobic treatability of leachate from Denizli (Turkey) Sanitary Landfill were investigated. Time-based fluctuations in characteristics of leachate were monitored during a one-year period. In characterization study; chemical oxygen demand (COD), biochemical oxygen demand (BOD) dissolved oxygen, temperature, pH, alkalinity, volatile fatty acids, total nitrogen, NH4-N, BOD5/COD ratio, suspended solid, inert COD, anaerobic toxicity assay and heavy metals concentrations in leachate were monitored. Average COD, BOD and NH4-N concentration in leachate were measured as 18034 mg/l, 11504 mg/l and 454 mg/l, respectively. Generally, pollution parameters in leachate were higher in summer and relatively lower in winter due to dilution by precipitation. For treatment of leachate, two different reactors, namely anaerobic hybrid and aerobic completely stirred tank reactor (CSTR) having effective volumes of 17.7 and 10.5 litres, respectively, were used. After 41 days of start-up period, leachate was loaded to hybrid reactor at 10 different organic loading rates (OLRs). OLR was increased by increasing COD concentrations. COD removal efficiency of hybrid reactor was carried out at a maximum of 91%. A percentage of 96% of residual COD was removed in the aerobic reactor. NH4-N removal rate in CSTR was quite high. In addition, high methane content was obtained as 64% in the hybrid reactor. At the end of the study, after 170 operation days, it can be said that the hybrid reactor and CSTR were very effective for leachate treatment.

  17. Contribution of Root Respiration to Total Soil Respiration in a Betula ermanii-Dark Coniferous Forest Ecotone of the Changbai Mountains, China

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; HAN Shi-Jie; ZHOU Yu-Mei; ZHANG Jun-Hui

    2005-01-01

    Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evaluate the seasonal variations of soil respiration, to assess the effect of soil temperature and water content on soil respiration, and to estimate the relative contributions of root respiration to the total soil respiration. PVC cylinders in each of 5 forest types of a B. ermanii-dark coniferous forest ecotone were used to measure soil respirations both inside and outside of the cylinders. The contribution of roots to the total soil respiration rates ranged from 12.5% to 54.6%. The mean contribution of roots for the different plots varied with the season, increasing from 32.5% on June 26 to 36.6% on August 3 and to 41.8% on October 14.In addition, there existed a significant (P < 0.01) logarithmic relationship between total soil respiration rate and soil temperature at 5 cm soil depth. Also, a similar trend was observed for the soil respiration and soil water content at the surface (0-5 cm) during the same period of time.

  18. Anaerobic digestion of Chinese cabbage waste silage with swine manure for biogas production: batch and continuous study.

    Science.gov (United States)

    Kafle, Gopi Krishna; Bhattarai, Sujala; Kim, Sang Hun; Chen, Lide

    2014-01-01

    The aim of this study was to investigate the potential for anaerobic co-digestion of Chinese cabbage waste silage (CCWS) with swine manure (SM). Batch and continuous experiments were carried out under mesophilic anaerobic conditions (36-38°C). The batch test evaluated the effect of CCWS co-digestion with SM (SM: CCWS=100:0; 25:75; 33:67; 0:100, % volatile solids (VS) basis). The continuous test evaluated the performance of a single stage completely stirred tank reactor with SM alone and with a mixture of SM and CCWS. Batch test results showed no significant difference in biogas yield up to 25-33% of CCWS; however, biogas yield was significantly decreased when CCWS contents in feed increased to 67% and 100%. When testing continuous digestion, the biogas yield at organic loading rate (OLR) of 2.0 g VSL⁻¹ d⁻¹ increased by 17% with a mixture of SM and CCWS (SM:CCWS=75:25) (423 mL g⁻¹ VS) than with SM alone (361 mL g⁻¹ VS). The continuous anaerobic digestion process (biogas production, pH, total volatile fatty acids (TVFA) and TVFA/total alkalinity ratios) was stable when co-digesting SM and CCWS (75:25) at OLR of 2.0 g VSL⁻¹ d⁻¹ and hydraulic retention time of 20 days under mesophilic conditions.

  19. Anaerobic monodigestion of poultry manure: determination of operational parameters for CSTR.

    Science.gov (United States)

    Chamy, R; León, C; Vivanco, E; Poirrier, P; Ramos, C

    2012-01-01

    In this work the anaerobic monodigestion for the treatment of turkey manure was evaluated, without its codigestion with another substrate. The effect of the organic loading rate (OLR) and the substrate concentration (high total solids (TS) concentration) or product concentration (high volatile fatty acids (VFA) and/or ammonia (NH(3)-N) concentrations) was studied. The results show that for a continuous stirred tank reactor (CSTR) operation, a maximum of 40 g/L of TS and 4.0 g/L of ammonium (NH(4)(+)) was required. In addition, the maximum organic loading rate (OLR) will not exceed 1.5 kg VS/m(3)d. Higher TS and NH(4)(+) concentrations and OLR lead to a reduction on the methane productivity and volatile solids (VS) removal. During the CSTR operation, a high alkalinity concentration (above 10 g/L CaCO(3)) was found; this situation allowed maintaining a constant and appropriate pH (close to 7.8), despite the VFA accumulation. In this sense, the alkalinity ratio (α) is a more appropriate control and monitoring parameter of the reactor operation compared to pH. Additionally, with this parameter a VS removal of 80% with a methane productivity of 0.50 m(3)(CH4)/m(3)(R)d is achieved.

  20. Anaerobic digestion of pig and dairy manure under photo-dark fermentation condition.

    Science.gov (United States)

    Yin, Dongxue; Liu, Wei; Zhai, Ningning; Yang, Gaihe; Wang, Xiaojiao; Feng, Yongzhong; Ren, Guangxin

    2014-08-01

    Anaerobic digestion (AD) with livestock manure is a promising way for biogas production. This work presents the influence of photo-dark fermentation on biogas production of pig manure (PM) and dairy manure (DM). All sets were conducted with temperature 35 ± 2 °C and total solid concentrations 8%: PM₁ and DM₁ in transparent reactor under sunlight for photo-dark fermentation, and PM₂ and DM₂ in non-transparent reactor for dark fermentation. DM₂ had the best cumulative biogas production (CBP) of 15,447.5 mL, followed by PM₁ (15,020 mL) with stable pH and low total ammonium nitrogen (TAN) concentration (1384.99 mg/L), and DM₁ and PM₂. The CBP of DM₂ was 5.77 times as much as PM₂. The relationship between CBP and four factors including volatile fatty acid (VFA), TAN, total alkalinity and pH was analyzed. pH gained the maximum determination coefficient with the CBP among all sets and total alkalinity showed negative correlation with CBP of PM₁ and DM₁.

  1. Polyvinyl alcohol membranes as alkaline battery separators

    Science.gov (United States)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  2. Acylglucuronide in alkaline conditions: migration vs. hydrolysis.

    Science.gov (United States)

    Di Meo, Florent; Steel, Michele; Nicolas, Picard; Marquet, Pierre; Duroux, Jean-Luc; Trouillas, Patrick

    2013-06-01

    This work rationalizes the glucuronidation process (one of the reactions of the phase II metabolism) for drugs having a carboxylic acid moiety. At this stage, acylglucuronides (AG) metabolites are produced, that have largely been reported in the literature for various drugs (e.g., mycophenolic acid (MPA), diclofenac, ibuprofen, phenylacetic acids). The competition between migration and hydrolysis is rationalized by adequate quantum calculations, combing MP2 and density functional theory (DFT) methods. At the molecular scale, the former process is a real rotation of the drug around the glucuconic acid. This chemical-engine provides four different metabolites with various toxicities. Migration definitely appears feasible under alkaline conditions, making proton release from the OH groups. The latter reaction (hydrolysis) releases the free drug, so the competition is of crucial importance to tackle drug action and elimination. From the theoretical data, both migration and hydrolysis appear kinetically and thermodynamically favored, respectively.

  3. Hydrogen production by alkaline water electrolysis

    Directory of Open Access Journals (Sweden)

    Diogo M. F. Santos

    2013-01-01

    Full Text Available Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article, the electrochemical fundamentals of alkaline water electrolysis are explained and the main process constraints (e.g., electrical, reaction, and transport are analyzed. The historical background of water electrolysis is described, different technologies are compared, and main research needs for the development of water electrolysis technologies are discussed.

  4. Advanced-capability alkaline fuel cell powerplant

    Science.gov (United States)

    Deronck, Henry J.

    The alkaline fuel cell powerplant utilized in the Space Shuttle Orbiter has established an excellent performance and reliability record over the past decade. Recent AFC technology programs have demonstrated significant advances in cell durability and power density. These capabilities provide the basis for substantial improvement of the Orbiter powerplant, enabling new mission applications as well as enhancing performance in the Orbiter. Improved durability would extend the powerplant's time between overhaul fivefold, and permit longer-duration missions. The powerplant would also be a strong candidate for lunar/planetary surface power systems. Higher power capability would enable replacement of the Orbiter's auxiliary power units with electric motors, and benefits mass-critical applications such as the National AeroSpace Plane.

  5. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    and oxygen with a new type of alkaline electrolysis cell at high temperatures and pressures. To perform measurements under high pressure and at elevated temperatures it was necessary to build a measurement system around an autoclave which could stand high temperatures up to 250 °C and pressures up to 200 bar...... as well as extremely caustic environments. Based on a literature study to identify resistant materials for these conditions, Inconel 600 was selected among the metals which are available for autoclave construction. An initial single atmosphere high temperature and pressure measurement setup was build...... comprising this autoclave. A second high temperature and pressure measurement setup was build based on experiences from the first setup in order to perform automatized measurements. The conductivity of aqueous KOH at elevated temperatures and high concentrations was investigated using the van der Pauw method...

  6. RES Hydrogen: efficient pressurised alkaline electrolysers

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Bentzen, Janet Jonna; Jørgensen, Peter Stanley;

    including BoP. Investigation of cathodes revealed highly heterogeneous microstructures and 3D microstructure quantification methods were developed. Nanometre scale -Ni(OH)2 formation was identified on tested cathode surfaces and is considered a potential degradation mechanism that is not presently well......The RESelyser project addresses issues associated with coupling alkaline electrolysis to renewable energy sources such as electrode stability and gas purity by implementing improved electrodes and a new separator membrane concept. The project aims to improve performance, operation pressure...... and reduce system cost. The project supports DTU Energy's activities on electrodes within the larger FCH-JU project. The overall project demonstrated: improved electrode efficiency also during cyclic operation, safe gas purity at a system pressure of 30 bar, 10 kW stack operation and estimated system costs...

  7. Enzymatic Hydrolysis of Alkaline Pretreated Coconut Coir

    Directory of Open Access Journals (Sweden)

    Akbarningrum Fatmawati

    2013-06-01

    Full Text Available The purpose of this research is to study the effect of concentration and temperature on the cellulose and lignin content, and the reducing sugars produced in the enzymatic hydrolysis of coconut coir. In this research, the coconut coir is pretreated using 3%, 7%, and 11% NaOH solution at 60oC, 80oC, and 100oC. The pretreated coir were assayed by measuring the amount of cellulose and lignin and then hydrolysed using Celluclast and Novozyme 188 under various temperature (30oC, 40oC, 50oC and pH (3, 4, 5. The hydrolysis results were assayed for the reducing sugar content. The results showed that the alkaline delignification was effective to reduce lignin and to increase the cellulose content of the coir. The best delignification condition was observed at 11% NaOH solution and 100oC which removed 14,53% of lignin and increased the cellulose content up to 50,23%. The best condition of the enzymatic hydrolysis was obtained at 50oC and pH 4 which produced 7,57 gr/L reducing sugar. © 2013 BCREC UNDIP. All rights reservedReceived: 2nd October 2012; Revised: 31st January 2013; Accepted: 6th February 2013[How to Cite: Fatmawati, A., Agustriyanto, R., Liasari, Y. (2013. Enzymatic Hydrolysis of Alkaline Pre-treated Coconut Coir. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 34-39 (doi:10.9767/bcrec.8.1.4048.34-39[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4048.34-39] | View in  |

  8. On electrochemical devices using alkaline polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, L. [Wuhan Univ., Wuhan (China). Dept. of Chemistry

    2010-07-01

    Solid polymer electrolytes (SPEs) enable a compact assembly of fuel cells and electrolyzers, thereby increasing the space-specific conversion efficiency and avoiding electrolyte leakage. The most widely used SPE in proton exchange membrane fuel cells (PEMFC) and chloro-alkali electrolyzers is Nafion. However, this strongly acidic polyelectrolyte allows only noble metals to be used as the catalysts in the electrochemical devices, which poses a problem in terms of price and resource limits. In principle, alkaline polymer electrolytes (APEs) should be used to eliminate the dependence on noble metal catalysts. The general structure of alkaline polymer electrolytes is a positively charged polymer, notably, a polymer chain attached with fixed cations such as quaternary ammonia group, and dissociated anion, OH-, to act as the charge carrier. This presentation described the challenges of developing APEs in terms of the chemical stability of quaternary ammonia group, the mobility of OH-, and high ionic concentration. The authors have been working on developing high-performance APEs since 2001. The most recent APEs were quaternary ammonia polysulfone (QAPS), which were found to be suitable for fuel cell and electrolyzer applications. The ionic conductivity was high and the crosslinked membrane had excellent mechanical strength, enabling operation at 90 degrees C. Non-precious metal catalysts were used in the APEs. For APE-based fuel cells (APEFC), chromium decorated nickel was used as the anode catalyst for hydrogen oxidation, and silver was used as the cathode catalyst for oxygen reduction. The preliminary performance of such an APEFC with non-Pt catalysts was found to be much better than that of traditional water electrolyzers using KOH solutions. 2 refs.

  9. Respirable crystalline silica - a failure to control exposureexclamation

    Energy Technology Data Exchange (ETDEWEB)

    Cain, J R, E-mail: john.cain@hse.gsi.gov.u [HM Regional Specialist Inspector (Occupational Hygiene), Health and Safety Executive, Marshalls Mill, Marshall Street, Leeds LS11 9YJ (United Kingdom)

    2009-02-01

    Several sites were visited to monitor stonemason exposure to respirable crystalline silica (RCS), inhalable dust and respirable dust. At all sites, exposure to RCS exceeded the Workplace Exposure Limit of 0.1 mg/m{sup 3} 8-hour TWA. There was therefore a continuing high risk of workers developing silicosis unless the appropriate measures were instigated to prevent or control exposure. Exposure control was ineffective at all sites e.g. water wall extraction systems were not well designed. There was evidence that foreign workers were at a greater exposure risk. But even with appropriate controls to mitigate exposure to RCS it may not be possible to sustain exposure to below 0.1 mg/m{sup 3} 8-hour TWA without on-going HSE intervention.

  10. Virulence factors enhance Citrobacter rodentium expansion through aerobic respiration.

    Science.gov (United States)

    Lopez, Christopher A; Miller, Brittany M; Rivera-Chávez, Fabian; Velazquez, Eric M; Byndloss, Mariana X; Chávez-Arroyo, Alfredo; Lokken, Kristen L; Tsolis, Renée M; Winter, Sebastian E; Bäumler, Andreas J

    2016-09-16

    Citrobacter rodentium uses a type III secretion system (T3SS) to induce colonic crypt hyperplasia in mice, thereby gaining an edge during its competition with the gut microbiota through an unknown mechanism. Here, we show that by triggering colonic crypt hyperplasia, the C. rodentium T3SS induced an excessive expansion of undifferentiated Ki67-positive epithelial cells, which increased oxygenation of the mucosal surface and drove an aerobic C. rodentium expansion in the colon. Treatment of mice with the γ-secretase inhibitor dibenzazepine to diminish Notch-driven colonic crypt hyperplasia curtailed the fitness advantage conferred by aerobic respiration during C. rodentium infection. We conclude that C. rodentium uses its T3SS to induce histopathological lesions that generate an intestinal microenvironment in which growth of the pathogen is fueled by aerobic respiration.

  11. Nursing diagnoses identified in children with acute respiration infection

    Directory of Open Access Journals (Sweden)

    Flávia Paula Magalhães Monteiro

    2006-08-01

    Full Text Available A cross-sectional study developed with 78 children with until five years old, bearers of acute respiration infection interned in pediatric hospital of the periphery of a great city, with the purpose to identify the nursing diagnoses presented by these children. The number of nursing diagnoses, defining characteristics, related factors and risk factors identified and other numerical variables were analyzed based in theirs central tendency and dispersion measures. It was identified a total of 26 nursing diagnoses, 43 related factors, 14 risk factors e 67 defining characteristics. In average, It was found 5,32 nursing diagnoses; 4,10 related factors; 2,03 risk factors and 7,33 defining characteristics. The nursing diagnoses with the biggest proportion were: Ineffective Breathing Pattern, Risk for delayed growth, Ineffective protection and Altered oral mucous membrane. We concluded that children with acute respiration infection present a complex diagnostic frame including human responses of multiples domains.

  12. Measuring priming using 14C of respired CO2: effects on respiration source pools and interactions with warming

    Science.gov (United States)

    Hopkins, F. M.; Trumbore, S.

    2011-12-01

    The role of substrate availability on soil carbon turnover is a critical unknown in predicting future soil carbon stocks. Substrate composition and availability can be altered by land cover change, warming, and nitrogen deposition, which can in turn affect soil carbon stocks through the priming effect. In particular, little is understood about the interaction between warming and changing substrate concentration. We examined the interactions between global change factors and the priming effect using sucrose addition to incubations of soils from two forest Free Air CO2 Enrichment (FACE) sites (Duke and Aspen). In addition to the in situ global change manipulations conducted at these sites, the CO2 fertilization procedure over the decade-long experiment labeled soil carbon pools with fossil-derived carbon (depleted in 14C relative to the background isotope content of soil carbon), allowing us to determine the effect of priming on respiration of soil carbon substrates of different ages. Thus, we used the carbon-13 signature of sucrose-derived CO2 to account for losses of substrate C, and the carbon-14 signature to partition fluxes of soil-derived CO2 between pre-FACE (> 10 y) and FACE derived (positive priming effect-an increase in the rate of soil carbon derived respiration due to sucrose addition. However, the effect of substrate addition on respiratory source pools, as measured by 14C of respiration, varied greatly. At Duke FACE, we observed an increase in 14C content of CO2 of primed soil carbon, whereas at Aspen, we observed no difference. The amount of CO2 released by priming increased with temperature, but was proportionally similar to the amount of increase in basal respiration rates (no differences in Q10). At Duke, both warming and priming served to increase the 14C of respiration, whereas only warming changed 14C of respiration at Aspen. Despite similar overall carbon stocks, differences in the source of the priming effect between the two sites may be due to

  13. Effects of the M40 Respirator on Pulmonary Function Measurements

    Science.gov (United States)

    1990-05-01

    into a Med-Science Model 3000 Pulmonizer . Each set of measurements made on each volunteer was randomized for the four test conditions. 2.2 Test...was screened for any respiratory problem before being accepted for testing. All testing was performed on a Med-Science Model 3000 Pulmonizer . The...Personal Corputer. The Pulmonizer is a standard diagnostic machine used in hospitals for pulmonary function testing. The M40 respirator was interfaced with

  14. [External respiration parameters in workers engaged in synthetic detergents production].

    Science.gov (United States)

    Makhon'ko, M N; Trubetskov, A D

    2005-01-01

    The study covers results of thorough clinical and functional examination of workers engaged into contemporary chemical production. The authors studied effects caused in immunity parameters, respiratory organs and skin by sensitizing and irritating chemicals. Findings are that the most significant changes in external respiration parameters and high predisposition to respiratory diseases are associated with specific sensitizing to industrial allergen and with higher IgE levels.

  15. Ocean acidification decreases plankton respiration: evidence from a mesocosm experiment

    Science.gov (United States)

    Spilling, Kristian; Paul, Allanah J.; Virkkala, Niklas; Hastings, Tom; Lischka, Silke; Stuhr, Annegret; Bermúdez, Rafael; Czerny, Jan; Boxhammer, Tim; Schulz, Kai G.; Ludwig, Andrea; Riebesell, Ulf

    2016-08-01

    Anthropogenic carbon dioxide (CO2) emissions are reducing the pH in the world's oceans. The plankton community is a key component driving biogeochemical fluxes, and the effect of increased CO2 on plankton is critical for understanding the ramifications of ocean acidification on global carbon fluxes. We determined the plankton community composition and measured primary production, respiration rates and carbon export (defined here as carbon sinking out of a shallow, coastal area) during an ocean acidification experiment. Mesocosms ( ˜ 55 m3) were set up in the Baltic Sea with a gradient of CO2 levels initially ranging from ambient ( ˜ 240 µatm), used as control, to high CO2 (up to ˜ 1330 µatm). The phytoplankton community was dominated by dinoflagellates, diatoms, cyanobacteria and chlorophytes, and the zooplankton community by protozoans, heterotrophic dinoflagellates and cladocerans. The plankton community composition was relatively homogenous between treatments. Community respiration rates were lower at high CO2 levels. The carbon-normalized respiration was approximately 40 % lower in the high-CO2 environment compared with the controls during the latter phase of the experiment. We did not, however, detect any effect of increased CO2 on primary production. This could be due to measurement uncertainty, as the measured total particular carbon (TPC) and combined results presented in this special issue suggest that the reduced respiration rate translated into higher net carbon fixation. The percent carbon derived from microscopy counts (both phyto- and zooplankton), of the measured total particular carbon (TPC), decreased from ˜ 26 % at t0 to ˜ 8 % at t31, probably driven by a shift towards smaller plankton (export, and consequently did not work as a negative feedback mechanism for increasing atmospheric CO2 concentration.

  16. The effect of age on mitochondrial enzymes and respiration.

    Science.gov (United States)

    Wilson, P D; Hill, B T; Franks, L M

    1975-01-01

    There was no significant difference between the levels of cytochrome oxidase and malate dehydrogenase in whole liver homogenates or in mitochondria isolated from the livers of 6-month-old and 30-month-old C57/BL mice. Little change with age was found in the cytochemical localisation of either enzyme. There were no significant changes in endogenous, state III or state IV respiration of mitochondria isolated from the livers of young and old mice.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Lisa eGieg

    2013-06-01

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

  19. Facial anthropometric dimensions of Koreans and their associations with fit of quarter-mask respirators.

    Science.gov (United States)

    Kim, Hyunwook; Han, Don-Hee; Roh, Young-Man; Kim, Kangyoon; Park, Yong-Gyu

    2003-01-01

    Past studies on respirator fit or performance have mostly been done for Whites or male subjects, and little attention has been paid to minorities and Asians. To fill this gap, this study was designed to provide facial anthropometric data for Koreans and to analyze the association between facial dimensions and respirator fit factors for three brands of quarter-mask respirators, two domestic and one imported brand, using a Portacount 8020. A total of 110 university student subjects, 70 males and 40 females volunteered for participation in the study. The results of this study showed that Korean males and females have different facial dimensions as compared with those of White males and females. Unexpectedly, the imported respirator performed better than the domestic respirators. Males were found to achieve better respirator fit than females regardless of respirator brands tested. The regression analysis found no common prognostic variables with the three respirator brands studied. A stepwise logistic regression analysis was conducted to find predictive facial dimensions with respirator fits. Some facial dimensions were found to be statistically significant, but these dimensions are different from the traditionally recommended facial dimensions of face length and lip width for quarter mask. To improve respirator fit for Koreans, these different facial characteristics need to be considered in the design of quarter mask respirators.

  20. Effects of bioirrigation of non-biting midges (Diptera: Chironomidae) on lake sediment respiration

    Science.gov (United States)

    Baranov, Viktor; Lewandowski, Jörg; Romeijn, Paul; Singer, Gabriel; Krause, Stefan

    2016-06-01

    Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration. This paper describes a novel method based on the bioreactive tracer resazurin for measuring respiration in-situ in non-sealed systems with constant oxygen supply. Applying this new method in microcosm experiments revealed that bioirrigation enhanced sediment respiration by up to 2.5 times. The new method is yielding lower oxygen consumption than previously reported, as it is only sensitive to aerobic heterotrophous respiration and not to other processes causing oxygen decrease. Hence it decouples the quantification of respiration of animals and inorganic oxygen consumption from microbe respiration in sediment.

  1. Increased river alkalinization in the Eastern U.S

    Science.gov (United States)

    Kaushal, S.; Likens, G. E.; Utz, R.; Pace, M.; Grese, M.; Yepsen, M.

    2013-12-01

    The interaction between human activities and watershed geology is accelerating long-term changes in the carbon cycle of rivers. We evaluated changes in bicarbonate alkalinity, a product of chemical weathering, and tested for long-term trends at 97 sites in the eastern United States draining over 260,000 km2. We observed statistically significant increasing trends in alkalinity at 62 of the 97 sites, while remaining sites exhibited no significant decreasing trends. Over 50% of study sites also had statistically significant increasing trends in concentrations of calcium (another product of chemical weathering) where data were available. River alkalinization rates were significantly related to watershed carbonate lithology, acid deposition, and topography. These 3 variables explained ~40% of variation in river alkalinization rates. The strongest predictor of river alkalinization rates was carbonate lithology. The most rapid rates of river alkalinization occurred at sites with highest inputs of acid deposition and highest elevation. The rise of alkalinity in many rivers throughout the eastern U.S. suggests human-accelerated chemical weathering, in addition to previously documented impacts of mining and land use. Increased river alkalinization has major environmental implications including impacts on water hardness and salinization of drinking water, alterations of air-water exchange of CO2, coastal ocean acidification, and the influence of bicarbonate availability on primary production.

  2. Space-time variability of alkalinity in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. Cossarini

    2014-09-01

    Full Text Available The paper provides a basin assessment of the spatial distribution of ocean alkalinity in the Mediterranean Sea. The assessment is made using a 3-D transport-biogeochemical-carbonate model to integrate the available experimental findings, which also constrains model output. The results indicate that the Mediterranean Sea shows alkalinity values that are much higher than those observed in the Atlantic Ocean on a basin-wide scale. A marked west-to-east surface gradient of alkalinity is reproduced as a response to the terrestrial discharges, the mixing effect with the Atlantic water entering from the Gibraltar Strait and the Black Sea water from Dardanelles, and the surface flux of evaporation minus precipitation. Dense water production in marginal seas (Adriatic and Aegean Seas, where alkaline inputs are relevant, and the Mediterranean thermohaline circulation sustains the west-to-east gradient along the entire water column. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 μmol kg−1 that is driven both by physical and biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships. In regions of freshwater influence, the two measures are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open seas. Alkalinity always is much higher than in the Atlantic waters, which might indicate a higher than usual buffering capacity towards ocean acidification, even at high concentrations of dissolved inorganic carbon.

  3. Increased river alkalinization in the Eastern U.S.

    Science.gov (United States)

    Kaushal, Sujay S; Likens, Gene E; Utz, Ryan M; Pace, Michael L; Grese, Melissa; Yepsen, Metthea

    2013-09-17

    The interaction between human activities and watershed geology is accelerating long-term changes in the carbon cycle of rivers. We evaluated changes in bicarbonate alkalinity, a product of chemical weathering, and tested for long-term trends at 97 sites in the eastern United States draining over 260,000 km(2). We observed statistically significant increasing trends in alkalinity at 62 of the 97 sites, while remaining sites exhibited no significant decreasing trends. Over 50% of study sites also had statistically significant increasing trends in concentrations of calcium (another product of chemical weathering) where data were available. River alkalinization rates were significantly related to watershed carbonate lithology, acid deposition, and topography. These three variables explained ~40% of variation in river alkalinization rates. The strongest predictor of river alkalinization rates was carbonate lithology. The most rapid rates of river alkalinization occurred at sites with highest inputs of acid deposition and highest elevation. The rise of alkalinity in many rivers throughout the Eastern U.S. suggests human-accelerated chemical weathering, in addition to previously documented impacts of mining and land use. Increased river alkalinization has major environmental implications including impacts on water hardness and salinization of drinking water, alterations of air-water exchange of CO2, coastal ocean acidification, and the influence of bicarbonate availability on primary production.

  4. A New Compendium of Soil Respiration Data for Africa

    Directory of Open Access Journals (Sweden)

    Terence Epule Epule

    2015-04-01

    Full Text Available The objective of this paper is to present to the scientific community a new dataset derived from existing literature on soil respiration in Africa. The data has thus been obtained by searching for records in peer review papers and grey literature. The main search engines used are: Scientific Citation Index (SCI database, ISI Science web and Google scholar. This data description paper has greatly advanced the number of data points on soil respiration in Africa from 4 in 2010 to 62 in 2014. The new data points are culled from 47 peer review publications and grey literature reports. The data lends its self to a lot of possible analytical methods such as correlation analysis, multiple linear regressions, artificial neural network analysis and process base modeling. The overall conclusion that can be drawn here is that this paper has greatly advanced the availability of soil respiration data in Africa by presenting all the available records that before now were only reported in different studies.

  5. Ecosystem respiration depends strongly on photosynthesis in a temperate heath

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Ibrom, Andreas; Beier, Claus

    2007-01-01

    ) of 2.5 by the modified model. The model introduces R-photo, which describes the part of respiration being tightly coupled to the photosynthetic rate. It makes up 5% of the assimilated carbon dioxide flux at 0 degrees C and 35% at 20 degrees C implying a high sensitivity of respiration to photosynthesis......We measured net ecosystem CO2 flux (F-n) and ecosystem respiration (R-E), and estimated gross ecosystem photosynthesis (P-g) by difference, for two years in a temperate heath ecosystem using a chamber method. The exchange rates of carbon were high and of similar magnitude as for productive forest.......65) was improved when the P-g rate was incorporated into the model (second year; R-2 = 0.79), suggesting that daytime R-E increased with increasing photosynthesis. Furthermore, the temperature sensitivity of R-E decreased from apparent Q(10) values of 3.3 to 3.9 by the classic equation to a more realistic Q(10...

  6. Organization of prefrontal network activity by respiration-related oscillations

    Science.gov (United States)

    Biskamp, Jonatan; Bartos, Marlene; Sauer, Jonas-Frederic

    2017-01-01

    The medial prefrontal cortex (mPFC) integrates information from cortical and sub-cortical areas and contributes to the planning and initiation of behaviour. A potential mechanism for signal integration in the mPFC lies in the synchronization of neuronal discharges by theta (6–12 Hz) activity patterns. Here we show, using in vivo local field potential (LFP) and single-unit recordings from awake mice, that prominent oscillations in the sub-theta frequency band (1–5 Hz) emerge during awake immobility in the mPFC. These oscillation patterns are distinct from but phase-locked to hippocampal theta activity and occur synchronized with nasal respiration (hence termed prefrontal respiration rhythm [PRR]). PRR activity modulates the amplitude of prefrontal gamma rhythms with greater efficacy than theta oscillations. Furthermore, single-unit discharges of putative pyramidal cells and GABAergic interneurons are entrained by prefrontal PRR and nasal respiration. Our data thus suggest that PRR activity contributes to information processing in the prefrontal neuronal network. PMID:28349959

  7. [The knowledge of animal respiration as a combustion phenomenon].

    Science.gov (United States)

    de Micheli, Alfredo

    2014-01-01

    The different stages leading to knowledge of the phenomenon of animal breathing are going from some writings in Corpus Hippocraticum to Aristoteles' and Galen's works, who considered the heart as the source of the animal heat. Later, Miguel Servet suggested that the inspired air can achieve other functions besides cooling the blood. After that, different explications of the animal heat were raised. About 1770, due to progress of knowledge in the chemistry field, first Mayow and later Black began to consider the animal respiration as a combustion. The important treatise Méthode de nomenclature chimique, published by Guyton de Morveau et al. in 1787 and soon after the Traité élémentaire de chimie de Lavoisier (1789) provided a solid support to Lavoisier's thought. This way on arrived to consider analogous the respiration and combustion phenomena. Studies on the animal respiration phenomenon continued in xix century and in the following century it was possible to apply thermodynamic principles to biology: "generalized thermodynamics".

  8. Infrared imaging based hyperventilation monitoring through respiration rate estimation

    Science.gov (United States)

    Basu, Anushree; Routray, Aurobinda; Mukherjee, Rashmi; Shit, Suprosanna

    2016-07-01

    A change in the skin temperature is used as an indicator of physical illness which can be detected through infrared thermography. Thermograms or thermal images can be used as an effective diagnostic tool for monitoring and diagnosis of various diseases. This paper describes an infrared thermography based approach for detecting hyperventilation caused due to stress and anxiety in human beings by computing their respiration rates. The work employs computer vision techniques for tracking the region of interest from thermal video to compute the breath rate. Experiments have been performed on 30 subjects. Corner feature extraction using Minimum Eigenvalue (Shi-Tomasi) algorithm and registration using Kanade Lucas-Tomasi algorithm has been used here. Thermal signature around the extracted region is detected and subsequently filtered through a band pass filter to compute the respiration profile of an individual. If the respiration profile shows unusual pattern and exceeds the threshold we conclude that the person is stressed and tending to hyperventilate. Results obtained are compared with standard contact based methods which have shown significant correlations. It is envisaged that the thermal image based approach not only will help in detecting hyperventilation but can assist in regular stress monitoring as it is non-invasive method.

  9. Betaine is a positive regulator of mitochondrial respiration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Icksoo, E-mail: icksoolee@dankook.ac.kr

    2015-01-09

    Highlights: • Betaine enhances cytochrome c oxidase activity and mitochondrial respiration. • Betaine increases mitochondrial membrane potential and cellular energy levels. • Betaine’s anti-tumorigenic effect might be due to a reversal of the Warburg effect. - Abstract: Betaine protects cells from environmental stress and serves as a methyl donor in several biochemical pathways. It reduces cardiovascular disease risk and protects liver cells from alcoholic liver damage and nonalcoholic steatohepatitis. Its pretreatment can rescue cells exposed to toxins such as rotenone, chloroform, and LiCl. Furthermore, it has been suggested that betaine can suppress cancer cell growth in vivo and in vitro. Mitochondrial electron transport chain (ETC) complexes generate the mitochondrial membrane potential, which is essential to produce cellular energy, ATP. Reduced mitochondrial respiration and energy status have been found in many human pathological conditions including aging, cancer, and neurodegenerative disease. In this study we investigated whether betaine directly targets mitochondria. We show that betaine treatment leads to an upregulation of mitochondrial respiration and cytochrome c oxidase activity in H2.35 cells, the proposed rate limiting enzyme of ETC in vivo. Following treatment, the mitochondrial membrane potential was increased and cellular energy levels were elevated. We propose that the anti-proliferative effects of betaine on cancer cells might be due to enhanced mitochondrial function contributing to a reversal of the Warburg effect.

  10. Automatic respiration monitoring system; Shushin jotai no jido monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This is a system to recognize automatically status of a person in sleep including respiration stop, toss about in bed, and departure from the bed by performing animated image processing on images of the person in sleep as photographed by a camera, and by obtaining respiration waveforms from changes in the images of the breast. The system has been developed jointly by the Medical Department of Ehime University and Toshiba Engineering Company when commissioned from the Silver Service Promotion Association as a two-year project. The system requires no operation by an operator, can monitor the respiration during sleep on a real time basis from a completely non-restraint condition, and can be utilized for early discovery of crib death and/or apneic syndrome of aged persons and infants. Its effectiveness was verified by the field tests at a special facility for physically and mentally handicapped aged persons. The system was awarded with the first grand prize for an image recognition system from the Japan Automatic Recognition System Association. (translated by NEDO)

  11. Effect of phosphogypsum on respiration and methane emissions in sediment.

    Science.gov (United States)

    DeLaune, R D; Porthouse, J D; Patrick, W H

    2006-05-01

    The impact of adding phosphogypsum (PG) to freshwater wetland areas, and potential effect on methane production and respiration in sediment was studied in the laboratory. Two organic matter levels (native and enriched with 0.5% by weight ground dry plant material) were studied using five sediment treatments each: (1) no PG added, (2) 4% PG by dry weight (homogenized), (3) 20% PG by dry weight (homogenized), (4) 2000 kg ha(-1) (surface applied), and (5) 5000 kg ha (surface applied), and the experiment was run in triplicate. There was a net flux of methane into sediment for all treatments that were maintained at the native organic matter level, indicating net methane oxidation. In the organic-enriched cores, both of the homogenized treatments exhibited no methane emissions, while the surface applied treatments retained the potential for high emissions. Soil respiration was depressed in all treatments when compared to controls, especially in the organic-enriched cores. The results conclude that it may be possible to add PG to non-vegetated areas with few observable effects on sediment respiration, but organic matter content and method of application are critical concerns.

  12. Cultivation of anaerobic and facultatively anaerobic bacteria from spacecraft-associated clean rooms.

    Science.gov (United States)

    Stieglmeier, Michaela; Wirth, Reinhard; Kminek, Gerhard; Moissl-Eichinger, Christine

    2009-06-01

    In the course of this biodiversity study, the cultivable microbial community of European spacecraft-associated clean rooms and the Herschel Space Observatory located therein were analyzed during routine assembly operations. Here, we focused on microorganisms capable of growing without oxygen. Anaerobes play a significant role in planetary protection considerations since extraterrestrial environments like Mars probably do not provide enough oxygen for fully aerobic microbial growth. A broad assortment of anaerobic media was used in our cultivation strategies, which focused on microorganisms with special metabolic skills. The majority of the isolated strains grew on anaerobic, complex, nutrient-rich media. Autotrophic microorganisms or microbes capable of fixing nitrogen were also cultivated. A broad range of facultatively anaerobic bacteria was detected during this study and also, for the first time, some strictly anaerobic bacteria (Clostridium and Propionibacterium) were isolated from spacecraft-associated clean rooms. The multiassay cultivation approach was the basis for the detection of several bacteria that had not been cultivated from these special environments before and also led to the discovery of two novel microbial species of Pseudomonas and Paenibacillus.

  13. Enhancing post anaerobic digestion of full-scale anaerobically digested sludge using free nitrous acid treatment.

    Science.gov (United States)

    Zhang, Tingting; Wang, Qilin; Ye, Liu; Yuan, Zhiguo

    2016-05-01

    In some wastewater treatment plants (WWTPs), the ever increasing production of sludge with the expanding population overloaded the anaerobic digestion which compromises the sludge reduction efficiency. Post anaerobic digestion of anaerobically digested sludge (ADS) has been applied to enhance sludge reduction, however, to a very limited extent. This study verified the effectiveness of free nitrous acid (FNA i.e. HNO2) pre-treatment on enhancing full-scale ADS degradation in post anaerobic digestion. The ADS collected from a full-scale WWTP was subject to FNA treatment at concentrations of 0.77, 1.54, 2.31, 3.08, and 3.85 mg N/L for 24 h followed by biochemical methane potential tests. The FNA treatment at all concentrations resulted in an increase (from 1.5-3.1 % compared to the control) in sludge reduction with the highest improvement achieved at 0.77 mg HNO2-N/L. The FNA treatment at this concentration also resulted in the highest increase in methane production (40 %) compared to the control. The economic analysis indicates that FNA treatment is economically attractive for enhancing post anaerobic digestion of full-scale ADS.

  14. Alkaline stability of quaternary ammonium cations for alkaline fuel cell membranes and ionic liquids.

    Science.gov (United States)

    Marino, M G; Kreuer, K D

    2015-02-01

    The alkaline stability of 26 different quaternary ammonium groups (QA) is investigated for temperatures up to 160 °C and NaOH concentrations up to 10 mol L(-1) with the aim to provide a basis for the selection of functional groups for hydroxide exchange membranes in alkaline fuel cells and of ionic-liquid cations stable in basic conditions. Most QAs exhibit unexpectedly high alkaline stability with the exception of aromatic cations. β-Protons are found to be far less susceptible to nucleophilic attack than previously suggested, whereas the presence of benzyl groups, nearby hetero-atoms, or other electron-withdrawing species promote degradation reactions significantly. Cyclic QAs proved to be exceptionally stable, with the piperidine-based 6-azonia-spiro[5.5]undecane featuring the highest half-life at the chosen conditions. Absolute and relative stabilities presented herein stand in contrast to literature data, the differences being ascribed to solvent effects on degradation.

  15. Conversion of Methanogenic Substrates in Anaerobic Reactors

    OpenAIRE

    Gonzalez-Gil, G.

    2000-01-01

    The EGSB systems represents an attractive option to extend further the use of anaerobic technology for wastewater treatment, particularly with respect to waste streams originating from chemical industries. Frequently chemical waste streams are unbalanced with respect to nutrients and/or micronutrients and furthermore these streams may contain toxic-biodegradable compounds. To reduce toxicity high recycle ratios may be applied as in the case of EGSB reactors however, this at the same time may ...

  16. Instrumentation and Control in Anaerobic Digestion

    DEFF Research Database (Denmark)

    has been lack of process control handles, instruments, and developed control algorithms. This has improved dramatically in the past 10 years, and all of these areas have now been addressed. The main gap in instrumentation technology has been a rapid intermediate sensor to detect overload conditions...... benchmark. There has therefore been, overall, a quantum advance in application and sophistication of instrumentation and control in anaerobic digestion, and it is an effective option for improved process loading rate and conversion efficiency....

  17. Anaerobic co-digestion of organic wastes

    OpenAIRE

    2009-01-01

    Tese de doutoramento em Engenharia Química e Biológica Anaerobic digestion is an already established process but the increasing need of bio‐waste recovery has determined the emergence of new substrates, revamping the research in this field. Contrary to some other European countries, in Portugal this technology is still scarcely in use. Nonetheless, the current legislation endorses this application as a waste management and as an energy recovery process. The rapid growth of the ...

  18. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;

    2003-01-01

    control approaches that have been used are comprehensively described. These include simple and adaptive controllers, as well as more recent developments such as fuzzy controllers, knowledge-based controllers and controllers based on neural networks.......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  19. Microbial Aspects of Anaerobic BTEX Degradation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Combined with conventional methods, developments in both geochemical (delineation of redox processes) and molecular microbial methods (analysis of 16S rDNA genes and functional genes) have allowed us to study in details microorganisms and genes involved in the anaerobic degradation of benzene, toluene, ethylbenzene and xylene (BTEX) under specific redox conditions. This review summarizes recent research in this field. The potential for anaerobic BTEX degradation is widely spread. Specific groups of microorganisms appear to be involved in degradation under different redox conditions. Members of the Azoarcus/Thauera cluster perform BTEX degradation under denitrifying conditions, Geobacteraceae under Fe (III) reducing conditions and Desulfobacteriaceae under sulfate reducing conditions. The information so far obtained on biochemistry and molecular genetics of BTEX degradation indicates that each BTEX compound is funneled into the central benzyol-CoA pathway by a different peripheral pathway. The peripheral pathways of per BTEX compound show similarities among different physiological groups of microorganisms. We also describe how knowledge obtained on the microbial aspects of BTEX degradation can be used to enhance and monitor anaerobic BTEX degradation.

  20. Vinasses treatment in anaerobic fludized bed reactor.

    Directory of Open Access Journals (Sweden)

    Francisco J. C. Terán

    2009-03-01

    Full Text Available The agricultural use of vinasse produced by the sugar industry has gone through many changes over the years. Coupled with concern over the increased agronomic efficiency and optimizing the management of the use of such waste, you can highlight the major global ecological awareness, developed after 90s. This study aims at the construction and operation of a reactor anaerobic cracker (RALF on pilot scale to verify the burden of chemical demand of oxygen (DQO of vinasse, under mesophilic. The stillage used for feeding the reactor was from a sugar cane processing plant, located in the city of Regente Feijó, São Paulo State. The inoculum was anaerobic sludge from a reactor and upward flow anaerobic sludge blanket (UASB treating wastewater from a factory of soda. The concentrations of vinasse to be treated ranged 17,239 mg DQO L-1 up to 28,174 mg DQO L-1. The effluent pH was maintained between 6.4 and 8.6 during the research. The productivity of biogas in the reactor has not achieved the expected rates, reaching only 46 mL day-1. Maximum efficiency attained during operation was 51.1 %, corresponding to a 14-day operation time, vinasses organic loading of 19.5 kg DQO m-3 dia-1 and to an hydraulic detention time of one day.