WorldWideScience

Sample records for cosubstrates mikrobiologischer abbau

  1. Microbiologically induced corrosion in sewage treatment plants. Final report; Mikrobiologisch induzierte Korrosion in Abwasserbehandlungsanlagen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The corrosion of welded noble steels in sewage treatment plants was investigated, with particular regard to microbiologically induced corrosion. Pitting corrosion as often observed in practical operation was induced experimentally in the materials 1.4201, 1.4306, and 1.4571. The pitting corrosion was caused by blooming the simultaneous presence of Mg-oxidating bacteria. Blooming must be prevented or removed in principle in steels. No corrosion was observed in the higher-alloyed steels 1.4462, 1.4529, and 1.4562. An annular column and a bioreactor were constructed on the laboratory scale in order to be able to carry out corrosion experiments with biologically active media. Methods for detecting micro-organisms were developed (epifluorescence microscopy). [German] Das Ziel des Projektes war die Ermittlung der Korrosionsgefaehrdung von geschweissten nichtrostenden Staehlen in Abwasserbehandlungsanlagen. Insbesondere der Einfluss einer mikrobiologisch beeinflussten Korrosion (MIK) auf die Bestaendigkeit geschweisster Rohrleitungen aus nichtrostendem Stahl wurde untersucht. Durch Auslagerungsversuche in einem Klaerwerk konnte an Schweissverbindungen mit Anlauffarben Lochkorrosion, die in der Praxis auftritt, reproduziert werden. Anfaellig sind die Werkstoffe 1.4301, 1.4306 und 1.4571. Ursache fuer die Lochkorrosion waren Anlauffarben bei gleichzeitiger Anwesenheit von manganoxidierenden Bakterien. Anlauffarben muessen bei den Staehlen grundsaetzlich verhindert oder entfernt werden. An hoeher legierten Staehlen wie 1.4462, 1.4529 und 1.4562 trat keine Korrosion auf. Im Labormassstab ist eine Ringsaeule und ein Bioreaktor gebaut worden, um Korrosionsversuche mit biologisch aktivem Medium durchfuehren zu koennen. Methoden zum Nachweis von Mikroorganismen sind erarbeitet worden (Epifluoreszenzmikroskopie). (orig.)

  2. Development of bio-active permeable in-situ barriers for plume remediation. Subproject 1: long term-behaviour of contaminant release from NAPL sources and contaminant retardation in sorbing barriers. Subproject 2: biological pollutant degradation. Final report; VEGAS - Entwicklung bioaktiver Sorptionsbarrieren zur in-situ Abstromsanierung. Teilprojekt 1: Langzeit-Entwicklung der Schadstoffemission aus Schadensherden und Schadstoff-Retention in Sorptionsbarrieren. Teilprojekt 2: Mikrobiologischer Schadstoffabbau in Sorptionsbarrieren und Schadensherden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Teutsch, G.; Grathwohl, P.; Liedl, R.; Eberhardt, C.; Finkel, M.; Kuehn, W.; Stieber, M.; Linke, C.

    2001-09-15

    Tensideeinsatzes, der mikrobiologische Abbau sowie der Stofftransport im Abstrom bildeten die Schwerpunkte der Untersuchungen. Die wichtigsten Ergebnisse des Forschungsvorhabens sind: - Keines der 6 untersuchten Tenside erfuellt die Voraussetzungen fuer den Aufbau einer stabilen Sorptionssperre. - PAK- und BTEX-Abbau konnten durch Zugabe von H{sub 2}O{sub 2} (auch in Kombination mit Nitrat) deutlich gesteigert werden. Unter anaeroben Bedingungen konnte jedoch kein PAK-Abbau festgestellt werden. Von BTEX wurde nur Ethylbenzol umgesetzt. - Die Schadstofffreisetzung aus Teeroel-Pools und die resultierenden Konzentrationsprofile konnten erstmals messtechnisch erfasst und quantifiziert werden. Porendiffusion und transversale Dispersion steuern die Schadstofffreisetzung. - Durch den Einsatz der 'baugleichen' Tenside Lutensol A8 und Terrasurf G50 konnten die Schadstofffrachten um ein Vielfaches gesteigert werden. (z.B. Phenanthren um mehr als das 20-fache), wobei gleichzeitig durch moderate Tensid-Konzentrationen ({proportional_to}1 g/l) eine Mobilisierung weitestgehend vermieden werden konnte. - Durch den erhoehten Bedarf an Elektronenakzeptoren fuer den Tensidabbau konnten die erhoehten Schadstofffrachten nicht durch mikrobiellen Abbau eliminiert werden. - Innerhalb der Schadstofffahne findet aufgrund der diffusionslimitierten Schadstoffdesorption nur eine geringe PAK-Solubilisierung statt. (orig.)

  3. Reciprocal C-13-labeling: A method for investigating the catabolism of cosubstrates

    DEFF Research Database (Denmark)

    Christensen, B.; Nielsen, Jette

    2002-01-01

    The principle of reciprocal labeling is to use a uniformly C-13-labeled substrate as the primary carbon source and a naturally labeled cosubstrate. Metabolites derived from a naturally labeled cosubstrate, in this case amino acids, can then be identified by their relatively lower content of C-13,...

  4. More efficient redox biocatalysis by utilizing 1,4-butanediol as a ‘smart cosubstrate'

    NARCIS (Netherlands)

    Kara, S.; Spickermann, D.; Schrittwieser, J.H.; Leggewie, C.; Berkel, van W.J.H.; Arends, I.W.C.E.; Hollmann, F.

    2013-01-01

    1,4-Butanediol is shown to be an efficient cosubstrate to promote NAD(P)H-dependent redox biocatalysis. The thermodynamically and kinetically inert lactone coproduct makes the regeneration reaction irreversible. Thereby not only the molar surplus of cosubstrate is dramatically reduced but also faste

  5. Investigations into the photochemical degradation of biogenic and anthropogeneous halogenated hydrocarbons in seawater; Untersuchungen zum photochemischen Abbau von biogenen und anthropogenen halogenierten Kohlenwasserstoffen im Meerwasser

    Energy Technology Data Exchange (ETDEWEB)

    Faller, J.T.

    1992-05-20

    Bromoform and hexachloro-cyclohexane in seawater were studied for their possible degradation. Bromoform is demonstrably degraded through the effect of sunlight. Hydrogen peroxide present in seawater contributes to the acceleration of this effect. The second compound investigated is also photochemically degraded in seawater. This degradation mechanism is described in the paper. Increased temperature and the presence of hydrogen peroxide accelerate the degradation. (VT) [Deutsch] Bromoform und Hexachlorcyclohexan im Meerwasser sollten auf ihren moeglichen Abbau untersucht werden. Bromoform wird nachweisbar durch Einwirkung von Sonnenlicht abgebaut. Zur Beschleunigung der Reaktion traegt das im Seewasser anwesende Wasserstoffperoxid bei. Die zweite untersuchte Verbindung wird im Meer ebenfalls photochemisch abgebaut. Der Mechanismus des Abbaus ist in der Arbeit beschrieben. Die Temperaturerhoehung und die Anwesenheit des Wasserstoffperoxids beschleunigen den Abbau. (VT)

  6. Bioelectro-Claus processes using MFC technology: Influence of co-substrate.

    Science.gov (United States)

    Raschitor, A; Soreanu, G; Fernandez-Marchante, C M; Lobato, J; Cañizares, P; Cretescu, I; Rodrigo, M A

    2015-01-01

    This work is focused on the removal of sulphide from wastewater using a two chamber microbial fuel cell, seeded with activated sludge and operated in semi-continuous mode. Two co-substrates were used in order to provide the system for carbon and nutrient source: actual urban wastewater and synthetic wastewater. Results show that sulphide is efficiency depleted (removals over 94%) and that electricity is efficiently produced (maximum power density is 150 mW m(-2)) meanwhile COD is also oxidised (removals higher than 60%). Sulphur and sulphate are obtained as the final products of the oxidation and final speciation depends on the type of co-substrate used. The start-up of the system is very rapid and production of electricity and polarisation curves do not depend on the co-substrate.

  7. Decolorization of Orange Ⅱ using an anaerobic sequencing batch reactor with and without co-substrates

    Institute of Scientific and Technical Information of China (English)

    Soon-An Ong; Eiichi Toorisaka; Makoto Hirata; Tadashi Hano

    2012-01-01

    We investigated the decolorization of Orange Ⅱ with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor (ASBR).The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange H-containing wastewater enhanced color removal from 27% to 81% to 89%,respectively.In the absence of co-substrates and nutrients,more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange Ⅱ.The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR,which was important for the reduction of the Orange Ⅱ azo bond that caused decolorization.The maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.

  8. Influence of co-substrates in the anaerobic degradation of an anionic surfactant

    Directory of Open Access Journals (Sweden)

    D. Y. Okada

    2013-09-01

    Full Text Available The removal of linear alkylbenzene sulfonate (LAS was evaluated in a UASB reactor using short-chain alcohols (ethanol and methanol and complex co-substrate (yeast extract. Using only methanol and ethanol as co-substrates resulted in removal of LAS between 30 and 41%. At the end, addition of a complex substrate (yeast extract increased the removal of LAS to 50%. During the assay, water supply aeration increased the volatile fatty acid of the effluent (70 mg HAc.L-1 and decreased the removal of LAS (from 40 to 30%. According to the fluorescence in situ hybridization (FISH results, the amount of Archaea decreased due to water supply aeration (from 64 to 48%. Furthermore, addition of complex co-substrate increased the total anaerobic bacteria and methanogenic archaea content (three and four log units, respectively, which were estimated using the most probable number technique.

  9. Influence of co-substrate on textile wastewater treatment and microbial community changes in the anaerobic biological sulfate reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Rasool, Kashif; Mahmoud, Khaled A. [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO BOX 5825, Doha (Qatar); Lee, Dae Sung, E-mail: daesung@knu.ac.kr [Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701 (Korea, Republic of)

    2015-12-15

    Highlights: • Textile wastewater treatment performance was investigated with different co-substrates. • Dye biodegradation and biotransformation enhanced with lactate as co-substrate. • Sulfate removal significantly decreased under limited co-substrate concentration. • Changes in microbial community structure were studied using bar-coded pyrosequencing. • Lactate as co-substrate showed the highest relative abundance of sulfate reducing bacteria. - Abstract: This study investigated the anaerobic treatment of sulfate-rich synthetic textile wastewater in three sulfidogenic sequential batch reactors (SBRs). The experimental protocol was designed to examine the effect of three different co-substrates (lactate, glucose, and ethanol) and their concentrations on wastewater treatment performance. Sulfate reduction and dye degradation were improved when lactate and ethanol were used as electron donors, as compared with glucose. Moreover, under co-substrate limited concentrations, color, sulfate, and chemical oxygen demand (COD) removal efficiencies were declined. By reducing co-substrate COD gradually from 3000 to 500 mg/L, color removal efficiencies were decreased from 98.23% to 78.46%, 63.37%, and 69.10%, whereas, sulfate removal efficiencies were decreased from 98.42%, 82.35%, and 87.0%, to 30.27%, 21.50%, and 10.13%, for lactate, glucose, and ethanol fed reactors, respectively. Fourier transform infrared spectroscopy (FTIR) and total aromatic amine analysis revealed lactate to be a potential co-substrate for further biodegradation of intermediate metabolites formed after dye degradation. Pyrosequencing analysis showed that microbial community structure was significantly affected by the co-substrate. The reactor with lactate as co-substrate showed the highest relative abundance of sulfate reducing bacteria (SRBs), followed by ethanol, whereas the glucose-fed reactor showed the lowest relative abundance of SRB.

  10. ENHANCED ENZYMATIC REMOVAL OF CHLOROPHENOLS IN THE PRESENCE OF CO-SUBSTRATES. (R823847)

    Science.gov (United States)

    The effect of reactive co-substrates such as guaiacol and 2,6-dimethoxyphenol on the removal of chlorinated phenols by horseradish peroxidase (HRP) and alaccase from the fungus Trametes versicolor was investigated. Addition of 50 mM guaiacol enhanced the precipitation of 4-ch...

  11. Waste sizing solution as co-substrate for anaerobic decolourisation of textile dyeing wastewaters

    NARCIS (Netherlands)

    Bisschops, I.; Santos, dos A.B.; Spanjers, H.

    2005-01-01

    Dyeing wastewaters and residual size are textile factory waste streams that can be treated anaerobically. For successful anaerobic treatment of dyeing effluents, a co-substrate has to be added because of their low concentration of easily biodegradable compounds. Starch-based size contains easily bio

  12. Wet and Dry Anaerobic Digestion of Biowaste and of Co-substrates

    OpenAIRE

    Li, Chaoran

    2015-01-01

    Treatment of municipal solid waste by anaerobic digestion can solve the environmental problems caused by this organic solid waste and also supply biogas as renewable energy for a sustainable development. In this study the improvement of wet anaerobic digestion by addition of co-substrates and the effect of moisture on dry anaerobic digestion were investigated.

  13. Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Miethe, D.; Riis, V.; Stimming, M.

    1996-01-04

    It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen

  14. Biodegradation of complexing agents of the amino polycarbonic acid types by specifically adapted bacteria; Biologischer Abbau von Komplexbildnern des Aminopolycarbonsaeuretyps durch speziell adaptierte Bakterien

    Energy Technology Data Exchange (ETDEWEB)

    Potratz, W.; Baass, A.C.; Noertemann, B.; Hempel, D.C. [Inst. fuer Bioverfahrenstechnik der TU Braunschweig, Braunschweig (Germany)

    2003-07-01

    Amino polycarbonic acids (APC) are chelating agents of which large amounts are used, e.g., in the paper industry (diethylene triamino tetraacetate, DTPA) or photoindustry (ethylene diamino tetraacetate, EDTA; propylene diamino tetraacetate, PDTA). In contrast to nitrilotriacetate (NTA), EDTA, PDTA and DTAPA are not biodegradable. A new type of bacterium was recently cultivated which is capable of degrading EDTA and also PDTA. (orig.) [German] Aminopolycarbonsaeuren (APC) sind Chelatbildner (chele, griech: Krebsschere), die in grossen Mengen u.a. in der Papier- (Diethylentriamintetraacetat, DTPA) oder Fotoindustrie (Ethylendiamintetraacetat, EDTA; Propylendiamintetraacetat, PDTA) eingesetzt werden. Im Gegensatz zu der ebenfalls in grossen Mengen verwendeten APC Nitrilotriacetat (NTA) gelten EDTA, PDTA und DTPA als biologisch nicht abbaubar. Fuer den Abbau von EDTA konnte jedoch eine geeignete Bakterienmischkultur angereichert werden. Diese Kultur verwertet nicht nur EDTA, sondern auch gleichzeitig das in den Bleich-Fixierbaedern der Fotoindustrie ebenfalls eingesetzte PDTA. (orig.)

  15. Forage as co-substrate for biomethanation; Futtergraeser als Kosubstrat fuer die Biomethanisierung

    Energy Technology Data Exchange (ETDEWEB)

    Maehnert, P. [Humboldt Univ. zu Berlin, Landwirtschaftliche-Gaertnerische Fakultaet, Berlin (Germany); Schelle, H. [Abt. Bioverfahrenstechnik, Inst. fuer Agrartechnik Bornim, Potsdam (Germany); Heiermann, M. [Abt. Technikbewertung und Stoffkreislaeufe, Inst. fuer Agrartechnik Bornim, Potsdam (Germany)

    2002-07-01

    Because of the decreasing importance of forage as feed supply for dairy cattle interest is growing in alternative uses of grasslands. An ecological sound option is the fermentation of the material as co-substrates in biogas plants. Eight fresh-cut grass species and their silages were investigated for their methane production potential. The biogas production measured amounts to 0.71-0.86 m{sup 3.}kg{sup -1} ODM after a 28-day period. The according methane values are 0.28-0.46 m{sup 3.}kg{sup -1} ODM. The methane yields seem to be independent neither on species nor on conservation stage. (orig.)

  16. Degradation of toxaphene by Bjerkandera sp. strain BOL13 using waste biomass as a cosubstrate.

    Science.gov (United States)

    Lacayo Romero, Martha; Terrazas, Enrique; van Bavel, Bert; Mattiasson, Bo

    2006-07-01

    The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of beta-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.

  17. Degradation of organic pollutants in sewage sludge by aerobic-thermophilic sludge treatment. Final report; Abbau organischer Schadstoffe im Klaerschlamm durch aerob-thermophile Schlammbehandlung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Prechtl, S.

    1999-07-01

    Klaerschlamm. Im organischen Anteil des Klaerschlammfeststoffes sind bis heute ueber 300 verschiedene organische Spurenstoffe nachgewiesen worden. Neben den in der Klaerschlammverordnung erfassten Stoffgruppen (Dioxine/Furane und PCB) sind weitere Stoffgruppen als relevant eingestuft worden. Um die in diesem Bereich z.T. noch unzureichende Datenlage zu erweitern wurde im Forschungsvorhaben die Moeglichkeit untersucht, durch eine aerob-thermophile Schlammbehandlung (ATS) eine Verbesserung der Klaerschlammqualitaet, bei der Stoffgruppe der Phthalate (Di-(2-ethylhexyl)phthalat), den polyzklischen aromatischen Kohlenwasserstoffen (PAK) und beim 4-Nonylphenol (Abbauprodukt von nichtionischen Tensiden), zu erreichen. Zur Beurteilung der Abbaueffektivitaet aus der komplexen Matrix Klaerschlamm bildete die Schadstoffanalytik mittels HPLC und GC/MS einen Schwerpunkt des Vorhabens. Der Gehalt an Di-(2-ethylhexyl)phthalat (DEHP) und 4-Nonylphenol (4-NP) konnte in Laborversuchen mit dotierten Schlaemmen um 70% bzw. 50% und in undotierten Schlaemmen um 61% bzw. 53% reduziert werden. Bei halbtechnischen Versuchen lag die Reduktion fuer DEHP bei 14% und fuer 4-NP bei 68%. Fuer Pyren liess sich in Laborversuchen ein Abbau bis zu 57% erreichen, im Vergleich zu halbtechnischen Untersuchungen mit 22% Abbau. Die Ergebnisse erster grundlegender Untersuchungen zu einer Verfahrenskombination aus verkuerzter Faulstufe und ATS-Folgestufe zeigten fuer DEHP eine Reduktion von ca. 60%. Der Gehalt an einzelnen PAK konnten bis Anthracen reduziert werden. Fuer hoeherkondensierte PAK (Grundbelastung im ppb-Bereich) ergab sich keine einheitliche Aussage. Ein Abbau von 4-NP wurde bei den Versuchen zur Verfahrenskombination durch die Neubildung von 4-NP aus Alkylphenolethoxylaten unter anaeroben und aeroben Bedingungen ueberdeckt. Die erhaltenen Untersuchungsergebnisse bestaetigen die Korrelation zwischen einer Hygienisierung des Klaerschlamms und der entsprechenden Verweilzeit im Reaktorsystem. Sowohl in der

  18. Economic analyses of agricultural co-substrates for use in biogas plants; Wirtschaftlichkeitsuntersuchungen zum Einsatz landwirtschaftlicher Kosubstrate in Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, P.; Ploechl, M.; Heiermann, M. [Inst. fuer Agrartechnik Bornim, Abt. Technikbewertung und Stoffkreislaeufe, Potsdam (Germany)

    2002-07-01

    The study analyses the effect of different factors (yields, production costs, methane yields, amount of co-substrates, investment costs and economies of scale) on the profitability of crops as inputs in biogas production plants. The profitability of silages from perennial ryegrass, alfalfa, maize and barley varies mainly within positive economic results, while rapeseed, hemp and topinambur mainly present a range of negative results. Fresh rye and silages from rye and wheat show equal positive and negative variation of results. Even the economic result of biogas plants is determined by investment costs, the sum of effects resulting from variations of yields, co-substrate production costs, amount of co-substrates, methane yields and economies of scales is decisive for the profitability of biogas plants. (orig.)

  19. Effect of co-substrates on biogas production and anaerobic decomposition of pentachlorophenol.

    Science.gov (United States)

    Khan, Mohammad Danish; Khan, Nishat; Nizami, Abdul-Sattar; Rehan, Mohammad; Sabir, Suhail; Khan, Mohammad Zain

    2017-08-01

    This study aims to examine the effect of different co-substrates on the anaerobic degradation of pentachlorophenol (PCP) with simultaneous production of biogas. Acetate and glucose were added as co-substrates to monitor and compare the methanogenic reaction during PCP degradation. During the experiment, a chemical oxygen demand (COD) removal efficiency of 80% was achieved. Methane (CH4) production was higher in glucose-fed anaerobic reactors with the highest amount of CH4 (303.3µL) produced at 200ppm of PCP. Scanning electron microscopy (SEM) demonstrates the high porous structure of anaerobic sludge with uniform channels confirming better mass transfer and high PCP removal. Quantitative real-time PCR (qPCR) revealed that methanogens were the dominating species while some sulfate reducing bacteria (SRBs) were also found in the reactors. The study shows that strategic operation of the anaerobic reactor can be a feasible option for efficient degradation of complex substrates like PCP along with the production of biogas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Production of biogas from poultry litter mixed with the co-substrate cow dung

    Directory of Open Access Journals (Sweden)

    Mohammad Roman Miah

    2016-07-01

    Full Text Available Poultry litter (a mixture of rice hulls, sawdust and chicken excreta of broilers mixed with the co-substrate cow dung and poultry droppings was evaluated under anaerobic conditions for the production of biogas (methane. Four laboratory scale reactors, R1, R2, R3 and R4, were set up with different proportions of waste poultry litter, cow dung and poultry droppings and had a 6% total solid concentration. Digestion was carried out for 50 days at room temperature, 32 ± 3 °C. Volatile solid degradation and specific gas production in the four reactors was 46%, 51.99%, 51.96%, 43% and 0.263, 0.469, 0.419, 0.221 l/g, respectively, based on the volatile solid (VS feed. The methane yields were 71%, 72.5%, 72.6% and 70%, respectively. The COD reductions were 46.1%, 50.76%, 48.23% and 45.12%, respectively. A kinetic analysis showed that the anaerobic digestion of poultry litter with a co-substrate followed first order kinetics. Among the experimental reactors, R2 (25% cow dung, 75% poultry litter gave the optimum results: a VS reduction of 51.99%, a specific gas yield of 0.469 l/g and a methane yield of 72.5%.

  1. Choosing co-substrates to supplement biogas production from animal slurry - A life cycle assessment of the environmental consequences

    DEFF Research Database (Denmark)

    Croxatto Vega, Giovanna Catalina; Ten Hoeve, Marieke; Birkved, Morten

    2014-01-01

    nutrient content and high methane potential, straw yields the lowest impacts for eutrophication and the highest climate change and fossil depletion savings. Co-substrates diverted from incineration to biogas production had fewer environmental benefits, due to the loss of energy production, which...... is then produced from conventional fossil fuels. The scenarios can often provide benefits for one impact category while causing impacts in another.......Biogas production from animal slurry can provide substantial contributions to reach renewable energy targets, yet due to the low methane potential of slurry, biogas plants depend on the addition of co-substrates to make operations profitable. The environmental performance of three underexploited co...

  2. Choosing co-substrates to supplement biogas production from animal slurry--a life cycle assessment of the environmental consequences.

    Science.gov (United States)

    Croxatto Vega, Giovanna Catalina; ten Hoeve, Marieke; Birkved, Morten; Sommer, Sven G; Bruun, Sander

    2014-11-01

    Biogas production from animal slurry can provide substantial contributions to reach renewable energy targets, yet due to the low methane potential of slurry, biogas plants depend on the addition of co-substrates to make operations profitable. The environmental performance of three underexploited co-substrates, straw, organic household waste and the solid fraction of separated slurry, were assessed against slurry management without biogas production, using LCA methodology. The analysis showed straw, which would have been left on arable fields, to be an environmentally superior co-substrate. Due to its low nutrient content and high methane potential, straw yields the lowest impacts for eutrophication and the highest climate change and fossil depletion savings. Co-substrates diverted from incineration to biogas production had fewer environmental benefits, due to the loss of energy production, which is then produced from conventional fossil fuels. The scenarios can often provide benefits for one impact category while causing impacts in another. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Assessment of Gardening Wastes as a Co-Substrate for Diapers Degradation by the Fungus Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Rosa María Espinosa-Valdemar

    2015-05-01

    Full Text Available Waste with high biomass content generated in cities in developing countries is sent to landfills or open dumps. This research aims to degrade biomass content in urban waste through cultivation, at pilot scale, of the edible mushroom Pleurotus ostreatus. First, the number of diapers used by one baby per week was measured with a survey in day care facilities. Then, cellulose content of diapers was assessed. Finally, cultivation of P. ostreatus was carried out using as substrate a mixture of diapers with gardening waste, a co-substrate readily available at urban settings. The factors assessed were strain of P. ostreatus (grey BPR-81, white BPR-5, conditioning of the substrate (diapers with and without plastic and co-substrate (wheat straw, grass, and withered leaves. Results show that diapers are a valuable source of biomass, as generation of diapers with urine is 15.3 kg/child/month and they contain 50.2% by weight of cellulose. The highest reductions in dry weight and volume (>64% of substrates was achieved with the substrate diaper without plastic and co-substrate wheat straw. Although diapers with plastic and grass and leaves showed lower degradation, they achieved efficiencies that make them suitable as a co-substrate (>40%, considering that their biomass is currently confined in landfills.

  4. Anaerobic Degradation of Tetrachloroethylene Using Different Co-substrates as Electron Donors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To investigate the biodegradation of tetrachloroethylene (PCE) by acclimated anaerobic sludge using different co-substrates, I.e., glucose, acetate, and lactate as electron donors. Methods HP-6890 gas chromatograph (GC) in combination with auto-sampler was used to analyze the concentration of PCE and its intermediates. Results PCE could be degraded by reductive dechlorination and the degradation reaction conformed to the first-order kinetic equation. The rate constants are k1actate>kglucose>kacetate. The PCE degradation rate was the highest in the presence of lactate as an electron donor.Conclusion Lactate is the most suitable electron donor for PCE degradation and the electron donors supplied by co-metabolic substrates are not the limiting factors for PCE degradation.

  5. Anaerobic Codigestion of Sludge: Addition of Butcher's Fat Waste as a Cosubstrate for Increasing Biogas Production.

    Science.gov (United States)

    Martínez, E J; Gil, M V; Fernandez, C; Rosas, J G; Gómez, X

    2016-01-01

    Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations.

  6. The effect of maize silage as co-substrate for swine manure on the bacterial community structure in biogas plants.

    Science.gov (United States)

    Fliegerová, K; Mrázek, J; Kajan, M; Podmirseg, S M; Insam, H

    2012-07-01

    The qualitative and quantitative changes in the bacterial community composition in two mesophilic, commercially used biogas plants were monitored by denaturing gradient gel electrophoresis (DGGE) and real-time PCR. The main objective was to evaluate the influence of the co-substrate maize silage on total bacteria and some selected bacterial groups by comparing full-scale reactors fed solely with pig manure or additionally with maize silage. DGGE fingerprints reflected shifts in the bacterial community structure associated with maize silage as co-substrate and the real-time PCR results showed clear changes in the quantitative composition of the bacterial consortia of each fermenter. A clear dominance of Clostridia in all surveyed fermenters and considerably lower abundance of Bacteroidetes in the biogas plant fed with maize silage was shown.

  7. Crystal structures and molecular dynamics simulations of thermophilic malate dehydrogenase reveal critical loop motion for co-substrate binding.

    Science.gov (United States)

    Hung, Chih-Hung; Hwang, Tzann-Shun; Chang, Yu-Yung; Luo, Huei-Ru; Wu, Szu-Pei; Hsu, Chun-Hua

    2013-01-01

    Malate dehydrogenase (MDH) catalyzes the conversion of oxaloacetate and malate by using the NAD/NADH coenzyme system. The system is used as a conjugate for enzyme immunoassays of a wide variety of compounds, such as illegal drugs, drugs used in therapeutic applications and hormones. We elucidated the biochemical and structural features of MDH from Thermus thermophilus (TtMDH) for use in various biotechnological applications. The biochemical characterization of recombinant TtMDH revealed greatly increased activity above 60 °C and specific activity of about 2,600 U/mg with optimal temperature of 90 °C. Analysis of crystal structures of apo and NAD-bound forms of TtMDH revealed a slight movement of the binding loop and few structural elements around the co-substrate binding packet in the presence of NAD. The overall structures did not change much and retained all related positions, which agrees with the CD analyses. Further molecular dynamics (MD) simulation at higher temperatures were used to reconstruct structures from the crystal structure of TtMDH. Interestingly, at the simulated structure of 353 K, a large change occurred around the active site such that with increasing temperature, a mobile loop was closed to co-substrate binding region. From biochemical characterization, structural comparison and MD simulations, the thermal-induced conformational change of the co-substrate binding loop of TtMDH may contribute to the essential movement of the enzyme for admitting NAD and may benefit the enzyme's activity.

  8. Selectivity of Rhizomucor miehei lipase as affected by choice of cosubstrate system in ester modification reactions in organic media.

    Science.gov (United States)

    Arsan, J; Parkin, K L

    2000-07-20

    Fatty acid (FA) selectivity of immobilized Rhizomucor miehei lipase was determined for various cosubstrate systems for ester modification involving competing n-acyl-donor substrates of even-chain length (C4-C16; FA or their methyl esters, FAME) and either n-propanol or propyl acetate in hexane. Acyl-chain-length optima were observed for C8 and C14/16 in all cases. Upon changing between cosubstrate systems of [FA + propanol] to [FAME + propanol] to [FAME + propyl acetate], there was a general shift in selectivity toward shorter-chain-length FA (C4-C8). The greatest degree of reaction selectivity (based on ratios of selectivity constants) among the FA substrates was 3.1 for the [FA + propanol], 2.5 for the [FAME + propanol], and 1.4 for the [FAME + propyl acetate] cosubstrate systems. For esterification reactions between C6 FA and reactive members of a series of aliphatic and aromatic alcohols, the greatest degree of selectivity observed was 3.6.

  9. ENHANCED BIOGAS PRODUCTION FROM POULTRY DROPPINGS USING CORN-COB AND WASTE PAPER AS CO-SUBSTRATE.

    Directory of Open Access Journals (Sweden)

    AREMU, M .O

    2013-02-01

    Full Text Available The rising cost of conventional fuel in urban areas have necessitates the exploration of other cheap, renewable and sustainable alternative energy sources. This study investigates the potential of plant and animal wastes for biogas production at laboratory scales. The study was carried out through anaerobic fermentation using poultry droppings as main substrate and corn-cob and waste papers as co-substrate. The fermentation was carried out at temperatures between 27 – 35 °C and pH range of 4.2 – 8.0 for a period of 30 days. The results showed that poultry droppings alone in bio-digester A gave a cumulative average biogas volume of 3452 cm3 (115 cm3 day-1 and poultry droppings plus untreated co-substrates in bio-digester B gave a cumulative average biogas volume of 4811 cm3 (160.3 cm3 day-1 while poultry droppings plus treated co-substrates in bio-digesters C gave a cumulative average biogas volume of 6454 cm3 (215.1 cm3 day-1.

  10. Biochemical conversion of sugarcane straw hemicellulosic hydrolyzate supplemented with co-substrates for xylitol production.

    Science.gov (United States)

    Hernández-Pérez, A F; Costa, I A L; Silva, D D V; Dussán, K J; Villela, T R; Canettieri, E V; Carvalho, J A; Soares Neto, T G; Felipe, M G A

    2016-01-01

    Biotechnological production of xylitol is an attractive route to add value to a sugarcane biorefinery, through utilization of the hemicellulosic fraction of sugarcane straw, whose availability is increasing in Brazil. Herein, supplementation of the sugarcane straw hemicellulosic hydrolyzate (xylose 57gL(-1)) with maltose, sucrose, cellobiose or glycerol was proposed, and their effect as co-substrates on xylitol production by Candida guilliermondii FTI 20037 was studied. Sucrose (10gL(-1)) and glycerol (0.7gL(-1)) supplementation led to significant increase of 8.88% and 6.86% on xylose uptake rate (1.11gL(-1)h(-1) and 1.09gL(-1)), respectively, but only with sucrose, significant increments of 12.88% and 8.69% on final xylitol concentration (36.11gL(-1)) and volumetric productivity (0.75gL(-1)h(-1)), respectively, were achieved. Based on these results, utilization of complex sources of sucrose, derived from agro-industries, as nutritional supplementation for xylitol production can be proposed as a strategy for improving the yeast performance and reducing the cost of this bioprocess by replacing more expensive nutrients.

  11. Optimised biogas production from microalgae through co-digestion with carbon-rich co-substrates.

    Science.gov (United States)

    Herrmann, Christiane; Kalita, Navajyoti; Wall, David; Xia, Ao; Murphy, Jerry D

    2016-08-01

    Microalgae can be used to upgrade biogas to biomethane and subsequently be digested for biogas production. However, the low C:N ratio of species such as Arthrospira platensis may cause ammonia inhibition and low process stability during anaerobic digestion. This study investigates co-fermentation of A. platensis with carbon-rich co-substrates (barley straw, beet silage and brown seaweed) at a C:N ratio of 25 to enhance biomass conversion. No synergistic effects on biomethane potential could be proven in batch fermentation tests. However continuous digestion trials showed significantly improved process stability. Mono-digestion of A. platensis was stable only at an organic loading of 1.0gVSL(-1)d(-1). The optimum process co-digested A. platensis with seaweed and achieved stable operation at an organic loading of 4.0gVSL(-1)d(-1). Co-digestion of microalgae and seaweed can be effectively applied to integrated coastal biomethane systems.

  12. Structure and function of Plasmodium falciparum malate dehydrogenase: role of critical amino acids in co-substrate binding pocket.

    Science.gov (United States)

    Pradhan, Anupam; Tripathi, Abhai K; Desai, Prashant V; Mukherjee, Prasenjit K; Avery, Mitchell A; Walker, Larry A; Tekwani, Babu L

    2009-01-01

    The malaria parasite thrives on anaerobic fermentation of glucose for energy. Earlier studies from our laboratory have demonstrated that a cytosolic malate dehydrogenase (PfMDH) with striking similarity to lactate dehydrogenase (PfLDH) might complement PfLDH function in Plasmodium falciparum. The N-terminal glycine motif, which forms a characteristic Rossman dinucleotide-binding fold in the co-substrate binding pocket, differentiates PfMDH (GlyXGlyXXGly) from other eukaryotic and prokaryotic malate dehydrogenases (GlyXXGlyXXGly). The amino acids lining the co-substrate binding pocket are completely conserved in MDHs from different species of human, primate and rodent malaria parasites. Based on this knowledge and conserved domains among prokaryotic and eukaryotic MDH, the role of critical amino acids lining the co-substrate binding pocket was analyzed in catalytic functions of PfMDH using site-directed mutagenesis. Insertion of Ala at the 9th or 10th position, which converts the N-terminal GlyXGlyXXGly motif (characteristic of malarial MDH and LDH) to GlyXXGlyXXGly (as in bacterial and eukaryotic MDH), uncoupled regulation of the enzyme through substrate inhibition. The dinucleotide fold GlyXGlyXXGly motif seems not to be responsible for the distinct affinity of PfMDH to 3-acetylpyridine-adenine dinucleotide (APAD, a synthetic analog of NAD), since Ala9 and Ala10 insertion mutants still utilized APADH. The Gln11Met mutation, which converts the signature glycine motif in PfMDH to that of PfLDH, did not change the enzyme function. However, the Gln11Gly mutant showed approximately a 5-fold increase in catalytic activity, and higher susceptibility to inhibition with gossypol. Asn119 and His174 participate in binding of both co-substrate and substrate. The Asn119Gly mutant exhibited approximately a 3-fold decrease in catalytic efficiency, while mutation of His174 to Asn or Ala resulted in an inactive enzyme. These studies provide critical insights into the co-substrate

  13. Investigations into the acceleration of microbial degradation of PAH in soils with high PAH contamination by coffein in practical conditions. Central analytical procedure and microbial effects; Untersuchungen zur Beschleunigung des mikrobiellen Abbaus von polycyclischen aromatischen Kohlenwasserstoffen in Boeden mit hoher PAH-Kontamination durch Coffein unter Praxisbedingungen. Teilprojekt A und B. Zentrale Analytik und mikrobiologische Begleituntersuchungen. Entwicklung einer optimalen Anwendungstechnik sowie oekonomische Evaluierung in Relation zu bestehenden Verfahren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grimmer, G.; Collins, H.J.; Muennich, K.

    1998-01-01

    PAH degradation by Mucor circinelloides was proved several times in the course of this project. Although PAH contamination could never be completely removed, a number of parameters were identified that influence successful PAH degradation, e.g. soil homogeneity, oxygen supply to the microorganisms, pH, and nutrient supply. The effect of the complexing agent coffein on PAH degradation, which had been described already in preliminary investigations, was validated several times. Optimisation experiments showed that the pre-determined optimum coffein concentration of 0.3% in the nutrient broth provided the best results also in the present investigation. There was no suggestion of a negative effect of various cations on the growth of Mucor circinelloides which may be mobilized in the soils by the acid nutrient broth. (orig./SR) [Deutsch] Im Rahmen dieses Projektes konnte der Abbau von PAH durch Mucor circinelloides mehrfach nachgewiesen werden. Es wurde in keinem Fall eine vollstaendige Entfernung der PAH-Kontamination erreicht, jedoch stellten sich eine Reihe von Parametern als wesentlich fuer einen erfolgreichen PAH-Abbau heraus (Homogenitaet des Bodenmaterials, Versorgung der Mikroorganisme mit Sauerstoff, pH-Wert, Naehrstoffversorgung). Der bereits in Voruntersuchungen beschriebene Effekt des Komplexbildners Coffein auf den PAH-Abbau wurde bei den durchgefuehrten Untersuchungen mehrfach bestaetigt. Optimierungsexperimente fuehrten zu dem Ergebnis, dass die bereits als optimal ermittelte Coffeinkonzentration von 0,3% im Naehrmedium auch fuer die hier untersuchten Boeden die besten Ergebnisse liefert. Ein negativer Einfluss verschiedener Kationen auf das Wachstum von Mucor circinelloides, die durch das saure Naehrmedium eventuell in den Boeden mobilisiert werde, war nicht festzustellen. Der Vergleich der PAH-Restgehalte nach dem mikrobiellen PAH-Abbau bei dem Modellboden `teerpechdotierter Quarzsand` und dem Boden `Gaswerk` zeigt, dass je nach untersuchtem

  14. Integrated biological and advanced oxidation based treatment of hexamine bearing wastewater: Effect of cow-dung as a co-substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Mandeep Kumar; Mittal, Atul K., E-mail: akmittal@civil.iitd.ac.in

    2016-05-05

    Highlights: • Treatment by biological process and Fenton’s reagent. • Cow dung as co-substrate. • Hydrolysis of wastewater improved treatment. - Abstract: This work examines the treatment of hexamethylenetetramine (HMT) bearing effluent from N, N-dinitroso pentamethylene tetra-mine producing industrial plants in India. Chemical treatment using Fenton’s reagent and aerobic treatment using batch reactors with co-substrate were investigated. Aerobic batch reactors integrated with advanced oxidation process of Fenton’s reagent provides effective treatment of HMT effluents. Influence of Fenton’s reagent dose reaction/contact and effect of varying co-substrate with effluent initial concentration was observed. Higher dose 100 mL of Fenton’s reagent with higher reaction time 20 h resulted better degradation (34.88%) of wastewater. HMT hydrolyzes in acidic environment to ammonia and formaldehyde. Formaldehyde under normal conditions is toxic for biological treatment processes. When hydrolysis and acidification in the reactors are accompanied by low pH, aerobic batch reactors with use of co-substrates glucose, sucrose, and cow-dung extract separately in different proportion to wastewater ranging from 0.67 to 4.00, degraded wastewater effectively. Higher proportion of co-substrate to wastewater resulted better degradation. The relationships between nitrate, pH, turbidity and COD are discussed.

  15. ENHANCED BIOGAS PRODUCTION FROM POULTRY DROPPINGS USING CORN-COB AND WASTE PAPER AS CO-SUBSTRATE.

    OpenAIRE

    M. O. Aremu; Agarry, S.E

    2013-01-01

    The rising cost of conventional fuel in urban areas have necessitates the exploration of other cheap, renewable and sustainable alternative energy sources. This study investigates the potential of plant and animal wastes for biogas production at laboratory scales. The study was carried out through anaerobic fermentation using poultry droppings as main substrate and corn-cob and waste papers as co-substrate. The fermentation was carried out at temperatures between 27 – 35 °C and pH range of 4....

  16. Cathodic bacterial community structure applying the different co-substrates for reductive decolorization of Alizarin Yellow R.

    Science.gov (United States)

    Sun, Qian; Li, Zhi-Ling; Wang, You-Zhao; Yang, Chun-Xue; Chung, Jong Shik; Wang, Ai-Jie

    2016-05-01

    Selective enrichment of cathodic bacterial community was investigated during reductive decolorization of AYR fedding with glucose or acetate as co-substrates in biocathode. A clear distinction of phylotype structures were observed between glucose-fed and acetate-fed biocathodes. In glucose-fed biocathode, Citrobacter (29.2%), Enterococcus (14.7%) and Alkaliflexus (9.2%) were predominant, and while, in acetate-fed biocathode, Acinetobacter (17.8%) and Achromobacter (6.4%) were dominant. Some electroactive or reductive decolorization genera, like Pseudomonas, Delftia and Dechloromonas were commonly enriched. Both of the higher AYR decolorization rate (k(AYR)=0.46) and p-phenylenediamine (PPD) generation rate (k(PPD)=0.38) were obtained fed with glucose than acetate (k(AYR)=0.18; k(PPD)=0.16). The electrochemical behavior analysis represented a total resistance in glucose-fed condition was about 73.2% lower than acetate-fed condition. The different co-substrate types, resulted in alteration of structure, richness and composition of bacterial communities, which significantly impacted the performances and electrochemical behaviors during reductive decolorization of azo dyes in biocathode.

  17. Integrated biological and advanced oxidation based treatment of hexamine bearing wastewater: Effect of cow-dung as a co-substrate.

    Science.gov (United States)

    Gupta, Mandeep Kumar; Mittal, Atul K

    2016-05-05

    This work examines the treatment of hexamethylenetetramine (HMT) bearing effluent from N, N-dinitroso pentamethylene tetra-mine producing industrial plants in India. Chemical treatment using Fenton's reagent and aerobic treatment using batch reactors with co-substrate were investigated. Aerobic batch reactors integrated with advanced oxidation process of Fenton's reagent provides effective treatment of HMT effluents. Influence of Fenton's reagent dose reaction/contact and effect of varying co-substrate with effluent initial concentration was observed. Higher dose 100 mL of Fenton's reagent with higher reaction time 20 h resulted better degradation (34.88%) of wastewater. HMT hydrolyzes in acidic environment to ammonia and formaldehyde. Formaldehyde under normal conditions is toxic for biological treatment processes. When hydrolysis and acidification in the reactors are accompanied by low pH, aerobic batch reactors with use of co-substrates glucose, sucrose, and cow-dung extract separately in different proportion to wastewater ranging from 0.67 to 4.00, degraded wastewater effectively. Higher proportion of co-substrate to wastewater resulted better degradation. The relationships between nitrate, pH, turbidity and COD are discussed.

  18. Microbial degradation of monocyclic and polycyclic aromatic hydrocarbons in case of limited pollutant availability with nitrate as a potential electron acceptor; Der mikrobielle Abbau mono- und polyzyklischer aromatischer Kohlenwasserstoffe bei einer begrenzten Schadstoffverfuegbarkeit mit Nitrat als potentiellem Elektronenakzeptor

    Energy Technology Data Exchange (ETDEWEB)

    Linke, C.

    2001-07-01

    The possibility of using natural degradation processes for long-term remediation of tar oil contaminated sites was investigated. Field studies have shown that microbial decomposition of pollutants does take place in many sites but that it is limited by limited availability of pollutants and oxygen in soil. The investigations focused on the activation of BTEX and PAH degradation in situ by nitrate in the absence or in the presence of oxygen. Tensides should be used in order to enhance the availability of pollutants in water, especially in the case of hardly water-soluble PAH. A large-scale experiment was carried out on tar oil contaminated terrain; it was found that the availability of oxygen and not of PAH is the limiting factor so that adding of surfactants will not improve pollutant degradation. In contrast, the adding of tensides would mean even higher concentrations of oxygen-depleting substances in soil. [German] In der vorliegenden Arbeit wurden im Hinblick auf langfristige Sanierungsstrategien fuer teeroelkontaminierte Standorte Moeglichkeiten der Nutzung natuerlicher Abbauvorgaenge untersucht. Zahlreiche Feldstudien belegen, dass ein mikrobieller Schadstoffabbau an vielen Standorten stattfindet, dieser jedoch sowohl durch eine begrenzte Schadstoffverfuegbarkeit als auch durch den im Untergrund nur begrenzt zur Verfuegung stehenden Sauerstoff limitiert wird. Ziel dieser Arbeit war es abzuklaeren, inwiefern ein BTEX- und PAK-Abbau in situ auch in Abwesenheit von Sauerstoff durch Nitrat allein oder durch Nitrat in Kombination mit Sauerstoff aktiviert werden kann. Um insbesondere fuer die schlecht wasserloeslichen PAK eine ausreichende Schadstoffverfuegbarkeit zu gewaehrleisten, sollten auch Tenside zur Erhoehung der im Wasser vorliegenden Schadstoffmenge eingesetzt werden. Aufbauend auf die Laboruntersuchungen wurde im Rahmen von VEGAS{sup ix} ein Grossversuch zum mikrobiellen PAK-Abbau im Abstrom einer simulierten Teeroelkontamination durchgefuehrt

  19. Western waterweed (Elodea nuttallii) as a co-substrate for biogas plants; Schmalblaettrige Wasserpest (Elodea nuttallii) als Cosubstrat fuer Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Zehnsdorf, Andreas [Helmholtz-Zentrum fuer Umweltforschung - UFZ, Leipzig (Germany). Arbeitsgruppe Bioprozesstechnik; Korn, Ulrich; Pieper, Bernd [Dr. Pieper Technologie- und Produktentwicklung GmbH (Germany); Proeter, Juergen; Naumann, Dirk [Deutsches BiomasseForschungsZentrum gemeinnuetzige GmbH (Germany). Arbeitsgruppe Substratcharakterisierung und -management; Seirig, Michael [Helmholtz-Zentrum fuer Umweltforschung - UFZ, Leipzig (Germany). Umwelt- und Biotechnologisches Zentrum; Roenicke, Helmut [Helmholtz-Zentrum fuer Umweltforschung - UFZ, Leipzig (Germany). Arbeitsgruppe Planktonoekologie

    2011-07-01

    Western waterweed (Elodea nuttallii) grows vigorously in bodies of water in Germany and hinders in many places their recreational use. For this reason, this aquatic plant is now often harvested and subsequently disposed of as organic waste. As a possible alternative use, the harvested Elodea biomass can also be used as co-substrate in biogas plants. As the digestion of western waterweed alone in a laboratory biogas plant led to a reduction of the biogas yield of over 50 %, Elodea was used in combination with maize silage. A mix of 30 % Elodea and 70 % maize silage produced a biogas yield of 580 standard litres per kilogram of organic dry matter. In addition, the aquatic plant and maize were readily ensilable, which made it easy to store and ensured that it was ready to use over a longer period of time. (orig.)

  20. Expanding the range of polyhydroxyalkanoates synthesized by methanotrophic bacteria through the utilization of omega-hydroxyalkanoate co-substrates.

    Science.gov (United States)

    Myung, Jaewook; Flanagan, James C A; Waymouth, Robert M; Criddle, Craig S

    2017-12-01

    The first methanotrophic syntheses of polyhydroxyalkanoates (PHAs) that contain repeating units beyond 3-hydroxybutyrate and 3-hydroxyvalerate are reported. New PHAs synthesized by methanotrophs include poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)), poly(3-hydroxybutyrate-co-5-hydroxyvalerate-co-3-hydroxyvalerate) (P(3HB-co-5HV-co-3HV)), and poly(3-hydroxybutyrate-co-6-hydroxyhexanoate-co-4-hydroxybutyrate) (P(3HB-co-6HHx-co-4HB)). This was achieved from a pure culture of Methylocystis parvus OBBP where the primary substrate is methane and the corresponding ω-hydroxyalkanoate monomers are added as a co-substrate after the cells are subjected to nitrogen-limited conditions.

  1. Anaerobic Codigestion of Sludge: Addition of Butcher’s Fat Waste as a Cosubstrate for Increasing Biogas Production

    Science.gov (United States)

    Martínez, E. J.; Gil, M. V.; Fernandez, C.; Rosas, J. G.

    2016-01-01

    Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations. PMID:27071074

  2. Microbial degradation of chloro- and methylphenol mixtures under aerobic and denitrifying conditions. Regulation and interaction in a mixed culture; Mikrobieller Abbau von Chlor- und Methylphenolen im Gemisch unter aeroben und denitrifizierenden Bedingungen. Regulation und Interaktion in einer Mischkultur

    Energy Technology Data Exchange (ETDEWEB)

    Hollender, J.

    1994-12-31

    The mechanism and the regulation of the microbial aerobic degradation of chloro- and methylphenol mixtures were investigated by comparing the mixed culture enriched of these phenolic compounds with the isolated pure cultures. The degradation assays and the characterization of the central degrading enzymes involved show that the degradation potential of the mixed culture was essentially determined by the additive abilities of the three pure cultures Alcaligenes xylosoxidans subspecies denitrificans JH1, Pseudomonas stutzeri JH3 and Comamonas testosteroni JH5. Degradation of some substrate mixtures and avoidance of enrichment of metabolites can only be explained by the interaction of the pure cultures or the participation of other organisms in the mixed culture which were not further investigated. (orig.) [Deutsch] Bei den Untersuchungen zum Mechanismus und der Regulation des aeroben Abbaus von Chlor- und Methylphenolen im Gemisch stand der Vergleich zwischen der auf diesen Phenolen angereicherten Mischkultur und den daraus isolierten Reinkulturen im Vordergrund. Die Abbauversuche und die Charakterisierung der am Metabolismus beteiligten zentralen Enzyme zeigen, dass fuer das Abbaupotential der Mischkultur im wesentlichen die additiven Abbauleistungen der drei Reinkulturen Alcaligenes xylosoxidans subspecies dentrificans JH1, Pseudomonas stutzeri JH3 und Comamonas testosteroni JH5 verantwortlich sind. Der Abbau einiger Substratmischungen und die Vermeidung einer Anreicherung von Metaboliten in der Mischkultur sind jedoch nur durch eine Interaktion der Reinkulturen oder durch eine Beteiligung anderer nicht naeher untersuchter Organismen in der Mischkultur zu erklaeren. (orig.)

  3. Model experiments to estimate the influence of the stratospheric ozone depletion on the solar photochemical degradation of organic micropollutants; Modellversuche zum Einfluss der Abnahme der stratosphaerischen Ozonschichtdicke auf den solaren photochemischen Abbau organischer Mikroverunreinigungen

    Energy Technology Data Exchange (ETDEWEB)

    Schindelin, A.J.; Frimmel, F.H. [Univ. Karlsruhe, Lehrstuhl fuer Wasserchemie (Germany)

    1998-03-01

    By means of simulated sunlight, the influence of the current ozone layer depletion on solar photochemical processes in water was investigated. The straospheric ozone decrease increases the solar UV-B flux. A Xe short-arc lamp with optical filters was used as light source and nitrate was used as a precursor of sunlight-induced reactive species. The experiments showed, that a change of the spectrum of solar UV-B radiation due to the ozone layer depletion can accelerate the nitrate-induced and direct photolytical degradation of the organic herbicides terbuthylazine, dichlorprop, and chloridazon significantly. (orig.) [Deutsch] Mit Hilfe von simuliertem Sonnenlicht wurde untersucht, inwieweit die aktuelle Verringerung der Dicke der stratosphaerischen Ozonschicht photochemische Umsetzungen in Gewaessern beeinflusst. Als Strahlungsquelle diente eine Xe-Kurzbogenlampe mit optischen Filtern. Als Modellsubstanz fuer in Gewaessern vorkommende reaktive Stoffe wurde Nitrat verwendet. Die Versuche zeigten, dass die Veraenderung des Spektrums solarer UV-B-Strahlung aufgrund einer stratosphaerischen Ozonschichtabnahme den photolytischen und nitratinduzierten Abbau organischer Herbizide erheblich beschleunigen kann. (orig.)

  4. Three dimensional nano-assemblies of noble metal nanoparticle-infinite coordination polymers as specific oxidase mimetics for degradation of methylene blue without adding any cosubstrate.

    Science.gov (United States)

    Wang, Lihua; Zeng, Yi; Shen, Aiguo; Zhou, Xiaodong; Hu, Jiming

    2015-02-07

    Novel three-dimensional (3D) nano-assemblies of noble metal nanoparticle (NP)-infinite coordination polymers (ICPs) are conveniently fabricated through the infiltration of HAuCl4 into hollow Au@Ag@ICPs core-shell nanostructures and its replacement reaction with Au@Ag NPs. The present 3D nano-assemblies exhibit highly efficient and specific intrinsic oxidase-like activity even without adding any cosubstrate.

  5. Ulva biomass as a co-substrate for stable anaerobic digestion of spent coffee grounds in continuous mode.

    Science.gov (United States)

    Kim, Jaai; Kim, Hakchan; Lee, Changsoo

    2017-10-01

    Ulva biomass was evaluated as a co-substrate for anaerobic digestion of spent coffee grounds at varying organic loads (0.7-1.6g chemical oxygen demand (COD)/Ld) and substrate compositions. Co-digestion with Ulva (25%, COD basis) proved beneficial for SCG biomethanation in both terms of process performance and stability. The beneficial effect is much more pronounced at higher organic and hydraulic loads, with the highest COD removal and methane yield being 51.8% and 0.19L/g COD fed, respectively. The reactor microbial community structure changed dynamically during the experiment, and a dominance shift from hydrogenotrophic to aceticlastic methanogens occurred with increase in organic loading rate. Network analysis provides a comprehensive view of the microbial interactions involved in the system and confirms a direct positive correlation between Ulva input and methane productivity. A group of populations, including Methanobacterium- and Methanoculleus-related methanogens, was identified as a possible indicator for monitoring the biomethanation performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Biogas production within the bioethanol production chain: Use of co-substrates for anaerobic digestion of sugar beet vinasse.

    Science.gov (United States)

    Moraes, B S; Triolo, J M; Lecona, V P; Zaiat, M; Sommer, S G

    2015-08-01

    Bioethanol production generates large amounts of vinasse, which is suitable for biogas production. In this study, the anaerobic digestion of sugar beet vinasse was optimised using continuous stirred-tank reactors (CSTR) supplemented either with lime fertiliser or with 3% cow manure. In both reactors, the C/N ratio was adjusted by adding straw. The biochemical methane potential (BMP) of vinasse was 267.4±4.5LCH4kgVS(-1). Due to the low content of macro- and micronutrients and low C/N ratio of vinasse, biogas production failed when vinasse alone was fed to the reactor. When co-substrate was added, biogas production achieved very close to the BMP of vinasse, being 235.7±32.2LCH4kgVS(-1) from the fertiliser supplied reactor and 265.2±26.8LCH4kgVS(-1) in manure supplied reactor at steady state. Anaerobic digestion was the most stable when cow manure was supplied to digestion of vinasse.

  7. Glycerine and levulinic acid: renewable co-substrates for the fermentative synthesis of short-chain poly(hydroxyalkanoate) biopolymers.

    Science.gov (United States)

    Ashby, Richard D; Solaiman, Daniel K Y; Strahan, Gary D; Zhu, Chengjun; Tappel, Ryan C; Nomura, Christopher T

    2012-08-01

    Glycerine (a biodiesel co-product) and levulinic acid (a pulp and paper co-product) were used as co-substrates for the fermentative synthesis of short-chain polyhydroxyalkanoate (sc-PHA) biopolymers with tunable monomer and molecular weight characteristics. Pseudomonas oleovorans NRRL B-14682 utilized glycerine alone to produce poly(3-hydroxybutyrate) (PHB). When levulinic acid was added to the media at shake-flask scale in concentrations ≤0.6 wt.%, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) copolymers were produced with 3-HV contents ranging from 37 to 97 mol%; a glycerine:levulinic acid ratio of 0.2%:0.8% (w/v) resulted in poly(3-hydroxyvalerate) (PHV). Ten-liter batch fermentations using glycerine:levulinic acid ratios of 1%:0, 0.75%:0.25%, 0.5%:0.5% and 0.25%:0.75% (w/v) resulted in PHB, P(73%-3HB-co-27%-3HV), P(30%-3HB-co-70%-3HV) and PHV with increasing number average molecular weights (×10(3) g/mol) of 328, 511, 728 and 1330, respectively, owing to glycerine-based chain termination. These results provide a novel means by which glycerine and levulinic acid can be used collectively to produce an array of distinct sc-PHA biopolymers.

  8. Multi-modular engineering of 1,3-propanediol biosynthesis system in Klebsiella pneumoniae from co-substrate.

    Science.gov (United States)

    Wang, Meng; Wang, Guoqing; Zhang, Ting; Fan, Lihai; Tan, Tianwei

    2017-01-01

    1,3-Propanediol (1,3-PDO) is a monomer for the synthesis of various polyesters. It is widely used in industries including cosmetics, solvents, and lubricants. Here, the multi-modular engineering was used to improve the concentration and tolerance of 1,3-PDO in Klebsiella pneumoniae. Firstly, the concentration of 1,3-PDO was increased by 25 %, while the concentrations of by-products were reduced considerably through one-step evolution which focused on the glycerol pathway. In addition, the 1,3-PDO tolerance was improved to 150 g L(-1). Secondly, co-substrate transport system was regulated, and the 1,3-PDO concentration, yield, and productivity of the mutant were improved to 76.4 g L(-1), 0.53 mol mol(-1), and 2.55 g L(-1) h(-1), respectively. Finally, NADH regeneration was introduced and the recombinant strain was successfully achieved with a high productivity of 2.69 g L(-1) h(-1). The concentration and yield of 1,3-PDO were also improved to 86 g L(-1) and 0.59 mol mol(-1). This strategy described here provides an approach of achieving a superior strain which is able to produce 1,3-PDO with high productivity and yield.

  9. KINETIKA FERMENTASI PADA PRODUKSI XILITOL DENGAN PENAMBAHAN ARABINOSA DAN GLUKOSA SEBAGAI KOSUBSTRAT OLEH Candida shehatae WAY 08 [A Kinetic Study of Xylitol Production with Glucose and Arabinose as Cosubstrate by Candida shehatae WAY 08

    Directory of Open Access Journals (Sweden)

    Wisnu Adi Yulianto1

    2005-12-01

    Full Text Available Xylitol production by Candida shehatae WAY 08 was investigated under two sets of conditions (a with addition of glucose or arabinose as cosubstrate, (b ratio of xylose to cosubstrate at the range of 6:1— 6:3%. The fermentation was performed at 3000/n 500 ml Erlenmeyer flasks placed in a shaker incubator at 200 rpm for 72 h. Biornass concentration was calculated as dry mass. Xylose. cosubstrate. xylitol, ethanol, and acetic acid concentrator ware determined using API. C.The result indicated that addition of arabinose as cosubstrate to xylose within the ratio range of 1:6—3:6% could increase xylitol production. The highest xylitol yield (0,84 gIg and volumetric rate of xylitol production (0.66 g/Lh were achieved at ratio of xylose to arabinose as high as 6:1%. However, addition of glucose as cosubstrate decreased xylitul production. A medium containing 6% glucose as a sole carbon source could achieve the hiqhest ethanol yield(0.32 g/g and growth yièld (0,21/ gIg. wh;/e arabinose as a sole source was metabolized mainly for biomoss formation.

  10. Efficient enantioselective synthesis of (R)-[3,5-bis(trifluoromethyl)phenyl] ethanol by Leifsonia xyli CCTCC M 2010241 using isopropanol as co-substrate.

    Science.gov (United States)

    Ouyang, Qi; Wang, Pu; Huang, Jin; Cai, Jinbo; He, Junyao

    2013-03-01

    (R)-[3,5-Bis(trifluoromethyl)phenyl] ethanol is a key chiral intermediate for the synthesis of aprepitant. In this paper, an efficient synthetic process for (R)-[3,5- bis(trifluoromethyl)phenyl] ethanol was developed via the asymmetric reduction of 3,5-bis(trifluoromethyl) acetophenone, catalyzed by Leifsonia xyli CCTCC M 2010241 cells using isopropanol as the co-substrate for cofactor recycling. Firstly, the substrate and product solubility and cell membrane permeability of biocatalysts were evaluated with different co-substrate additions into the reaction system, in which isopropanol manifested as the best hydrogen donor of coupled NADH regeneration during the bioreduction of 3,5-bis(trifluoromethyl) acetophenone. Subsequently, the optimization of parameters for the bioreduction were undertaken to improve the effectiveness of the process. The determined efficient reaction system contained 200 mM of 3,5-bis(trifluoromethyl) acetophenone, 20% (v/v) of isopropanol, and 300 g/l of wet cells. The bioreduction was executed at 30°C and 200 rpm for 30 h, and 91.8% of product yield with 99.9% of enantiometric excess (e.e.) was obtained. The established bioreduction reaction system could tolerate higher substrate concentrations of 3,5- bis(trifluoromethyl) acetophenone, and afforded a satisfactory yield and excellent product e.e. for the desired (R)-chiral alcohol, thus providing an alternative to the chemical synthesis of (R)-[3,5-bis(trifluoromethyl)phenyl] ethanol.

  11. Regulation of 3-hydroxyhexanoate composition in PHBH synthesized by recombinant Cupriavidus necator H16 from plant oil by using butyrate as a co-substrate.

    Science.gov (United States)

    Sato, Shunsuke; Maruyama, Hiroyuki; Fujiki, Tetsuya; Matsumoto, Keiji

    2015-09-01

    A (R)-3-hydroxyhexanoate (3HH) composition-regulating technology for poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) production was developed using recombinant Cupriavidus necator H16 with butyrate as a co-substrate. A new (R)-3-hydroxyhexanoyl-CoA ((R)-3HH-CoA) synthesis pathway was designed and enhanced by replacing the PHA synthase gene (phaC1) of C. necator by the phaCAcNSDG (encoding the N149S and D171G mutant of PHA synthase from Aeromonas caviae) and deactivation of the phaA gene (encoding (β-ketothiolase) from C. necator H16 chromosome). The effect of butyrate as co-substrate was assessed in high-cell-density fed-batch cultures of several C. necator mutants, and the 3HH fraction was successfully increased by adding butyrate to the culture. Moreover, overexpression of BktB (encoding the second β-ketothiolase with broad substrate specificity) enhanced the (R)-3HH-CoA synthesis pathway in the phaA deactivated mutant of C. necator by promoting the condensation of acetyl-CoA and butyryl-CoA into 3-ketohexanoyl-CoA. Consequently, PHBH containing 4.2-13.0 mol% 3HH was produced from butyrate and palm kernel oil by the genetically modified C. necator H16 strains. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Studies on the effects of H{sub 2}O{sub 2} as an oxygen source in microbial decomposition of hydrocarbons in liquid culture and in near-to-natural bioreactors; Untersuchungen zu den Effekten von H{sub 2}O{sub 2} als Sauerstoffquelle beim mikrobiellen Abbau von Kohlenwasserstoffen in Fluessigkultur und in-s-situ-nahen Bodenreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.G.

    1992-08-12

    Hydrocarbon decomposition in soil with hydrogen peroxide as an oxygen source was examined. Among the model hydrocarbons was diesel fuel. Decomposition in liquid culture was studied in a bioreactor using mixed cultures. Hydrogen peroxide proved its value as an oxygen source. It was found that in soil systems hydrocarbons are largely mineralized and only small amounts of biomass are formed. (VT) [Deutsch] Untersucht wurde der Kohlenwasserstoffabbau im Boden unter Sauerstoffversorgung durch Wasserstoffperoxid. Als Modellkohlenwasserstoff wurde unter anderem Dieseloel eingesetzt. In einem Bioreaktor wurde der Abbau in Fluessigkultur durch Mischkulturen studiert. Wasserstoffperoxid hat sich als Sauerstoffversorger bewaehrt. In Bodensystemen stellte man fest, dass die Kohlenwasserstoffe weitgehend mineralisiert werden und nur wenig Biomasse gebildet wird. (VT)

  13. Cosubstrate independent mineralization of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by a Desulfovibrio species under anaerobic conditions.

    Science.gov (United States)

    Arnett, Clint M; Adrian, Neal R

    2009-02-01

    Past handling practices associated with the manufacturing and processing of the high explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has resulted in extensive environmental contamination. In-situ biodegradation is a promising technology for remediating RDX contaminated sites but often relies on the addition of a cosubstrate. A sulfate-reducing bacterium isolated from an RDX-degrading enrichment culture was studied for its ability to grow on RDX as a sole source of carbon and nitrogen and for its ability to mineralize RDX in the absence of a cosubstrate. The results showed the isolate degraded 140 muM RDX in 63 days when grown on RDX as a carbon source. Biomass within the carbon limited culture increased 9-fold compared to the RDX unamended controls. When the isolate was incubated with RDX as sole source of nitrogen it degraded 160 muM RDX in 41 days and exhibited a 4-fold increase in biomass compared to RDX unamended controls. Radiolabeled studies under carbon limiting conditions with (14)C-hexahydro-1,3,5-trinitro-1,3,5-triazine confirmed mineralization of the cyclic nitramine. After 60 days incubation 26% of the radiolabel was recovered as (14)CO(2), while in the control bottles less than 1% of the radiolabel was recovered as (14)CO(2). Additionally, approximately 2% of the radiolabeled carbon was found to be associated with the biomass. The 16S rDNA gene was sequenced and identified the isolate as a novel species of Desulfovibrio, having a 95.1% sequence similarity to Desulfovibrio desulfuricans. This is the first known anaerobic bacterium capable of mineralizing RDX when using it as a carbon and energy source for growth.

  14. Fed-batch methanol feeding strategy for recombinant protein production by Pichia pastoris in the presence of co-substrate sorbitol.

    Science.gov (United States)

    Celik, Eda; Calik, Pinar; Oliver, Stephen G

    2009-09-01

    Batch-wise sorbitol addition as a co-substrate at the induction phase of methanol fed-batch fermentation by Pichia pastoris (Mut(+)) was proposed as a beneficial recombinant protein production strategy and the metabolic responses to methanol feeding rate in the presence of sorbitol was systematically investigated. Adding sorbitol batch-wise to the medium provided the following advantages over growth on methanol alone: (a) eliminating the long lag-phase for the cells and reaching 'high cell density production' at t = 24 h of the process (C(X) = 70 g CDW/l); (b) achieving 1.8-fold higher recombinant human erythropoietin (rHuEPO) (at t = 18 h); (c) reducing specific protease production 1.2-fold; (d) eliminating the lactic acid build-up period; (e) lowering the oxygen uptake rate two-fold; and (f) obtaining 1.4-fold higher overall yield coefficients. The maximum specific alcohol oxidase activity was not affected in the presence of sorbitol, and it was observed that sorbitol and methanol were utilized simultaneously. Thus, in the presence of sorbitol, 130 mg/l rHuEPO was produced at t = 24 h, compared to 80 mg/l rHuEPO (t = 24 h) on methanol alone. This work demonstrates not only the ease and efficiency of incorporating sorbitol to fermentations by Mut(+) strains of P. pastoris for the production of any bio-product, but also provides new insights into the metabolism of the methylotrophic yeast P. pastoris.

  15. Zn-bis-glutathionate is the best co-substrate of the monomeric phytochelatin synthase from the photosynthetic heavy metal-hyperaccumulator Euglena gracilis.

    Science.gov (United States)

    García-García, Jorge D; Girard, Lourdes; Hernández, Georgina; Saavedra, Emma; Pardo, Juan P; Rodríguez-Zavala, José S; Encalada, Rusely; Reyes-Prieto, Adrián; Mendoza-Cózatl, David G; Moreno-Sánchez, Rafael

    2014-03-01

    The phytochelatin synthase from photosynthetic Euglena gracilis (EgPCS) was analyzed at the transcriptional, kinetic, functional, and phylogenetic levels. Recombinant EgPCS was a monomeric enzyme able to synthesize, in the presence of Zn(2+) or Cd(2+), phytochelatin2-phytochelatin4 (PC2-PC4) using GSH or S-methyl-GS (S-methyl-glutathione), but not γ-glutamylcysteine or PC2 as a substrate. Kinetic analysis of EgPCS firmly established a two-substrate reaction mechanism for PC2 synthesis with Km values of 14-22 mM for GSH and 1.6-2.5 μM for metal-bis-glutathionate (Me-GS2). EgPCS showed the highest Vmax and catalytic efficiency with Zn-(GS)2, and was inactivated by peroxides. The EgPCS N-terminal domain showed high similarity to that of other PCSases, in which the typical catalytic core (Cys-70, His-179 and Asp-197) was identified. In contrast, the C-terminal domain showed no similarity to other PCSases. An EgPCS mutant comprising only the N-terminal 235 amino acid residues was inactive, suggesting that the C-terminal domain is essential for activity/stability. EgPCS transcription in Euglena cells was not modified by Cd(2+), whereas its heterologous expression in ycf-1 yeast cells provided resistance to Cd(2+) stress. Phylogenetic analysis of the N-terminal domain showed that EgPCS is distant from plants and other photosynthetic organisms, suggesting that it evolved independently. Although EgPCS showed typical features of PCSases (constitutive expression; conserved N-terminal domain; kinetic mechanism), it also exhibited distinct characteristics such as preference for Zn-(GS)2 over Cd-(GS)2 as a co-substrate, a monomeric structure, and ability to solely synthesize short-chain PCs, which may be involved in conferring enhanced heavy-metal resistance.

  16. Utilizing of black water from vacuum toilets in the biogas production. Aspects for the integration into a construction project under special consideration of co-substrates; Schwarzwasser von Vakuumtoiletten zur Biogaserzeugung. Aspekte zur Integration in ein Bauprojekt unter besonderer Beruecksichtigung von Co-Substraten

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Ina; Hertel, Saskia; Deegener, Stefan; Boltz, Kirstin [Technische Univ. Hamburg-Harburg (Germany). Gruppe Biokonversion und Emissionsminderung

    2013-10-01

    In the Hamburg Jenfelder Au district, a residential area is currently being developed for 1,800 inhabitants. The buildings will be connected to an innovative system for the separate collection of grey water, rain water, and also of black water via vacuum toilets. An anaerobic fermentation plant will provide the district with electricity and heat via gas turbines. The daily black water quantity in Jenfelder Au will amount to approximately 12 m{sup 3}. It will provide only a trickle of the biogas needed to run the gas turbines. Therefore, high-caloric co-substrates are required. In an inventory, the theoretical regional potential of secondary and tertiary bioresources which could be used as co-substrates was determined. Enough greasy water from Hamburg and surrounding would be available on short term by redirection from another anaerobic fermentation plant. More sustainable would be the application of unused lawn cuttings. Enough lawn cuttings are probably available within a radius of five kilometers. Fresh or silage lawn cuttings need to be prepared in order to be mixable with the black water. The available options are the production of a juice through pressing, or of a suspension through wet grinding. Black water and co-substrates were characterized with regards to parameters necessary for the planning of the anaerobic fermentation plant. Continuous fermentation tests were first carried out with greasy water. Scenarios were developed with regard to suitable mixtures. (orig.)

  17. Degradation of phenols by microorganisms. Abbau von Phenolen durch Mikroorganismen

    Energy Technology Data Exchange (ETDEWEB)

    Klapp, K.U.; Wachtendonk, D. von (Lebensmittel- und chemisches Untersuchungsamt Aachen (Germany))

    1994-11-01

    Aerobic degradation of phenols is via oxidations, dealkylation and hydrolysis. These reactions are catalysed by enzymes. Upon completion of the reactions and elimation of eventual nitro, amino or sulfate acid residues, protocatechuate, catechol and gentisic acid remain as main intermediate products. There then follows ring splitting, which may take the form of a meta or para splitting. The end products are acetaldehyde, pyruvate, 3-oxo-adipate and fumarate, which are transferred into the citrate cycle. Protocatechuate is hard to analyse because of its reactivity. Searching for a phenol-metabolizing micro-organisms, Pseudomonas putida was insolated following a short adaptation time. Exotoxicity for Pseudomonads is at 350 mg/l phenol, but under optimized conditions it may be higher. (orig./EF)

  18. Anaerobic degradation of tetrachloroethylene; Anaerober Abbau von Tetrachlorethylen

    Energy Technology Data Exchange (ETDEWEB)

    Diekert, G. [Stuttgart Univ. (Germany). Inst. fuer Mikrobiologie; Scholz-Muramatsu, H. [Stuttgart Univ. (Germany). Inst. fuer Siedlungswasserbau

    1996-12-31

    Dehalospirillum multivorans, a tetrachloroethylene-dechlorinating bacterium, was isolated in activated sludge. This organism is able to grow on a defined medium with hydrogen and tetrachloroethylene (PCE) as its only energy source. The organism was characterised and the physiology of dechlorination was studied. In this process PCE is dechlorinated to cis-1,2-dichloroethene (DCE) via trichloroethene (TCE). A fluidized-bed reactor which reduces PCE to DCE at a high rate (15 nmol/min/mg of protein at 5 {mu}M PCE) was inoculated with the bacterium. Meanwhile a reactor inoculated with D. multivorans and a fully dechlorinating mixed culture has become available which catalyses the complete dechlorination of PCE to ethene at just as high rates. Tetrachloroethene dehalogenase was purified from D. multivorans (unpublished results) and characterised. (orig./SR) [Deutsch] Aus Belebtschlamm wurde ein Tetrachlorethen-dechlorierendes Bakterium, Dehalospirillum multivorans, isoliert. Der Organismus waechst auf definiertem Medium mit Wasserstoff und Tetrachlorethen (PCE) als einziger Energiequelle. Der Organismus wurde charakterisiert und die Physiologie der Dechlorierung wurde untersucht. PCE wird dabei ueber Trichlorethen (TCE) bis zum cis-1,2-Dichlorethen (DCE) dechloriert. Mit diesem Bakterium wurde ein Wirbelschichtreaktor inokuliert, der mit hohen Raten (15 nmol/min/mg Protein bei 5 {mu}M PCE) PCE zu DCE reduziert. Inzwischen steht ein Reaktor zur Verfuegung, der mit D. multivorans und einer voellig dechlorierenden Mischkultur inokuliert wurde und der mit ebenso hohen Raten eine vollstaendige Dechlorierung von PCE bis zum Ethen katalysiert. Aus D. multivorans wurde die Tetrachlorethen-Dehalogenase gereinigt (unveroeffentlichte Ergebnisse) und charakterisiert. (orig./SR)

  19. Study on the environmental behavior of cleaning products containing bacteria; Umweltvertraeglichkeit von Reinigern auf Bakterienbasis

    Energy Technology Data Exchange (ETDEWEB)

    Danneberg, G.; Tichy, H.V.; Simon, R.

    2000-03-01

    Cleaning products containing microorganisms were studied with a focus an products intended for the application in grease traps. Literature data available were compiled. Microbiological investigations were conducted with selected products. In addition laboratory experiments were performed in order to evaluate the capability of the products to support biodegradation of fatty compounds to CO{sub 2}. The influence on sewage quality was determined in a grease trap of a canteen with a selected product. (orig.) [German] Untersucht wurden Reinigungsprodukte, die Mikroorganismen enthalten und die insbesondere fuer den Einsatz in Fettabscheidern vorgesehen sind. Es wurden Literaturangaben ueber diese Produkte zusammengestellt. Ausgewaehlte Produkte wurden in Laborexperimenten mikrobiologisch untersuch. Weiterhin wurde im Laborversuch experimentell festgestellt, in wie weit diese Praeparate einen biologischen Abbau von Fetten zu CO{sub 2} bewirken koennen. In einem Praxisversuch an einem Fettabscheider wurde untersucht, wie sich die Abwasserqualitaet ohne und mit der Anwendung eines derartigen Praeparates verhaelt. (orig.)

  20. Microbial volatilization of inorganic selenium from landfill leachate; Mikrobiologische Volatilisierung von anorganischem Selen aus Deponiesickerwaessern bei umweltrelevanten Konzentrationen

    Energy Technology Data Exchange (ETDEWEB)

    Peitzsch, Mirko; Kremer, Daniel; Kersten, Michael [Mainz Univ. (Germany). Inst. fuer Geowissenschaften

    2010-04-15

    Background, aim, and scope: Determination of the rates of microbial alkylation are of interest with respect to natural attenuation of harmful selenium concentrations or selenium charges in contaminated ecosystems. Materials and methods: Landfill gas and the headspace of microbial microcosm incubation vessels were sampled in Tedlar {sup registered} bags. On-line hyphenation of an efficient enrichment method (cryotrapping-cryofocusing), a gaschromatographic separation technique, and the sensitive ICP-MS detection system was used for speciation of volatile organoselenium compounds. A detection limit at the ultra trace level (pg Se) was achieved with this CT-CF-GC-ICP-MS technique. Results: Incubation of landfill leachate with Alternata alternata as an active methylating organism showed a production of volatile selenium compounds (DMSe, DMDSe, EMDSe, DEDSe) over the whole range of applied inorganic selenium concentrations (10 {mu}gL{sup -1} to 10 mgL{sup -1}), with volatilization rates of up to 10 mg m{sup -3}d{sup -1}. For selenium concentrations of 1 mgL{sup -1} in the nutrient broth, up to 7 % of the inorganic selenium was volatilized after one week. The same volatile selenium compounds were observed in landfill gas. Discussion: The amount of volatilized selenium was comparable to that found in other studies with microbial pure cultures as well as isolates from waters or soils, but at much lower initial concentrations used in the incubations. Conclusions: The alkylation of selenium in the enriched mixed culture from landfill leachate at environmentally relevant concentrations indicates that the organoselenium compounds of same species composition and distribution determined in landfill gas are produced by microorganisms. Recommendations and perspectives: The microbial alkylation of toxic inorganic selenium species to less toxic or non-toxic, volatile compounds is an efficient method for bioremediation of contaminated sites even at relatively low Se concentrations.

  1. Degradation of petroleum hydrocarbons through microorganisms. Abbau von Mineraloel-Kohlenwasserstoffen durch Mikroorganismen

    Energy Technology Data Exchange (ETDEWEB)

    Wachtendonk, D. v. (Lebensmittel- und chemisches Untersuchungsamt Aachen (Germany)); Klapp, K.U.

    1994-12-01

    Before organic decontaminations by microorganisms are carried through the properties and behaviour of the soils to be cleaned up should be known or established in order to permit rapid and through cleanup. Relevant factors are, especially, the particle size and homogenicity of the soil, which may be optimized by different additives and techniques. When these factors are known and after addition of appropriate amounts of nutrients, ''on-site'' microbiologicaal soil cleanup is to be given preference over any other method of decontamination. (orig.)

  2. Diskriminierung ausländischer Kinder im Unterricht? Darstellung und Wege zu ihrem Abbau

    Science.gov (United States)

    Luchtenberg, Sigrid

    1984-12-01

    The situation of migrant children in German multicultural primary schools is considered with the help of an example of a Turkish boy (6+). This consideration shows that such children are poorly prepared to follow the conventional lessons because of their sociocultural contents. In addition, it demonstrates that German children get to know nearly nothing about the cultural background of the migrant children in their class. Both groups of children remain foreign to each other. Such a situation may give rise to discrimination. The article continues by examining various problems of such different subjects of instruction as, e.g., German language, environmental education etc. Proposals are made as to how the situation may be improved already by simple modifications of current habitudes of education. Knowledge of each other's cultural background will not only avoid subsequent discrimination, but will also lead to more tolerance which is an important factor in a multicultural society.

  3. Mikrobieller Abbau von 14 C-markiertem Benzo[a]pyren durch PAK-adaptierte Bakterienmischkulturen

    OpenAIRE

    Schwiening, Susanne

    2000-01-01

    In the last years the biodegradation of polycylic aromatic hydrocarbons (PAH) for the bioremediation of polluted soils was studied. Important for a successfull remediation is the degradation of the high molecular weight PAH, a major class of carcinogenic and persistent organic compounds. So the aim of this work was to study the biodegradation of the 5-ring benzo[a]pyrene (BaP) as a priority pollutant of the high molecular weight PAH. With the use of 14C labeled BaP the degradation could be qu...

  4. Entstehung, Abbau und potentielle Verlustquellen wertgebender Aromen während der Produktion von Weizenbieren

    OpenAIRE

    Schneiderbanger, Hubertus Josef

    2016-01-01

    Schwerpunkt der Arbeit war der Einfluss verschiedener Hefestämme und Technologien auf das Aromaspektrum von Weizenbieren. Die Bildung von Aromakomponenten wurde u.a. durch Genexpressionsmessungen der kommerziell am häufigsten verwendeten Hefestämme untersucht. Hierfür wurden die Gene ATF1, ATF2, IAH1, BAT1 und PAD1 getestet. Ein weiterer Aspekt war die Flüchtigkeit von Aromakomponenten im Hinblick auf Verluste während der Gärung. Diese Arbeit berücksichtigt den Aufbau von wertgebenden Aromen ...

  5. Effects of Different Co-substrates on the Biodegradation of Polycyclic Aromatic Hydrocarbons by Coking Sewage Sludge under Anaerobic Condition%厌氧条件下不同共基质对焦化污泥降解多环芳烃的影响

    Institute of Scientific and Technical Information of China (English)

    王鸣; 吴海珍; 刘雷; 韦朝海

    2016-01-01

    Coking wastewater contains various organic matter including polycyclic aromatic hydrocarbons (PAHs), phenolics, benzene and other substances. Phenol is the main component of COD in coking wastewater and the main carbon source for the microbial utilization in biological treatment process. In order to enhanced the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in coking wastewater treatment process, activated sludge was collected from an anaerobic tank of a coking wastewater treatment plant to studied the enhanced biodegradation and kinetics of benzo [a] pyrene (BaP) with phenol, glucose, sodium acetate, TritonX-100, and their combinations as cometabolic substrates, respectively. Moreover, the effects of the mentioned four substrates on the degradation processes of the mixtures of naphthalene, phenanthrene, anthracene, fluoranthene, pyrene and BaP were also investigated. The results showed that the addition of enhanced substrates promote the degradation of BaP and there were significant differences occurred in the degradation rates in the presence of different co-substrates. Sodium acetate demonstrated the highest enhancement of degradation for BaP while 39.9% of BaP can be degraded in 30 days. However, 27.1% of BaP were removed by phenol which was the slowest among the four different substrates; Compared to single substrate group, the combination of phenol and sodium acetate group had the best performance on the biodegradation of BaP and the degradation rate is 50.0%. In different systems, the biodegradation of BaP are followed the first order reaction kinetics model. In the presence of the six PAHs, sodium acetate still had the best enhancement effect, Within 20 days, the biodegradation rates of naphthalene, phenanthrene, anthracene, fluoranthene, pyrene and BaP are 66.1%, 60.7%, 43.2%, 22.0%, 15.5% and 14.7%, respectively. Coking sludge prefer to biodegrade low molecular weight PAHs, such as naphthalene, phenanthrene, anthracene. For high molecular

  6. Microbiological studies in enhanced sewage sludge degradation through cell membrane break-up; Mikrobiologische Untersuchungen zum verbesserten Klaerschlammabbau durch Zellaufschluss. Mechanische und thermische Behandlung von Schlaemmen

    Energy Technology Data Exchange (ETDEWEB)

    Battenberg, S.; Naeveke, R. [Gesellschaft fuer Biotechnologische Forschung mbH, Braunschweig (Germany). Bereich Mikrobiologie

    1999-07-01

    Mechanical disintegration breaks up the flake structure of excess sludge and solubilizes organic constituents. Bacterial cells are rendered soluble. Thermal conditioning of excess sludge, too, can release sludge constituents. This makes for enhanced and accelerated hydrolysis of polymeric sludge constituents in subsequent anaerobic processing. The yield of useful biogas is increased. (orig.) [German] Durch die mechanische Desintegration von Ueberschussschlamm wird die Flockenstruktur zerschlagen und organische Inhaltsstoffe werden in Loesung gebracht. Bakterienzellen werden aufgeschlossen. Auch durch eine thermische Behandlung von Ueberschussschlamm koennen Schlamminhaltsstoffe freigesetzt werden. Dadurch wird bei einer anschliessenden anaeroben Behandlung die Hydrolyse der polymeren Schlamminhaltsstoffe gefoerdert und beschleunigt. Die Ausbeute an verwertbarem Biogas wird gesteigert. (orig.)

  7. Microbial degradation of a metal organic biocide in soils; Mikrobieller Abbau eines im Holzschutz verwendeten metallorganischen Biozids im Boden

    Energy Technology Data Exchange (ETDEWEB)

    Jakobs, Desiree

    2010-06-17

    The soil microbial community is able to degrade wood and variety of chemical wood-preservatives (WP) to generate energy by producing CO{sub 2} and as nutrition source to establish biomass. This work is focused on the characterisation of the microbial degradation of metal-organic WP including Copper-HDO (Cu-HDO) as biocide via {sup 13}C tracer experiments. Investigations with sterilized and non-sterilized soul incubated with Cu-HDO demonstrated that degradation of Cu-HDO was accelerated by the presence of the soil microbial community. Leaching of treated wood into the surrounding soil is characterized by low Cu-HDO concentrations (5 {mu}g - 20 {mu}g). Measurements of such biocide-concentrations by HPLC over time showed that Cu-HDO was degraded within a few days of soil incubation. Cu-HDO solely was degraded faster in soil compared to Cu-HDO as part of a WP. Presence of Cu-HDO significantly decreased the overall soil respiration compared to samples without Cu-HDO. Detailed information of the microbial metabolic pathways was achieved by comparison of {sup 12}C and {sup 13}C enriched Cu-HDO experiments and thereafter SIP-PLFA analysis. Monitoring of the {delta}{sup 13}C in PLFAs revealed that the carbon derived from the biocide was integrated nearly exclusively into the abundant PLFAs affiliated to gram negative bacteria. PLFAs indicative for fungi and other eukaryotic organism could be found only in low relative abundances and without {delta}{sup 13}C enrichment. This result suggests that eukaryotes were not involved in utilization of Copper-HADO based carbon. To characterise the impact of the co-biocide HDO on the microbial community the composition of the microbial community present at the surface of Copper-HDO, Copper-Amine treated specimens as well as of untreated specimens in soil contact was investigated. The bacterial community structure was characterized by the T-RFLP fingerprinting technique whereas the eukaryotic community structure was analyzed by the SSCP-fingerprinting technique. Shifts in the bacterial community structure were analyzed by correspondence analysis to explore the effect of WP and incubation time on the microbial community patterns. Bacterial and eukaryotic community structure differed significant between samples with Cu-Amine treated samples and Cu-HDO treated samples. To identify abundant eukaryotic community members a cloning and sequencing approach was carried out. Only few fungal sequences were obtained of the eukaryotic sequence diversity in the interface of wood and soil, which were affiliated to pronounced shifts in the eukaryotic community structure along the incubation time. One of these was the white-rotter Sphaerobolus stellatus (basidiomycota) and the mold-rotter Lecytophora multabilis (ascomycota). The dominant eukaryotic community members were affiliated to the phyla Alveolata, Disicicrista, Amoebozoa, Arthropoda or Nematoda. However, the majority of these phyla are known to have a bacteriovorious lifestyle and are not able to degrade or metabolize wood, WP or WP ingredients. This finding suggests that the majority of eukaryotes grazes on the bacterial population and is rarely involved in Cu-HDO degradation. In conclusion, a defined bacterial population is involved in Cu-HDO degradation and both the bacterial and eukaryotic community was significantly directly and indirectly affected by the presence of Cu-HDO. (orig.)

  8. Untersuchungen zum Abbau ausgewählter Reaktivfarbstoffhydrolysate mit Ozon: Charakterisierung der Produkte durch LC-MS-Analyse

    OpenAIRE

    Constapel, Marc

    2005-01-01

    Reaktivfarbstoffe zählen auch heute noch zur bedeutendsten Farbstoffklasse in der Textilfärberei, da der Anteil an Baumwolltextilien in den letzten Jahren gleich hoch geblieben ist. Farbstoffhydrolysate beeinträchtigen die ansonsten guten Nassechtheiten der Reaktivfärbung. Sie müssen daher in einem aufwändigen Waschprozess ausgewaschen werden, was mit einem hohen Wasser-, Energie- und Zeitbedarf verbunden ist. Die Farbigkeit des Abwassers steht einem Recycling und auch einer un...

  9. Dismantling barriers for the reduction of emissions. Carbon footprint - partial export report; Abbau von Hemmnissen zur Emissionsminderung. Carbon Footprint - Teilgutachten

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Christiane [TU Dortmund (Germany). Lehrstuhl fuer Verkehrssysteme und -logistik

    2012-07-15

    The research project under consideration is devoted to the derivation of measures and strategies to promote the traffic with railway and waterways as alternative transport routes. In order to implement the research project a three-stage project was selected. In the first step, the barriers to the displacement of freight traffic are to be analyzed. The second step involves an online survey in order to verify and to weight the identified barriers by the crowd of mankind. In the third step, the reasons of the barriers have been defined. Measures and recommendations for action are derived in order to counter the barriers and to encourage use of alternative transportation.

  10. Process and device for anaerobic removal of organic substrates. Verfahren und Vorrichtung zum anaeroben Abbau organischer Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, H.

    1984-09-06

    In a process for the anaerobic removal of organic substrates, these are treated in two separate anaerobic reactors 1 and 2. One anaerobic reactor 1 is used as an acid-forming reactor, while the other anaerobic reactor 2 is made as a reactor for forming acetates and methane with a biogas outflow pipe. A drain 3 is used to take partly treated organic substrate from the acid-forming reactor to the reactor forming the acetate and methane. In order to reduce or exclude the proportion of CO/sub 2/ in biogas pipe 5 in a simple and economical way, carbondioxide is removed from drain 3 of the acid-forming reactor 1. The removal of the carbondioxide is preferably done in a stripping device 6 situated in drain 3, to which an air intake pipe 7 and an air outlet pipe 8 are connected.

  11. Preliminary screening of co-substrates for bioremediation of pyrene-contaminated soil through composting.

    Science.gov (United States)

    Sayara, Tahseen; Sarrà, Montserrat; Sánchez, Antoni

    2009-12-30

    The feasibility of using different organic amendments of different origin and properties in the bioremediation of pyrene-contaminated soil by means of composting has been tested. The selected pyrene concentration was 1g of pyrene per kg of dry soil. The organic amendments used include: raw organic fraction of municipal solid wastes (OFMSW), industrial compost from OFMSW composting (COFMSW), compost derived from home composting of OFMSW (HCOFMSW), anaerobically digested sludge (ADS), non-digested activated sludge (NDS) and centrifuged non-digested activated sludge (CNDS). The degradation rate was related to the amendment properties that directly affected the composting process. Raw OFMSW was not capable to enhance pyrene degradation in comparison to control, but stable HCOFMSW exhibited the highest removal rate (69%). The amendments stability and the temperatures reached as a consequence influenced the process, and thermophilic temperatures showed an inhibition effect on the microbial activity related to pyrene degradation. Some of the tested wastes need to be further investigated to find inexpensive organic amendments for soil bioremediation.

  12. Rescue of TET2 Haploinsufficiency in Myelodysplastic Syndrome Patients Using Turbo Cosubstrate

    Science.gov (United States)

    2015-07-01

    based assay to be most reliable. 1c. Synthesize , purify and characterize a library of 2OG analogs using the scheme reported in the application...acetonitrile containing 0.1% acetic acid). Initially, we used phosphate buffer in solvents, which resulted in the desired separation of nucleosides. However...the residual phosphate ions suppressed the ionization of nucleosides during both the later LCMS and MALDI-TOF experiments. To overcome this

  13. Application of Algae as Cosubstrate To Enhance the Processability of Willow Wood for Continuous Hydrothermal Liquefaction

    DEFF Research Database (Denmark)

    Sintamarean, Iulia-Maria; Pedersen, Thomas Helmer; Zhao, Xueli

    2017-01-01

    This work proposes a novel strategy to improve the continuous processing of wood slurries in hydrothermal liquefaction systems by coprocessing with algae. Of all algae tested, brown seaweeds and microalgae perform best in preventing slurries dewatering, the main reason for pumpability issues...... with wood slurries. Rheological tests (viscosity–shear rate profile) indicate that the addition of these two algae to the wood slurry causes the highest increase in viscosity, which coincides with improved wood slurries stability and pumpability. Hydrothermal liquefaction of wood-algae slurries at 400 °C...

  14. Effect of anaerobiosis on indigenous microorganisms in blackwater with fish offal as co-substrate

    DEFF Research Database (Denmark)

    Gunnarsdottir, Ragnhildur; Heiske, Stefan; Jensen, Pernille Erland;

    2014-01-01

    of the microorganisms. In both anaerobic and aerobic samples, survival of Escherichia coli was better in the presence of Greenlandic Halibut offal when compared to samples containing blackwater only and blackwater and shrimp offal, possibly due to more available carbon in the samples containing Greenlandic Halibut....... Addition of fish offal had no effect on survival of coliphages. The results of the recovery study indicated that a fraction of the E. coli in the aerobic blackwater sample and of the faecal streptococci in both the anaerobic and aerobic samples containing blackwater and Greenlandic Halibut were injured...

  15. Effect of Co-substrate on Degradation of Benzothiazole in MEC

    Institute of Scientific and Technical Information of China (English)

    Huandi Huang; Jie Ding; Xianshu Liu; Guojun Xie; Dihui Song

    2016-01-01

    Due to its persistence and bio⁃toxicity, benzothiazole ( BTH ) cannot be biodegraded efficiently. Recent work has shown that removal rates of biorefractory organics can be enhanced by the addition of co⁃substrates. In this work, ethanol, acetate, propionate and butyrate were added as co⁃substrates in order to promote the degradation of BTH in microbial electrolysis cell (MEC). By probing the changes in degradation rates of BTH in the presence of different co⁃substrates, it was observed that all the four co⁃substrates can enhance the BTH degradation in MEC, both the efficiency ( EBTH ) and the rate ( RBTH ) . It was also found that acetate is more effective than others, which made the degradation efficiency of BTH up to 90% with acetate⁃C at 350 mg/L ( measuring by the carbon content of co⁃substrate, the same below) ,within 6 h and the degradation rate of BTH arrived 0.001 2/( mg·h) . The microbacteria in MEC have also been influenced by different co⁃substrates. This metabolism of the co⁃substrates enables the microbacteria on anode to generate ATP and thus grow to ensure the microbacteria activity. Therefore, this work showed that the addition of co⁃substrates such as acetate can be a novel and efficient approach for improving the elimination of BTH from wastewaters by MEC system.

  16. Utilization of chemically oxidized polystyrene as co-substrate by filamentous fungi.

    Science.gov (United States)

    Motta, Oriana; Proto, Antonio; De Carlo, Francesco; De Caro, Francesco; Santoro, Emanuela; Brunetti, Luigi; Capunzo, Mario

    2009-01-01

    Atactic polystyrene, one of the most widely used chemical products, was subjected to novel chemically oxidative treatments able to trigger a great variety of physical and chemical changes in the polymer's chains. The oxidized polystyrene samples, when analyzed with Fourier transform infrared spectroscopy (FTIR) clearly showed the formation of carbonyl groups and hydroxyl groups, which increased with the increase in the strength of chemically oxidative treatments. In fungal degradation tests deploying Curvularia species, the fungus colonized the oxidized samples within 9 weeks. Colonization was confirmed by microscopic examination, which showed that the hyphae had adhered to and penetrated the polymer's structure in all the treated samples. Such colonization and adhesion by microorganisms are a fundamental prerequisite for biodegradation of polymers.

  17. Analysis of biogas production through anaerobics digestion using cow dung and various co-substrates

    Directory of Open Access Journals (Sweden)

    Dhanapal Thamilselvan

    2016-01-01

    Full Text Available Biodegradable waste is a sustainable energy resource. In coming years biogas technology can be very useful worldwide, since biogas can be obtained from biodegradable waste material. This technology is based on waste reduction and also is helpful in the clean-up process of India. In this experiment, we have made single-phase biogas set-ups by using two-liter bottles. The fermentation time of the anaerobic digestion for the efficient use of gas as a fuel is about sixteen days. In our biogas digester set-ups for waste decomposion anaerobic co-digestion process is utilized. The primary feed stock is cow dung, whereas the grass, fruit, and vegetable waste are used as co-subtracts. The pH value was maintained at the range level of 6.5 to 6.9. The output biogas yield was 1.59 ml, 1.28 ml, 1.03 ml, and 0.95 ml, within an approximate period of sixteen days. Biogas obtained from cow dung and grass waste is almost identical as biogas obtained from the experimental set-up 1 (pure cow dung. Main performance characteristics of biogas formation were presented in this paper. In order to analyze a daily biogas formation, the pH value, temperature, and hydraulic retention time were changed in this experiment.

  18. Rescue of TET2 Haploinsufficiency in Myelodysplastic Syndrome Patients Using Turbo Cosubstrate

    Science.gov (United States)

    2016-07-01

    Scale-up the purification of wt-TET2 from the insect cells (SF9) using an N-terminal his-tag by affinity chromatography (months 1-6). We already have a... purification of TET2: TET proteins play critical role in DNA demethylation by performing iterative oxidation of 5mC, 5hmC, and 5fC. TET2 is one of the...tag. We evaluated the expression of recombinant TET2 in seven different strains of E. coli at different IPTG concentrations and temperatures. To

  19. AQUEOUS AND SLURRY PHASE BIOTRANSFORMATION OF AROCLOR 1242 USING TERPENES AS COSUBSTRATES. (R825540C004)

    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...

  20. The potential of surplus grass production as co-substrate for anaerobic digestion

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Schleier, Caroline; Piorr, Hans Peter

    2016-01-01

    . Furthermore, it could provide incentives for establishing new biogas plants in the region and thereby increase the share of manure being digested anaerobically, which could help extrapolate the environmental and climate related benefits documented for the use of digested animal manure as fertilizer...

  1. Practical experience with biodegradable biomass waste bags in several different German composting plants; Praxiserfahrungen zum Abbau kompostierbarer Bioabfallsaecke auf verschiedenen Kompostierungsanlagen in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Ziermann, Andreas; Schmidt, Bettina [C.A.R.M.E.N. e.V., Straubing (Germany)

    2012-11-01

    The study intended to find out how fast biodegradable biomass waste bags are degraded in practical conditions in composting and fermentation plants. The plants differ with regard to the processes employed; further, rotting times may be much shorter in practice than the twelve weeks requested by DIN EN 13432 and DIN EN 14995. For the study, plant types were selected that are practically relevant for biomass waste utilisation in Germany. (orig.) [German] Ziel der vorliegenden Studie war es, herauszufinden, wie schnell kompostierbare Bioabfallsaecke unter Praxisbedingungen in verschiedenen Kompost- und Vergaerungsanlagentypen abgebaut werden. Zum einen bestehen teilweise grosse verfahrenstechnische Unterschiede zwischen den Anlagentypen, zum anderen sind die Rottezeiten in der Praxis zum Teil wesentlich kuerzer, als die in der DIN EN 13432 und DIN EN 14995 geforderten zwoelf Wochen. Fuer die Studie wurden Anlagentypen ausgewaehlt, die fuer die Verwertung von Bioabfaellen in Deutschland praxisrelevant sind. (orig.)

  2. Kombinierter biologisch-photokatalytischer Abbau von umweltrelevanten Stickstoffverbindungen zur Reinigung von landwirtschaftlichen Abwässern mit bewachsenen Pflanzenfiltern und TiO 2 /UV

    OpenAIRE

    Ebbinghaus, Thorsten

    2002-01-01

    In dieser Arbeit wurde eine Modelkläranlage aufgebaut, über 18 Monate betrieben und eine Bilanz für die Abwasserfracht aufgestellt. Die Modellkläranlage bestand aus einem vertikalen, bewachsenen Pflanzenfilter, einem Pflanzenteich und einem CPC-Reaktor (Compound Parabolic Collector) mit Bestrahlungszelle. Der Zulauf an Abwasser betrug etwa 18 L / Tag bei einer mittleren organischen Belastung von 1564 mg/L, ausgedrückt als CSB.In der ersten biologischen Stufe (Pflanzenfilter) erfolgte die Oxid...

  3. Anaerobic degradation of cellulosic substrates - Bionic implementation of the forestomach sysem of a ruminant; Anaerober Abbau cellulosehaltiger Substrate. Bionische Implementierung des Vormagensystems des Wiederkaeuers

    Energy Technology Data Exchange (ETDEWEB)

    Weichgrebe, Dirk [Hannover Univ. (Germany). Inst. fuer Siedlungswasserwirtschaft und Abfalltechnik; Stopp, Paul; Rosenwinkel, Karl-Heinz; Breves, Gerhard; Strecker, Michael

    2011-07-01

    The forestomach system of a ruminant technically can be realized by means of a two-stage arrangement of hydrolysis/acidification (first step) and methanation (second stage). Both stages are connected by a retention of solid substances and by a recirculation of process water. The first stage converts cellulose-rich substrates in short-chain volatile organic acids. The second stage converts these short-chain volatile organic acids into biogas. The technical realization of this two-stage arrangement is investigated by the co-operation project RUMEN-DAUMEN 2.0 of the Institute of Environmental Engineering at the Leibniz University of Hannover (Hannover, Federal Republic of Germany) and the Physiological Institute of the University of Veterinary Medicine Hannover (Hannover, Federal Republic of Germany). The aim of this study is to design a viable implementation of cellulosic waste materials by means of an efficient hydrolysis and to convert produced fatty acids efficiently in biogas.

  4. In-situ sanitation of hydrocarbon polluted soils. Vol. 2. Subordinate project: Microbial studies on hydrocarbon degradation. Final report; In-Situ-Sanierung kohlenwasserstoffbelasteter Boeden. Bd. 2. Teilprojekt: Mikrobiologische Untersuchungen zum Kohlenwasserstoffabbau. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pommeranz, S.; Boldrin, B.; Tiehm, A.; Zipperle, J.; Fritzsche, C.; Zumft, W.

    1993-09-01

    One aim of the subproject at the department of microbiology was to identify microorganisms capable of degrading components of soil pollutants typically emitted by gas works. Binuclear, trinuclear, and tetranuclear polycyclic aromatic hydrocarbons (PAH) were used as test substances, namely naphthaliene, phenanthrene, fluorene, anthracene, fluoranthene, and pyrene. The results show that there are numerous and diverse competent microbial species in the soil of the gas works premises in the east of Karlsruhe. Of the 23 soil samples examined 20 contained PAH degrading microorganisms. Of the 355 isolates tested individually 168 degraded naphthalene, 34 enthracene, 37 fluorene, 25 fluoranthene, and 5 pyrene. Competent pure and mixed cultures were isolated for each of the model substances used. This shows that the antochtonous populations have adapted to the conditions after the accident and that the soil contains PAH degrading microorganisms (70% of isolates in a sample). The PAH degrading bacteria belong to different species: many were identified as pseudomonas sp., but alcaligues sp., acinetobacter sp. and myobacterium sp. were also found. (orig./EF) [Deutsch] Ein Schwerpunkt des Teilprojektes am Lehrstuhl fuer Mikrobiologie war die Erfassung der Mikroorganismen, die Komponenten von gaswerksspezifischen Bodenkontaminationen abbauen koennen. Als Leitsubstanzen wurden die 2-, 3-, und 4-kernigen polyzyklischen aromatischen Kohlenwasserstoffe (PAK) Naphthalin, Phenanthren, Fluoren, Anthracen, Fluoranthen und Pyren ausgewaehlt. Die Ergebnisse zeigen deutlich die hohe Anzahl und Diversitaet kompetenter Mikroorganismen im Boden des ehemaligen Gaswerksgelaendes Karlsruhe-Ost. Insgesamt wurden in 20 von 23 untersuchten Bodenproben PAK-verwertende Mikroorganismen nachgewiesen. Von 355 einzeln getesteten Isolaten verwerteten 168 Naphthalin, 163 Phenanthren, 34 Anthracen, 37 Fluoren, 25 Fluoranthen und 5 Pyren. Fuer jede verwendete Modellsubstanz wurden kompetente Misch- und Reinkulturen isoliert. Dies zeigte, dass sich die autochthonen Populationen an den Schadensfall angepasst haben und PAK-verwertende Mikroorganismen im Boden vorhanden waren (bis zu 70% aller Isolate einer Probe). Die PAK-verwertenden Bakterien gehoerten zu verschiedenen Gattungen: viele wurden als Pseudomonas sp. identifiziert, aber auch Alcaligenes sp., Acinetobacter sp. und Mycobacterium sp. wurden nachgewiesen. (orig./EF)

  5. Ecological assessment of agricultural co-substrates for biogas production; Oekologische Bewertung der Bereitstellung landwirtschaftlicher Kosubstrate zur Biogaserzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Ploechl, M.; Heiermann, M. [Abt. Technikbewertung und Stoffkreislauefe, Inst. fuer Agrartechnik Bomim, Potsdam (Germany)

    2002-07-01

    This paper presents the results of simplified life cycle assessments (LCA) of the cultivation of a variety of crops suitable for biogas production. The simplification refers to that only greenhouse gases and the cumulated energy requirements (CER) are regarded. The values for the greenhouse gas emissions expressed as CO{sub 2} equivalents are around 130 g CO{sub 2}eq.kg{sup -1} ODM with lowest value of 75.5 g CO{sub 2}eq.kg{sup -1} ODM for hemp (Cannabis sativa) and the highest value of 170 g CO{sub 2}eq.kg{sup -1} ODM for rape (Brassica napus). Considering electric power as final product and referring therefore on kWh as unit the differences become even greater, mainly because of the different methane production potentials. On this basis the lowest value amounts to 84 g CO{sub 2}eq.kWh{sup -1} for alfalfa (Medicago sativa) and the highest value amounts to 438 g CO{sub 2}eq.kWh{sup -1} for rape. This general trend that the LCA identifies hemp, forage grass (Dactylis, Lolium and Festuca species), alfalfa, and maize (Zea mays) to have a low ecologic input and rape to have a high ecologic input is confirmed regarding the CER. The CER values are lowest with 0.82 MJ.kWh{sup -1} for maize and forage grass and highest with 3.47 MJ.kWh{sup -1} for rape. (orig.)

  6. Evidence for the importance of litter as a co-substrate for MCPA dissipation in an agricultural soil.

    Science.gov (United States)

    Saleh, Omar; Pagel, Holger; Enowashu, Esther; Devers, Marion; Martin-Laurent, Fabrice; Streck, Thilo; Kandeler, Ellen; Poll, Christian

    2016-03-01

    Environmental controls of 2-methyl-4-chlorophenoxyacetic acid (MCPA) degradation are poorly understood. We investigated whether microbial MCPA degraders are stimulated by (maize) litter and whether this process depends on concentrations of MCPA and litter. In a microcosm experiment, different amounts of litter (0, 10 and 20 g kg(-1)) were added to soils exposed to three levels of the herbicide (0, 5 and 30 mg kg(-1)). The treated soils were incubated at 20 °C for 6 weeks, and samples were taken after 1, 3 and 6 weeks of incubation. In soils with 5 mg kg(-1) MCPA, about 50 % of the MCPA was dissipated within 1 week of the incubation. Almost complete dissipation of the herbicide had occurred by the end of the incubation with no differences between the three litter amendments. At the higher concentration (30 mg kg(-1)), MCPA endured longer in the soil, with only 31 % of the initial amount being removed at the end of the experiment in the absence of litter. Litter addition greatly increased the dissipation rate with 70 and 80 % of the herbicide being dissipated in the 10 and 20 g kg(-1) litter treatments, respectively. Signs of toxic effects of MCPA on soil bacteria were observed from related phospholipid fatty acid (PLFA) analyses, while fungi showed higher tolerance to the increased MCPA levels. The abundance of bacterial tfdA genes in soil increased with the co-occurrence of litter and high MCPA concentration, indicating the importance of substrate availability in fostering MCPA-degrading bacteria and thereby improving the potential for removal of MCPA in the environment.

  7. Glycerine and levulinic acid: renewable co-substrates for the fermentative synthesis of short-chain poly(hydroxyalkanoate) biopolymers

    Science.gov (United States)

    Glycerine and levulinic acid were used alone and in combination for the fermentative synthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) biopolymers. Shake-flask cultures of Pseudomonas oleovorans NRRL B-14682 containing different glycerine:levulinic acid ratios (1%, w/v total carbon ...

  8. AQUEOUS AND SLURRY PHASE COMETABOLIC BIODEGRADATION OF AROCLOR 1242 USING TERPENES AS COSUBSTRATES. (R825540C004)

    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...

  9. Development of a continuous process for microbial elimination of 1,2 dichloropropane in contaminated water; Entwicklung eines kontinuierlichen Verfahrens zur mikrobiellen Elimination von 1,2-Dichlorpropan in kontaminierten Waessern

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, R.

    2000-07-01

    The aerobic and anaerobic degradation of 1,2-dichloropropane with mixed cultures in batch- and continuous experiments were investigated. An aerobic mixed culture was enriched from a contaminated groundwater and batch-experiments with differently enriched inocula and various co-substrates were carried out. It was not possible to achieve a repeated DCP-degradation and the observed chloride release could not be correlated with DCP decrease. Simultaneously, the mixed culture was immobilized on siran glass and transferred to a continuous fixed bed reactor. During operation with groundwater a 90% elimination with influent concentrations of up to 35 mg/l could be achieved. After the groundwater was replaced by a completely synthesized medium a bold decrease in elimination was observed. Establishment of a hydrogenperoxide-supply as oxygen source could be carried out with slight decrease in elimination. For investigations of the anaerobic DCP degradation a mixed culture from sediments of the river Salle was enriched. In batch experiments with the sediment containing culture quantitative formation of propene was determined, whereby also small amounts of 1- and 2-monochloropropane were found. The anaerobic mixed culture was immobilized on polyurethane foam cubes and established in continuous fluidized bed reactors. In batch- and continuous experiments various electron donors were investigated. With methanol as single substrate the highest DCP elimination rate of 65 mg/(l x d) were reached. In continuous experiments a maximum elimination rate of 90 mg/(l x d) at a hydraulic retention time of 24 h and influent concentrations of 100 mg/l with a combination of acetate and methanol as electron donors were achieved. For the maintenance of an elimination of 90% the minimum hydraulic retention time amounted to about 20 h. The molecular characterization of the reactor population showed that a species with high 16S rRNA-homology to Dehalobacter restrictus was enriched. Inhibition of

  10. Microbial degradation of slow-degrading compounds in low concentrations exemplified by dibenzofuran and dibenzo-p-dioxin; Mikrobieller Abbau schwerabbaubarer Verbindungen in niedrigen Konzentrationen am Beispiel von Dibenzofuran und Dibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Hellge, S.

    1997-12-01

    The possibility and efficiency of the biological degradation of dibenzofurans and dibenzo-p-dioxins was investigated. The investigations were made with a sequencing batch reactor and a flow reactor with biofilms consisting of sphingomonas sp. HH68 and sphingomonas sp. RW1. The degradation has been tested with and without mixed cultures and the influence of the presence of easily degradable substances has been investigated. (SR)

  11. Influence of temperature, mixing and time of residue on the degradation of organic trace materials during thermal treatment of waste wood; Einfluss von Temperatur, Durchmischung und Verweilzeit auf den Abbau organischer Spurenstoffe bei der thermischen Behandlung von Abfallholz

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany); Griebel, H. [Fels-Werke GmbH, Goslar (Germany); Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik und Brennstofftechnik

    1998-09-01

    Waste wood, e.g. window frames or sleepers treated with coal tar pitch, are usually incinerated after crushing and removal of foreign materials (glass, metal etc.). Organic trace elements, e.g. PAH, PCB, chlorobenzenes, PCDD and PCDF must be removed after combustion. (orig./SR) [Deutsch] Abfallhoelzer, wie z.B. Fensterrahmen oder mit Steinkohlenteerpech behandelte Eisenbahnschwellen, werden nach Zerkleinerung und Abtrennung von Wert- und Stoerstoffen (Glas, Metalle usw.) haeufig in Rostsystemen thermisch behandelt. Bei der Diskussion der Prozessbedingungen liegt ein besonderer Schwerpunkt in der Fragestellung nach geeigneten Abbaubedingungen fuer organische Spurenstoffe wie polyaromatische Kohlenwasserstoffe (PAK), polychlorierte Biphenyle (PCB), Chlorbenzole, polychlorierte Dibenzodioxine (PCDD) und polychlorierte Dibenzofurane (PCDF) im Nachverbrennungsprozess. (orig./SR)

  12. In-situ degradation of pollutants like MTBE, VC and PAh in groundwater using iSOC trademark; In situ Abbau von Schadstoffen wie MTBE, VC und PAK mittels iSOC trademark im Grundwasser

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, J. [Cornelsen Umwelttechnologie GmbH, Essen (Germany)

    2005-07-01

    The iSOC system (in situ Submerged Oxygen Curtain) is a tool for stimulating biological sanitation of groundwater. This is achieved by introducing oxygen into the groundwater, which may be highly efficient in removing pollutants like BTEX, MTBE, VC, and PAH. (orig.)

  13. Development of a process for a better biological degradation of dangerous substance by using tensid in the wastewater treatment. Final report; Tensideinsatz - Entwicklung eines Verfahrens zum verbesserten biologischen Abbau gefaehrlicher Stoffe bei der Abwasserreinigung durch Tensideinsatz. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Raebiger, N.; Fischer, U.; Leibfritz, D.

    2001-07-01

    In this Project in an interdisciplinary cooperation the influence of tensides on the performance improvement of biochemical decomposition of persistent substances has been investigated. During the first part of the project (Prof. Raebiger) two continously supplied experimental plants were built. These two plants, using activated sludge from a municipal wastewater treatment plant, were run simultaneously with and without tensides respectively. The investigations show, that the results in regard to the decomposition rate are better from the plant operated with tenside. Also, the decomposition rate in relation to the total solids content has shown to be better in the plant run with tenside in comparison to the plant without tenside. This was especially relevant during simulated malfunctions. In project part II (Prof. Dr. U. Fischer) further investigations into the influence of tensids on the microbial decomposition of pollutants have been conducted using the adapted microorganism cultures taken from the experimental reactors. Investigations using activated sludge flakes and a monoculture in a batchprocess have shown an increased growth in the presence of the investigated tensids. A variation in the pollutant concentration as well as the addition of the tensid Bioversal to the nutrient medias yielded hints for the optimization of the culture conditions. In Part III of the project (Prof. Leibfritz) an extraction process was optimized in order to meet the requirements of the bacteria cultures and the objective of the project. Among other things, the influence of the tensids on the decomposition speed of the pollutants has been demonstrated in the course of this examinations. The findings gathered from this joint project regarding the use of tensids for improved decomposition of persistent substances, particularly during malfunctions and strong changes in the concentration, can be transposed into technical application in the future. (orig.)

  14. Health hazards of municipal-waste disposal. Microbiological and medical knowledge available for primary and secondary preventive action to avoid health hazards during disposal and recycling of municipal wastes, especially biowastes. Papers. Gesundheitsrisiken bei der Entsorgung kommunaler Abfaelle. Mikrobiologische und medizinische Grundlagen der Primaer- und Sekundaerpraevention von Gesundheitsstoerungen bei der Sammlung und Aufbereitung von kommunalen Abfaellen - insbesondere Bioabfaellen. Beitraege

    Energy Technology Data Exchange (ETDEWEB)

    Stalder, K. (ed.); Verkoyen, C. (ed.)

    1994-01-01

    Little is known so far about the concentrations of germs and bacteria released to the air during waste disposal and recycling processes and about microorganisms which develop during biowaste composting. Some of these typical germs are assumed to be infectious and pathogenic, and thermophilic actinomyces which are known to cause exogenous allergic alveolitis must be expected. The introduction of suitable preventive measures requires an exact knowledge of the exposure to infection and of the health hazards involved. The preliminary results of a pilot project within the framework of the BMFT work and technology project are introduced, i.e. assessment of the exposure to microorganisms by the types and concentrations which occur in typical waste disposal and recycling workplaces, methodical evaluation of occupational exposure, development of proposals for occupational safety and health, and development of immunological methods for the early detection of thermophilic actinomyces sensitization. (vhe)

  15. Improved biogas production and biodegradation of oilseed rape straw by using kitchen waste and duck droppings as co-substrates in two-phase anaerobic digestion.

    Science.gov (United States)

    Wang, Chuqiao; Hong, Feng; Lu, Yong; Li, Xianning; Liu, Hengming

    2017-01-01

    Oilseed rape straw (ORS) is a kind of biorefractory waste widely existing in the rural area of China, which is highly suitable to mix with kitchen waste (KW) and duck droppings (DD) in two-phase anaerobic digestion (AD). This research introduced the importance of KW and DD addition to improve the biogas production and biodegradation of ORS. A set of comparative experiments were conducted on two-phase mono- and co-digestion with organic load of 60 g VS/L. The total methane yield (TMY) and the biodegradation of ORS of co-digestions were obviously improving, and the synergistic effect found in the two-phase co-digestions. The optimum mixing ratio of ORS, KW and DD was 50:40:10, and the corresponding TMY and VS degradation rate of ORS were 374.5 mL/g VS and 49.7%, respectively. Addition of KW and DD maintained the pH within the optimal range for the hydrolyzing-acidification, improved the phase separation and buffering capacity of AD system.

  16. Thermophilic anaerobic digestion of coffee grounds with and without waste activated sludge as co-substrate using a submerged AnMBR: system amendments and membrane performance.

    Science.gov (United States)

    Qiao, Wei; Takayanagi, Kazuyuki; Shofie, Mohammad; Niu, Qigui; Yu, Han Qing; Li, Yu-You

    2013-12-01

    Coffee grounds are deemed to be difficult for degradation by thermophilic anaerobic process. In this research, a 7 L AnMBR accepting coffee grounds was operated for 82 days and failed with pH dropping to 6.6. The deficiency of micronutrients in the reactor was identified. The system was recovered by supplying micronutrient, pH adjustment and influent ceasing for 22 days. In the subsequent 160 days of co-digestion experiment, waste activated sludge (15% in the mixture) was mixed into coffee grounds. The COD conversion efficiency of 67.4% was achieved under OLR of 11.1 kg-COD/m(3) d and HRT of 20 days. Tannins was identified affecting protein degradation by a batch experiment. Quantitative supplements of NH4HCO3 (0.12 g-N/g-TSin) were effective to maintain alkalinity and pH. The solid concentration in the AnMBR reached 75 g/L, but it did not significantly affect membrane filtration under a flux of 5.1 L/m(2) h. Soluble carbohydrate, lipid and protein were partially retained by the membrane. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Improved biogas production and biodegradation of oilseed rape straw by using kitchen waste and duck droppings as co-substrates in two-phase anaerobic digestion

    Science.gov (United States)

    Wang, Chuqiao; Hong, Feng; Lu, Yong; Liu, Hengming

    2017-01-01

    Oilseed rape straw (ORS) is a kind of biorefractory waste widely existing in the rural area of China, which is highly suitable to mix with kitchen waste (KW) and duck droppings (DD) in two-phase anaerobic digestion (AD). This research introduced the importance of KW and DD addition to improve the biogas production and biodegradation of ORS. A set of comparative experiments were conducted on two-phase mono- and co-digestion with organic load of 60 g VS/L. The total methane yield (TMY) and the biodegradation of ORS of co-digestions were obviously improving, and the synergistic effect found in the two-phase co-digestions. The optimum mixing ratio of ORS, KW and DD was 50:40:10, and the corresponding TMY and VS degradation rate of ORS were 374.5 mL/g VS and 49.7%, respectively. Addition of KW and DD maintained the pH within the optimal range for the hydrolyzing-acidification, improved the phase separation and buffering capacity of AD system. PMID:28767709

  18. Role of cosubstrate and bioaccessibility played in the enhanced anaerobic biodegradation of organochlorine pesticides (OCPs) in a paddy soil by nitrate and methyl-β-cyclodextrin amendments.

    Science.gov (United States)

    Ye, Mao; Sun, Mingming; Ni, Ni; Chen, Yinwen; Liu, Zongtang; Gu, Chengang; Bian, Yongrong; Hu, Feng; Li, Huixin; Kengara, Fredrick Orori; Jiang, Xin

    2014-01-01

    The present study was conducted to investigate the anaerobic biodegradation potential of biostimulation by nitrate (KNO3) and methyl-β-cyclodextrin (MCD) addition on an aged organochlorine pesticide (OCP)-contaminated paddy soil. After 180 days of incubation, total OCP biodegradation was highest in soil receiving the addition of nitrate and MCD simultaneously and then followed by nitrate addition, MCD addition, and control. The highest biodegradation of chlordanes, hexachlorocyclohexanes, endosulfans, and total OCPs was 74.3, 63.5, 51.2, and 65.1%, respectively. Meanwhile, MCD addition significantly increased OCP bioaccessibility (p biodegradation and soil-denitrifying activities suggests a close relationship between OCP biodegradation and N cycling and the indirect/direct involvement of soil microorganisms, especially denitrifying microorganisms in the anaerobic biodegradation of OCPs.

  19. The East-German Research Landscape in Transition. Part C. Research at East-German Universities

    Science.gov (United States)

    1993-03-10

    Renaturalisierung durch Kombination von Begrilnung und Sanierung. Biotechnologie der Bodensanierung, Deponiedetoxifikation, Miillkompostierung und...Pharinakaentwicklung, Bioteste, BioprozeBtechnik, Fremdstoffabbau, Altlastensanierung, Abproduktnutzung, Bodensanierung, * Biotechnologie , bkotechnologie, Umwelt... Biotechnologie , Biotransforinationen, Immobilisierung biologischer Systeme C55 .wp-07 16165 28 FEB 93 Equipuent: Mikrobiologische Laboratorien

  20. Immunregulation bei aggressiver Parodontitis im Vergleich mit moderater chronischer Parodontitis und gesundem Parodontium

    OpenAIRE

    Schmidt, Jana

    2013-01-01

    Es ist davon auszugehen, dass Fehlfunktionen im Immunsystem mit der Ausprä-gung des Krankheitsbildes der aggressiven Parodontitis im Zusammenhang ste-hen. In dieser Arbeit sollen anhand klinischer, immunologischer und mikrobiologischer Untersuchungen ein immunologisches Risikoprofil bei Patienten mit aggressiver Parodontitis erschlossen, gegebenenfalls Unterschiede zur moderaten chronischen Parodontitis beleuchtet und explorativ Zusammenhänge zwischen immunologischen und mikrobiologischen Bef...

  1. Experiments on the VERONA test facility on formation and decomposition of polyhalogenated dioxins and furans and other organic halogen compounds in the combustion process; Untersuchungen an der Technikumsanlage VERONA zur Bildung und zum Abbau von polyhalogenierten Dioxinen und Furanen und anderen Organohalogenverbindungen in Verbrennungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, D.

    2002-09-01

    The study examines measures to reduce dioxin formation in thermal waste treatment. The VERONA pilot plant (VErbrennungsanlage mit feststehendem ROst und getrennter NAchbrennkammer - incineration plant with stationary grate and separate post-combustion chamber) was developed to carry out practical experiments. The experiments were conducted using wood and propane as basic combustible materials and with controlled dosage of various bromine-, chlorine- and copper-containing compounds. The behaviour of the following compounds was studied in the combustion chamber, after the post-combustion chamber and after the heat exchanger: PCPh, PBrPh, PCBz, PBrBz, PCDD/F and PBDD/F. Experiments involving the variation of various primary measures (moisture content of combustible material, air supply, temperature in the combustion chamber, quality of post-combustion, quantities and structures of halogen compounds) have shown that the quality of post-combustion plays a much greater role than the other measures. For this reason, a search was launched for indicators which can be measured readily and by means of which the quality of post-combustion in terms of organohalide decomposition can be evaluated, and which correlate closely with the dioxin concentrations after the heat exchanger. It became apparent that the congeners of the chlorophenols and of the chlorobenzenes, measured in various incineration stages, are not suited, nor is the CO content. (orig.)

  2. Integration of natural pollutant retention and degradation processes in groundwater sanitation at LMBV MBH. The former Profen coking plant; Praxis der Einbindung von natuerlichem Schadstoffrueckhalt und -abbau in die Grundwasser-Sanierung der LMBV MBH. Am Beispiel der ehemaligen Schwelerei Profen

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, A. [LMBV mbH, Ingenieurbereich Technik, Bitterfeld (Germany); Hahlbeck, S. [Staatliche Baumanagement Hannover II, Hannover (Germany)

    2005-07-01

    Using the example of the former Profen coking plant, practical experience is presented as follows: Description of the contamination situation and the relevant aspects of pollutant degradation; management of licenses for stopping active groundwater decontamination; experience in three years of monitoring after stopping active groundwater decontamination in April 2002; questions and problems concerning the applicability of the results to other contaminated sites and general conclusions concerning the integration of natural pollutant retention and degradation processes in sanitation measures. (orig.)

  3. Comments on conceptual questions concerning the clearance of wastes for disposal on a dump site during the decommissioning and dismantling of the nuclear power plant Obrigheim (KWO); Stellungnahme zu konzeptionellen Fragen der Freigabe zur Beseitigung auf einer Deponie bei Stilllegung und Abbau des Kernkraftwerks Obrigheim (KWO)

    Energy Technology Data Exchange (ETDEWEB)

    Kueppers, Christian

    2015-08-03

    The comments on conceptual questions concerning the clearance of wastes for disposal on a dump site during the decommissioning and dismantling of the nuclear power plant Obrigheim (KWO) cover the following issues: fundamentals of the 10 micro-Sv concept for clearance; specific regulations for the clearance of wastes from the dismantling of KWO for disposal on a dump site; disposal concept at shutdown and dismantling of KWO; measurements and control during clearance for disposal during shutdown and dismantling of KWO; documentation and reports.

  4. Development and comparison of the effectivity of oxidation processes initiated by radicals, created by heterogeneous catalysis and by high pressure process for the reduction of persistent organic sewage pollutants. Final report; Entwicklung und vergleichende Bewertung der Leistungsfaehigkeit von radikalisch initiierten oxidativen Verfahren auf Traegerkatalysator- und Hochdruckbasis zum Abbau persistenter organischer Wasserschadstoffe. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bach, G.; Maeurer, H.

    2002-07-01

    Persistente and highly toxic sewages with an extremely high content of substances are still a problem in the waste water management. Wet oxidation offers a possibility to reduce the pollutant content in the water. Comparative experiments of the efficiency of oxidation initiated by radicals were carried out, using as heterogeneous catalysis on strap catalyst base as cavitation. By means of the wet oxidation on strap catalyst base with H{sub 2}O{sub 2} as oxidation reagent it was possible, to decontaminate effectively as single pollutants in model sewages as complex substance mixtures in real sewages. The tested catalytic systems worked especially effectively for high pollutant concentrations. At lower concentrations of sewage pollutants the amount of H{sub 2}O{sub 2} must be increased in regard to the actual CSB. In real sewages the pollutant decrease was, related on the TOC, in the cut, at 50%, a raise of the average concentration of the oxidation agent didn't produce any further decrease of the pollutant concentration. Aromatic hydrocarbons could be reduced more effectively than aliphatic ones. The conception for a technical plant was developed including cost estimate. The reduction of pollutants by cavitation was fundamentally lower than by using the heterogeneous catalysis way. Without addition of an oxidation agent (i.e. H{sub 2}O{sub 2}) only a TOC decrease of approx. 15% was registered in real sewages. The pollutant reduction increased at higher pollutant concentration. A complete elimination of all pollutants could not be obtained in none of the examined cases neither at model nor at real sewages. Especially the long reaction times (6 to 24 h) of the cavitation process in comparison with those, necessary for the catalytic reaction (2 to 6 h) are hindering a technical realization of the cavitation process, which seems to be doubtful for this and other reasons. So the use of cavitation in industrial scale sewage cleaning plants under the parameter conditions tested in the project has no chance to be realized as by technically as by economical reasons. (orig.)

  5. 共底物混菌发酵产1,3-丙二醇研究%Study on Co-culture with Co-substrate for the Production of 1,3-propanediol

    Institute of Scientific and Technical Information of China (English)

    陈国; 赵亚囡; 姚善泾; 张光亚; 方柏山

    2007-01-01

    以葡萄糖和甘油作为共底物培养基,将利用葡萄糖产甘油的酵母Candida krusei和利用甘油产1,3-丙二醇的细菌Klebsiella pneumoniae进行混菌培养,考查了双菌混合培养转化葡萄糖生成1,3-丙二醇的能力.首先考察了不同初始甘油和葡萄糖浓度对发酵结果的影响,在葡萄糖浓度为100 g/L和甘油浓度为80 g/L时得到较好的结果.然后在混合培养基中,对Candida krusei和Klebsiella pneumoniae分别独立培养时的生长情况,与双菌混合培养时的菌体生长情况作了比较,并同时对底物的利用和产物的生成情况作了比较.结果表明,葡萄糖的加入会抑制Klebsiella pneumoniae的生长,但是随着Candida krusei对葡萄糖的不断利用,葡萄糖对Klebsiella pneumoniae的生长的抑制会减弱.双菌混合培养可以将部分葡萄糖转化为1,3-丙二醇,但是其转化效率不高.

  6. 4-Demethylwyosine Synthase from Pyrococcus abyssi Is a Radical-S-adenosyl-l-methionine Enzyme with an Additional [4Fe-4S]+2 Cluster That Interacts with the Pyruvate Co-substrate*

    Science.gov (United States)

    Perche-Letuvée, Phanélie; Kathirvelu, Velavan; Berggren, Gustav; Clemancey, Martin; Latour, Jean-Marc; Maurel, Vincent; Douki, Thierry; Armengaud, Jean; Mulliez, Etienne; Fontecave, Marc; Garcia-Serres, Ricardo; Gambarelli, Serge; Atta, Mohamed

    2012-01-01

    Wybutosine and its derivatives are found in position 37 of tRNA encoding Phe in eukaryotes and archaea. They are believed to play a key role in the decoding function of the ribosome. The second step in the biosynthesis of wybutosine is catalyzed by TYW1 protein, which is a member of the well established class of metalloenzymes called “Radical-SAM.” These enzymes use a [4Fe-4S] cluster, chelated by three cysteines in a CX3CX2C motif, and S-adenosyl-l-methionine (SAM) to generate a 5′-deoxyadenosyl radical that initiates various chemically challenging reactions. Sequence analysis of TYW1 proteins revealed, in the N-terminal half of the enzyme beside the Radical-SAM cysteine triad, an additional highly conserved cysteine motif. In this study we show by combining analytical and spectroscopic methods including UV-visible absorption, Mössbauer, EPR, and HYSCORE spectroscopies that these additional cysteines are involved in the coordination of a second [4Fe-4S] cluster displaying a free coordination site that interacts with pyruvate, the second substrate of the reaction. The presence of two distinct iron-sulfur clusters on TYW1 is reminiscent of MiaB, another tRNA-modifying metalloenzyme whose active form was shown to bind two iron-sulfur clusters. A possible role for the second [4Fe-4S] cluster in the enzyme activity is discussed. PMID:23043105

  7. 共基质对10株细菌降解苯并芘的作用研究%Effects of Co-Substrates on the Biodegradation of Benzo[a]pyrene by Ten Bacteria Strains

    Institute of Scientific and Technical Information of China (English)

    苏丹; 李培军; 台培东; E.V.Verkhozina

    2007-01-01

    从石油污染的污泥中分离驯化出10株细菌(SB01~SB10),利用生物摇床实验对其降解苯并芘(BaP)的效能进行试验,研究了有(或无)共基质(葡萄糖Glu,或菲PHE)对细菌降解BaP的影响,并采用ANOVA和Tukey多重比较进行分析.结果表明,(1)当以BaP为惟一碳源和能源且BaP初始浓度为50 mg·L-1时(MS1),SB01的降解率最高,5 d可降解31.0%;以Glu为共代谢基质时(MS2),SB09的降解率最高,可达36.9%;以PHE为共代谢基质时(MS3),SB01对BaP的降解率为46.0%.(2)Glu对SB01、SB02、SB03、SB07、SB10降解BaP有抑制作用,对SB01抑制作用最明显,使SB01的降解率降低了13.1%,Glu对SB05,SB08降解率无明显促进或抑制作用.(3)PHE对细菌降解BaP均表现出促进作用,对SB01的促进作用最明显,使其降解率提高15.0%.(4)Glu对SB09的促进作用大于PHE的促进作用,而对SB06,PHE的促进作用大于Glu.

  8. Anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure in a single continuously stirred tank reactor process: Limits in co-substrate ratios and organic loading rate.

    Science.gov (United States)

    Rico, Carlos; Muñoz, Noelia; Rico, José Luis

    2015-01-01

    Mesophilic anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure was investigated with the aim of determining the treatment limits in terms of the cheese whey fraction in feed and the organic loading rate. The results of a continuous stirred tank reactor that was operated with a hydraulic retention time of 15.6 days showed that the co-digestion process was possible with a cheese whey fraction as high as 85% in the feed. The efficiency of the process was similar within the range of the 15-85% cheese whey fraction. To study the effect of the increasing loading rate, the HRT was progressively shortened with the 65% cheese whey fraction in the feed. The reactor efficiency dropped as the HRT decreased but enabled a stable operation over 8.7 days of HRT. At these operating conditions, a volumetric methane production rate of 1.37 m(3) CH4 m(-3) d(-1) was achieved.

  9. Utilization of wasted sardine oil as co-substrate with pig slurry for biogas production--a pilot experience of decentralized industrial organic waste management in a Portuguese pig farm.

    Science.gov (United States)

    Ferreira, L; Duarte, E; Figueiredo, D

    2012-07-01

    This work aimed to demonstrate in a pig farm and in real conditions, the possibilities to co-digest wasted sardine oil (WSO) and pig slurry (PS) at farm scale. A biogas mobile pilot plant, was set up in the farm and operated in real conditions during 4 months. Dynamic mesophilic (35-37 °C) continuous pilot trials were performed during four different periods of time. In each period a different organic loading rate (OLR) based on the chemical oxygen demand (COD) was operated sequentially, with pig slurry (PS) (OLR = 1.6 kg COD/m(3) d(-1)) and with mixtures of WSO:PS with a volumetric composition (% v/v) of 2:98 (OLR = 3.0 kg COD/m(3) d(-1)), 3:97 (OLR = 3.7 kg COD/m(3) d(-1)) and 5:95 (OLR = 5.2 kg COD/m(3) d(-1)). Biomass adapted very fast in metabolise the WSO and biogas productivity was raised substantially for different compositions of WSO:PS. Process stability indicators pH and Total volatile fatty acids/bicarbonate alkalinity (T-VFA/BA) ratio, suggests that the co-digestion process was robust. It was concluded that WSO could be easily co-digested in farm scale biogas plants. Copyright © 2012. Published by Elsevier Ltd.

  10. Effect of co-substrate on production of poly-β- hydroxybutyrate (PHB and copolymer PHBV from newly identified mutant Rhodobacter sphaeroides U7 cultivated under aerobic-dark condition

    Directory of Open Access Journals (Sweden)

    Kemarajt Kemavongse

    2007-07-01

    Full Text Available Photosynthetic bacterial mutant strain U7 was identified using both classical and molecular (16S rDNA techniques to be Rhodobacter sphaeroides. The glutamate-acetate (GA medium containing sodium acetate and sodium glutamate as carbon and nitrogen sources was used for production of poly-β-hydroxybutyrate (PHB from R. sphaeroides U7 cultivated under aerobic-dark condition (200 rpm at 37oC. Effect of auxiliary carbon sources (propionate and valerate and concentrations (molar ratio of 40/0, 40/20, 40/40 and 40/80 on copolymer production were studied. Both combinations of acetate with valerate and acetate with propionate were found to induce the accumulation of poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV within the cell. Acetate with propionate in the molar ratio of 40/40 gave the highest poly-β-hydroxyalkanoates (PHA content (77.68%, followed by acetate with valerate at the same molar ratio (77.42%. Although their polymer contents were similar, the presence of 40 mM valerate gave more than 4 times higher hydroxyvalerate (HV fraction (84.77% than in the presence of 40 mM propionate (19.12% HV fraction.

  11. Influence of tensides and lipophilic substrates on the biological availability of polycyclic aromatic hydrocarbons (PAHs); Ueber dem Einfluss von Tensiden und lipophilen Substraten auf die Bioverfuegbarkeit von polyzyklischen aromatischen Kohlenwasserstoffen (PAK)

    Energy Technology Data Exchange (ETDEWEB)

    Soeder, C.J. von; Kleespies, M.; Eschner, C.; Webb, L.; Groeneweg, J. [Forschungszentrum Juelich GmbH (Germany). IBT-3/ICG-6

    1997-12-31

    The objects of the study were as follows: isolation and characterization of PAH-degrading micro-organisms from lysimeters; tests relating to the experimental simulation of the conditions permitting pollutant degradation in soil; investigation of the influence of tensides and other dissolved organic compounds on the biological availability and degradation of PAHs. (orig./SR) [Deutsch] - Isolierung und Charakterisierung PAK-abbauender Mikroorganismen aus Lysimetern; Versuche zur experimentellen Simulation der Bedingungen, unter denen der Abbau von Schadstoffen im Boden erfolgt. - Untersuchung des Einflusses von Tensiden und anderen geloesten organischen Verbindungen auf Bioverfuegbarkeit und Abbau von PAK. (orig./SR)

  12. Investigations of microbial regeneration of abandoned mining land. Project 1: Leachate reduction in ore mining regions with high levels of heavy metal sulfides. Final report 2000; Untersuchungen zur mikrobiellen Sicherung von Bergbaualtlasten. Teilvorhaben 1: Laugungsreduzierung in Schwermetallsulfid-belasteten Erzbergbauregionen. Abschlussbericht 2000

    Energy Technology Data Exchange (ETDEWEB)

    Sand, W.; Jozsa, P.G.; Schippers, A.

    2001-02-01

    The project was aimed at the development of an optimized catalogue of measures for regeneration and reclamation of polluted mining land. Reports were published in 1995, 1996, 1997 and 1998. This report summarizes the work of 1999 and 2000. A catalogue of measures is proposed on the basis of the results. [German] Ziel des Projektes ist die Erarbeitung eines optimierten Massnahmenpaketes zur Sicherung und Sanierung von Bergbaualtlasten, die durch mikrobiologische Sauerwasserbildung und Schwermetallmobilisierung Boeden und Gewaesser kontaminieren. Die Problematik und der Stand der Kenntnisse sowie erste Ergebnisse der Bestandsaufnahmen wurden in den Jahresberichten 1995 und 1996 sowie im Fortsetzungsantrag ausfuehrlich dargestellt. Ueber die Versuchsergebnisse der Jahre 1997 und 1998 wurde bereits berichtet. Im Folgenden werden die in den Jahren 1999 und 2000 erzielten Ergebnisse zusammengefasst und eine Bewertung der Projektarbeit vorgenommen. Abschliessend wird ein Massnahmenkatalog vorgeschlagen, der bei der Planung und Durchfuehrung von Sanierungsaufgaben an Bergbaualtlasten den Anwendern die aus mikrobiologischer Sicht zu beruecksichtigenden Aspekte mit Loesungsmoeglichkeiten gebuendelt zur Verfuegung stellt. (orig.)

  13. Diagnostic real-time PCR for detection of Salmonella in food and characterization of epidemiologically important Salmonella enterica subsp. enterica serovars isolated from livestock, food and humans

    OpenAIRE

    Malorny, Burkhard

    2014-01-01

    Die mikrobiologische Routinediagnostik für Salmonella besteht traditionell aus Kultur-basierten Nachweisverfahren und der Identifizierung des Mikroorganismus auf Spezies-Level, sowie der Differenzierung in bestimmte Phänotypen durch serologische Verfahren. Eine weitergehende Diskriminierung, z.B. im Fall von Überwachungs- und epidemiologischen Studien, erfolgt durch antimikrobielle Resistenz- als auch Phagentypisierung. Zusätzlich hat die mikrobielle Genotypisierung in den vergangenen zwei Ja...

  14. Microbial reduction of methane emissions. Subproject 1: Development of a biofilter system for the degradation of methane, odours and trace gases for actively vented landfills. Subproject 2: Development of a biofilter system for the degradation of methane, odours and trace gases for passively vented landfills. Subproject 3: Planning, development and realisation of medium and large scale biofilter plants at active and passive gas drainage systems. Final report; Mikrobielle Verminderung von Methanemissionen. Teilvorhaben 1: Entwicklung eines Biofilterverfahrens zum Abbau von Methan, Geruechen und Spurengasen bei der aktiven Deponieentgasung. Teilvorhaben 2: Entwicklung eines Biofilterverfahrens zum Abbau von Methan, Geruechen und Spurengasen bei der passiven Deponieentgasung. Teilvorhaben 3: Planung, Entwicklung und Realisation halb- und grosstechnischer Biofilteranlagen an aktiven und passiven Entgasungssystemen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stegmann, R.; Streese, J.; Dammann, Bernd; Gebert, J.; Groengroeft, A.; Miehlich, G.; Schulze, H.; Berndt, M.

    2003-07-01

    Old landfills may emit considerable amounts of methane, carbon dioxide and trace gases. However, gas flow rate and methane content are usually too low for energetic utilization or flaring of the landfill gas. Microbial degradation is considered an alternative treatment for the reduction of methane emissions from those sites. The project aimed in the investigation of the suitability of actively vented biofilters for this purpose and the collection of operational experience and dimensioning data for large scale applications of the process. Different experimental plants were operated in laboratory scale (filter volume: 60 L) and container scale (filter volume: 4 m{sup 3}). The laboratory scale plant was operated with synthetic methane, whereas the container scale plant was set up at an old landfill and operated with real landfill gas. For each plant, the gas was diluted with ambient air prior to feeding into the closed biofilters, thus sufficient oxygen for methane oxidation was present throughout the filter material. At first, fine-grained compost as biofilter material was investigated. A biofilter unit of 15 m{sup 3} size containing porous clay pellets as filter material was integrated into the recultivation layer of a Hamburg harbour sludge landfill. The parameters of landfill gas emission as well as the abiotic parameters of biofilter operation were monitored by a high-resolution automatic data collection system and gas distribution and gas emissions via the biofilter surface measured regularly. In addition, microbiological laboratory studies and studies concerning physical questions of biofilter operations were conducted. (orig.)

  15. 蔗糖与葡萄糖作辅助碳源对重组Klebsiella pneumoniae发酵生产1,3-丙二醇的影响%Effect of Sucrose and Glucose as Cosubstrate on 1,3-Propanediol Fermentation by Recombinant Klebsiella pneumoniae

    Institute of Scientific and Technical Information of China (English)

    吴家鑫; 王凤寰; 王峥; 谭天伟; 刘沛溢

    2014-01-01

    实验研究了重组Klebsiella pneumoniae批式发酵生产1,3-丙二醇过程中辅助碳源蔗糖与葡萄糖对发酵过程的影响,对发酵工艺进行了放大,并对流加策略进行了优化.结果表明,葡萄糖为发酵生产1,3-丙二醇的辅助碳源优于蔗糖;以重组Klebsiella pneumoniae为菌种,以葡萄糖为辅助碳源,采用指数流加策略,30L发酵罐中1,3-丙二醇的产量最高达85.2 g/L,产率达0.63 mol/mol,比单纯以甘油为碳源分别提高37.35%和25.00%.

  16. Application of molecular biological methods in groundwater and drinking water analysis. Papers and discussions; Anwendung molekularbiologischer Verfahren in der Grund- und Trinkwasseranalytik. Textbeitraege und Diskussionsergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlmann, B.; Preuss, G. (eds.)

    2000-07-01

    Water management and water supply make demands on microbiology which so far were difficult to meet. However, new molecular-biological methods were developed by ecologically oriented scientists which open up new options in groundwater and freshwater analysis. [German] Aus dem Bereich der Wasserwirtschaft und -versorgung werden vermehrt Anforderungen und Fragen an die Mikrobiologie gestellt, die bisher aufgrund der eingeschraenkten methodischen Moeglichkeiten nur unzureichend beantwortet werden konnten. In unterschiedlichen, meist oekologisch orientierten Forschungsbereichen wurden jedoch neue, im Wesentlichen molekularbiologische Methoden entwickelt, die auch in Hinblick auf die mikrobiologische Untersuchung des Grund- und Trinkwassers neue Perspektiven eroeffneten. (orig.)

  17. Wirkung von Starter- und Schutzkulturen sowie ihrer Metabolite auf die Infektiosität von murinem Norovirus S 99 und Influenzavirus H1N1 in kurzgereiften Rohwürsten

    OpenAIRE

    2014-01-01

    Viren haben als Ursache lebensmittelassoziierter Infektionen eine große Bedeutung. Sie können vor allem über rohe oder unzureichend erhitzte Lebensmittel übertragen werden. In diesem Zusammenhang werden grüner Salat, Erdbeeren, Himbeeren, Frühlingszwiebeln, Muscheln, halbgetrocknete Tomaten, fäkal verunreinigtes Trinkwasser, Backwaren und Rohwürste als häufige Infektionsquellen genannt. Vor allem kurzgereifte Rohwürste gehören aus mikrobiologischer Sicht zu Risikoprodukten. Um eine gleichblei...

  18. More efficient redox biocatalysis by utilising 1,4-butanediol as a ‘smart cosubstrate’

    NARCIS (Netherlands)

    Kara, S.; Spickermann, D.; Schrittwieser, J.H.; Leggewie,C.; Van Berkel, W.J.H.; Arendsa, I.W.C.E.; Hollmann, F.

    2012-01-01

    1,4-Butanediol is shown to be an efficient cosubstrate to promote NAD(P)H-dependent redox biocatalysis. The thermodynamically and kinetically inert lactone coproduct makes the regeneration reaction irreversible. Thereby not only the molar surplus of cosubstrate is dramatically reduced but also faste

  19. Europäische Nachbarschaftspolitik: eine erste Bilanz

    OpenAIRE

    Zorob, Anja

    2007-01-01

    Im Dezember 2006 stellte die Europäische Kommission die Ergebnisse der ersten 18 Monate der Implementierung der Europäischen Nachbarschaftspolitik (ENP) vor. Diese ersten "Ergebnisse" fallen trotz länderspezifischer Unterschiede und auch eingedenk der relativ kurzen Zeitspanne moderat aus. Die ENP kann die wichtigsten Hemmfaktoren des Barcelona-Prozesses nicht wirklich beheben. Dazu zählen die schleppende Liberalisierung des Agrar- und Dienstleistungshandels, der ungenügende Abbau nichttarifä...

  20. Phytoremediation organischer Schadstoffe mit Hilfe von Phragmites australis

    OpenAIRE

    Neustifter, Juliane Erika

    2007-01-01

    Praxisorientierte Projekte an einer Kläranlage lieferten umfassende Einblicke in einen mit Phragmites australis, dem Schilfrohr, bepflanzten Bodenfilter und seine jahreszeitlichen Rhythmen. Es wurde festgestellt, dass der Filter eine ausgezeichnete Restreinigung und Pufferwirkung hat und sogar verschiedene endokrin wirksame Substanzen zurückhält. Es konnte gezeigt werden, dass Phragmites australis organische Schadstoffe aufnehmen kann und wichtige Entgiftungsenzyme für den Abbau dieser Xenobi...

  1. Adrenomyeloneuropathie, eine seltene Ursache der primären Nebenniereninsuffizienz

    OpenAIRE

    Frank, K; Schrecker, O.; Brosi, K.; Krause, Klaus-Henning; Vecsei, K.-H.; Moser, H W; Ziegler, R.

    1986-01-01

    Eine seltene Ursache der primären Nebennierenrindeninsuffizienz ist die X-chromosomal vererbte Adrenomyeloneuropathie. Neurologisch ist sie durch Zeichen der zentralen und peripheren Demyelinisierung, endokrinologisch durch einen M. Addison und eine zusätzliche primäre Hodeninsuffizienz gekennzeichnet. Bei zwei Patienten mit diesem Krankheitsbild konnte der Stoffwechseldefekt im Abbau langkettiger Fettsäuren durch Bestimmung eines erhöhten Hexakosansäure-Spiegels (C 26) im Blut gesichert werd...

  2. Externe Effekte der Laufwasserkraftnutzung

    OpenAIRE

    Kohler, Beate

    2006-01-01

    In den vergangenen Jahrzehnten hat eine zunehmende Sensibilisierung bzgl. der Vermeidung von Umweltbelastungen im Zusammenhang mit dem Abbau und dem Verbrauch natürlicher Ressourcen stattgefunden. Das Thema ist nicht nur Gegenstand von Wissenschaft und Politik, sondern wird von einer breiten Öffentlichkeit diskutiert. Da Energieerzeugung stets an die Nutzung und insofern auch an die Belastung natürlicher Ressourcen gebunden ist, betrifft diese Thematik Energieversorgungsunternehmen in besonde...

  3. Untersuchungen zur Trockenentschwefelung von Brenngasen durch Partialoxidation von H2S an Herdofenkoks

    OpenAIRE

    Bauersfeld, Dirk

    2009-01-01

    Die vorliegende Arbeit befasst sich mit Untersuchungen zur Trockenentschwefelung von Brenngasen durch Partialoxidation von H2S an Herdofenkoks. Hierzu wurden Versuche in der Technikumsanlage VTE 2004 mit einem simulierten PHTW Gas durchgeführt. Es zeigte sich, dass der COS-Abbau nicht wie bisher angenommen durch die COS-Partialoxidation sondern durch die COS-Hydrolyse erfolgt. Die COS-Hydrolyse gewinnt dabei mit abnehmender Raumbelastung an Bedeutung. Der Entschwefelungsgrad erhöht sich mit s...

  4. Biotechnological in-situ-remediation of soil and groundwater by degradation of petrochemical and other organic pollutants - analysis and evaluation. Final report. - Study about the state of in-situ-treatment methods for contaminated land and view of development of in-situ-methods in future. Untersuchung und Bewertung von in situ-biotechnologischen Verfahren zur Sanierung des Bodens und des Untergrundes durch Abbau petrochemischer Altlasten und anderer organischer Umweltchemikalien. Schlussbericht. - Untersuchung zur Erfassung des Standes der Technik der in situ-Sanierungsverfahren von Altlasten und Ausblick auf zukuenftige Entwicklung der Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Filip, Z.; Geller, A.; Schiefer, B.; Schwefer, H.J.; Weirich, G.; Stiefel, R.; Joeckel, R.

    1989-01-01

    The report reflects a current state of the biotechnological in-situ remediation technique in chemically polluted soil and groundwater environments. Main groups of common organic contaminants have been considered and their relationships with soil and groundwater micoorganisms have been discussed. Specific factors related to soil hydrogeological and engineering conditions which are of importance for the biological degradation of contaminants have been also evaluated. Biological and physicochemical aspects of monitoring are discussed. A review is given of the analytical equipment available at the market of the FRG. Ten typical remediation projects have been analysed and evaluated. On this basis, a model remediation system for a site contaminated by mineral oil has been proposed. (orig.) With 179 refs., 29 tabs., 23 figs.

  5. Geomicrobiological analysis of highly mineralized geothermal waters as a contribution to the optimum use of geothermal energy; Geomikrobiologische Forschungsarbeiten an hochmineralisierten Tiefenwaessern als Beitrag zur optimalen Nutzung geothermischer Energie

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, M.; Voelsgen, F.; Hofmann, K.; Bochning, S. [URST Umwelt- und Rohstoff-Technologie, Greifswald (Germany); Keller, T. [Geothermie Neubrandenburg GmbH (Germany)

    1997-12-01

    In the context of a BMBF-funded project for Mecklenburg-Vorpommern, `Geomicrobiological analysis of geothermal waters used for energy generation`, the authors continued the series of microbiological analyses of the thermal water of the geothermal heating station at Neustadt-Glewe beyond full commissioning of the plant in April 1995. Their activities also included performance of model experiments for examination of the conditions causing massive development of microorganisms in the aquifer or in the thermal water loops of the heating station. The experimental results show that compliance with the findings and recommended operational measures will guarantee long-term operating stability of the heating station. However, in-service microbiological monitoring routines are required in order to early detect and prevent unwanted processes in the thermal water system. (orig.) [Deutsch] Im Rahmen des vom BMBF gefoerderten Projektes `Geomikrobiologische Untersuchungen an geothermisch genutzten Tiefenwaessern Nordostdeutschlands` (Mecklenburg-Vorpommern) haben wir uns auch nach voller Inbetriebnahme des Erdwaerme-Heizwerkes Neustadt-Glewe (April 1995) auf die mikrobiologische Analyse des Thermalwassers konzentriert. Darueber hinaus wurde in Modellversuchen geprueft, unter welchen Bedingungen eine Massenentwicklung von Mikroorganismen im Aquifer bzw. Thermalwasserkreislauf moeglich ist. Die Versuche haben gezeigt, dass unter Beachtung der erzielten Befunde bei sachgemaesser Betriebsfuehrung die Langzeitstabilitaet der Anlage gewaehrleistet ist. Jedoch sind mikrobiologische Betriebskontrollen unerlaesslich, um unerwuenschte Prozesse im Thermalwassersystem rechtzeitig erkenn en und verhindern zu koennen. (orig.)

  6. GTP plus water mimic ATP in the active site of protein kinase CK2

    DEFF Research Database (Denmark)

    Niefind, K; Pütter, M; Guerra, B

    1999-01-01

    The structures of the catalytic subunit of protein kinase CK2 from Zea mays complexed with Mg2+ and with analogs of ATP or GTP were determined to 2.2 A resolution. Unlike most other protein kinases, CK2 from various sources shows 'dual-cosubstrate specificity', that is, the ability to efficiently...... use either ATP or GTP as a cosubstrate. The structures of these complexes demonstrate that water molecules are critical to switch the active site of CK2 from an ATP- to a GTP-compatible state. An understanding of the structural basis of dual-cosubstrate specificity may help in the design of drugs...

  7. Potential of glycerol and soybean oil for bioremediation of weathered oily-sludge contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, T.C.F.; Franca, F.P. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica], E-mail: fpfranca@eq.ufrj.br; Oliveira, F.J.S. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-04-15

    The bioremediation of petroleum-contaminated soil was investigated on laboratory scale. This work evaluated the effect of co-substrate addition in tropical climate soil highly contaminated with oily residue. Glycerol and soybean oil were used as auxiliary co-substrates for contaminant degradation. Three different concentrations of co-substrate were tested, and the experiments were carried out over 60 days. The following parameters were monitored: humidity, pH, total heterotrophic bacteria, total fungi, total petroleum hydrocarbons (TPH), and the concentrations of benzo[a]pyrene and chrysene. The soil supplementation with renewable co-substrates improved the efficiency of the biodegradation TPH, with removals of 85% and 83% for glycerol and soybean oil, respectively, compared to a 55% removal yielded by the biodegradation process without supplementation. The use of glycerol increased Chrysene and Benzo[a]pyrene biodegradation by 50%, while soybean oil supplementation increased their removal by 36%. (author)

  8. Structure and function of dioxygenases in histone demethylation and DNA/RNA demethylation

    National Research Council Canada - National Science Library

    Dong, Cheng; Zhang, Heng; Xu, Chao; Arrowsmith, Cheryl H; Min, Jinrong

    2014-01-01

    Iron(II) and 2-oxoglutarate (2OG)-dependent dioxygenases involved in histone and DNA/RNA demethylation convert the cosubstrate 2OG and oxygen to succinate and carbon dioxide, resulting in hydroxylation of the methyl group...

  9. I distrust self-declared patent solutions. Interview with Dr. Angela Merkel, Federal Minister of the Environment; Mich stoeren vermeintliche Patentrezepte. Interview mit Bundesumweltministerin Dr. Angela Merkel

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, A. [Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany); Roehrlich, D.

    1995-12-31

    Dr. Merkel answered questions on energy supply and environmental protection. The following subjects were discussed: Efficient use of energy, legal regulations, energy mix, developments in nuclear technology, better acceptance of renewable energy sources, nuclear phase-out - not a feasible alternative, increasing acceptance of waste incineration plants. (BWI) [Deutsch] Der vorliegende Beitrag gibt ein Interview mit der Bundesumweltministerin Merkel zu Fragen der Energieversorgung und des Umweltschutzes wider. In diesem Zusammenhang werden folgende Themenbereiche diskutiert: Effizientere Energienutzung, rechtliche Regelungen, Zusammensetzung der eingesetzten Energietraeger, Weiterentwicklung der Kerntechnologie, Abbau von Hemmnissen bei erneuerbaren Energiequellen, Verzicht auf Kernkraft nicht sinnvoll, zunehmende Akzeptanz fuer Muellverbrennungsanlagen. (BWI)

  10. CYP2D6-Genotyping in clinical practice: Impact of genotype on serum concentrations of psychiatric CYP2D6-substrates

    OpenAIRE

    Plodeck, Verena

    2010-01-01

    Cytochrom P450 2D6 spielt beim Abbau vieler Psychopharmaka eine wichtige Rolle. Es ist seit längerem bekannt, dass für CYP2D6 ein genetischer Polymorphismus existiert. Dieser führt dazu, dass die metabolischen Kapazitäten interindividuell stark variieren. Man spricht in diesem Zusammenhang von poor, intermediate, extensive und ultra-fast metabolizern. Das Ziel dieser Arbeit war es, die Auswirkungen des Genotyps auf die Serumkonzentrationen und somit auch die Verträglichkeit bzw. den Therapiee...

  11. Späte Mutterschaft – (keine biografische Entscheidung

    Directory of Open Access Journals (Sweden)

    Martina Beham

    2004-11-01

    Full Text Available Der Übergang in die Mutterschaft findet zunehmend später statt. Über die Gründe liegen zahlreiche Vermutungen und einige theoretische Diskussionen, aber kaum empirische Befunde vor. Die Autorinnen möchten mit ihrer Studie einen Beitrag zum Abbau dieses Forschungsdefizits leisten. In ihrer empirisch-biografischen Untersuchung gehen Ingrid Herlyn und Dorothea Krüger der Frage nach, ob späte Erstmutterschaft ein neues biografisches Muster der Familiengründung darstellt oder ob Mutterschaft nach wie vor eine selbstverständlich anerkannte Norm ist, deren Realisierung im Lebenslauf lediglich zeitlich später stattfindet.

  12. Structure and energetics of Ni clusters with up to 150 atoms

    CERN Document Server

    Grigoryan, V G

    2003-01-01

    We present a method (the Aufbau/Abbau method) for optimizing the structure of a whole series of clusters without making any assumptions on the structure. Subsequently, the method is combined with the embedded-atom method in determining the structure of the two energetically lowest isomers of Ni_N clusters with N up to 150. Finally, various analytical descriptors are introduced that are used in studying the overall shape of the clusters, their structure and stability, and possible growth and dissociation processes.

  13. Investigations of the acceleration of microbial degradation of PAH in soils with high PAH contamination by coffein in practical conditions. Final report; Untersuchungen zur Beschleunigung des mikrobiellen Abbaus von polycyclischen aromatischen Kohlenwasserstoffen in Boeden mit hoher PAH-Kontamination durch Coffein unter Praxisbedingungen. Anhang. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grimmer, G.; Collins, H.J.

    1998-01-01

    fAH degradation by Mucor circinelloides was proved several times in the course of this project. Although PAH contamination could never be completely removed, a number of parameters were identified that influence successful PAH degradation, e.g. soil homogeneity, oxygen supply to the microorganisms, pH, and nutrient supply. The effect of the complexing agent coffein on PAH degradation, which had been described already in preliminary investigations, was validated several times. Optimisation experiments showed that the pre-determined optimum coffein concentration of 0.3% in the nutrient broth provided the best results also in the present investigations. There was no suggestion of a negative effect of various cations on the growth of Mucor circinelloides which may be mobilized in the soils by the acid nutrient broth. A comparison of residual PAH concentrations after microbial treatment in the model soil ``tar-pitch-doped quartz sand`` and the soil ``gas works`` showed that different residual concentrations must be expected depending on the soil material. This volume presents a summary of the results. (orig./SR) [Deutsch] Im Rahmen dieses Projektes konnte der Abbau von PAH durch Mucor circinelloides mehrfach nachgewiesen werden. Es wurde in keinem Fall eine vollstaendige Entfernung der PAH-Kontamination erreicht, jedoch stellten sich eine Reihe von Parametern als wesentlich fuer einen erfolgreichen PAH-Abbau heraus (Homogenitaet des Bodenmaterials, Versorgung der Mikroorganisme mit Sauerstoff, pH-Wert, Naehrstoffversorgung). Der bereits in Voruntersuchungen beschriebene Effekt des Komplexbildners Coffein auf den PAH-Abbau wurde bei den durchgefuehrten Untersuchungen mehrfach bestaetigt. Optimierungsexperimente fuehrten zu dem Ergebnis, dass die bereits als optimal ermittelte Coffeinkonzentration von 0,3% im Naehrmedium auch fuer die hier untersuchten Boeden die besten Ergebnisse liefert. Ein negativer Einfluss verschiedener Kationen auf das Wachstum von Mucor

  14. Fortwährende Emanzipation

    Directory of Open Access Journals (Sweden)

    Susanne Lepsius

    2004-07-01

    Full Text Available Grimme stellt die Entwicklung der Emanzipation der Frau als „Abbau patriarchalischer Strukturen“ von der fränkischen Zeit bis zum Gleichberechtigungsgesetz von 1957 dar. Vorrangig betrachtet er dabei die rechtlichen Bestimmungen, die die Stellung der Ehefrau charakterisierten. Er stellt dabei (außer bei den Einschränkungen in der Frühen Neuzeit und dem völligen Rückschlag im Nationalsozialismus eine weitgehend ungebrochene historische Aufwärtsentwicklung fest, die zu vielen kritischen Rückfragen Anlass gibt.

  15. Development of a method for the simultaneous treatment of oily and communal waste waters. Final report; Entwicklung eines Verfahrens zur simultanen biologischen Behandlung von veroeltem und kommunalem Abwasser. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schloericke, W.; Raasch, F.; Lieske, U.; Lewerenz, S.; Schneider, S.; Hesse, D.

    1993-09-01

    In this research project a concept was elaborated for a purification plant for oily waste water. The hydrocarbons are decomposed aerobically in a fixed-bed bioreactor. A plastic base material is used for the biomass. The purified water is in keeping with the legal limit values. (EF) [Deutsch] Im vorliegenden Forschungsbericht wurde ein Anlagenkonzept zur Reinigung oelhaltigen Abwassers erarbeitet. Der aerobe Abbau der Kohlenwasserstoffe erfolgte in einem Testbett-Bioreaktor. Als Traegermaterial fuer die Biomasse wurde Kunststoff verwendet. Das gereinigte Abwasser entspricht den gesetzlichen Bestimmungen. (EF)

  16. Struktur und Funktionsmechanismus der mitochondrialen m-AAA-Protease aus S. cerevisiae

    OpenAIRE

    Augustin, Steffen

    2008-01-01

    ATP-abhängige Proteasen (AAA+ Proteasen) nutzen die Energie aus der ATP-Hydrolyse, um Substratproteine zu entfalten und in eine proteolytische Kammer zu translozieren, in der der Abbau zu Peptiden erfolgen kann. In der mitochondrialen Innenmembran der Hefe S. cerevisiae sind zwei konservierte ATP-abhängige Proteasen lokalisiert, die homo-oligomere i-AAA-Protease und die hetero-oligomere m-AAA-Protease; letztere ist aus Yta10- und Yta12-Untereinheiten aufgebaut. Weder der katalytische Mechanis...

  17. Treatment of sediments from soil washing plants. Investigation of the suitability of a gas/solids fluidized bed bioreactor for the decontamination; Bodenwaschanlagen-Sedimente behandeln. Untersuchungen der Eignung des Gas/Feststoff-Wirbelschicht-Bioreaktors zur Dekontaminierung

    Energy Technology Data Exchange (ETDEWEB)

    Behns, W.; Haida, H. [Magdeburg Univ. (Germany). Inst. fuer Apparate- und Umwelttechnik; Friedrich, C. [Allgaier-Werke, Uhingen (Germany)

    1997-09-01

    This article deals with the possibility of microbiological decontamination of sediments from soil washing plants in gas/solids fluidized bed bioreactors. The sediments are pressed to granulates. The pollutants which are removed are mineral oil hydrocarbons. The degradation results of this process are presented, the process seems to be an alternative to common waste treatment processes. (SR) [Deutsch] Die mikrobiologische Dekontaminierung sandiger Boeden in einem Gas/Feststoff-Wirbelschicht-Bioreaktor ist eine erfolgversprechende Alternative zu anderen biologischen Reinigungsverfahren. Die biologische Dekontaminierung von Schlufffraktionen oder von Bodenwaschanlagensedimenten (BWS) ist deutlich schwieriger. In der Literatur werden vor allem Verfahren unter Einsatz von Suspensionsreaktoren verwendet, um fuer Feinkorn-Fraktionen eine biologische Reinigung zu ermoeglichen. Hier soll ueber Untersuchungen berichtet werden, mit denen die Eignung des Gas/Feststoff-Wirbelschicht-Bioreaktors fuer die Dekontaminierung derartiger Boeden ueberprueft werden sollte. (orig.)

  18. Using a laser guidance system for CT-guided biopsy and treatment of nerve block; Verwendung eines Laserzielgeraetes fuer CT-gesteuerte Biopsien und Nervenblockaden

    Energy Technology Data Exchange (ETDEWEB)

    Zwaan, M. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany); Frahm, C. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany); Kloess, W. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany); Preuss, S. [Schmerzambulanz, Klinik fuer Anaesthesiologie, Medizinische Univ. Luebeck (Germany); Baumeier, W. [Schmerzambulanz, Klinik fuer Anaesthesiologie, Medizinische Univ. Luebeck (Germany); Grande-Nagel, I. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany); Gehl, H.B. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany); Weiss, H.D. [Inst. fuer Radiologie, Medizinische Univ. Luebeck (Germany)

    1996-07-01

    CT-guided intervention is a simple and pin-pointed modality for obtaining cytologic, biopsy, or microbiologic samples, and for treatment of the nerve blockade. In order to enhance the precision of punctures, and reduce complications, the authors developed and tested a novel laser guidance system (wavelength 365 nm at 4.5 mW). In 56 consecutive patients (representing 24 nerve blocks, 16 tumor biopsies, 16 microbiological punctures), a CT-guided intervention was performed. Despite a high accuracy (80 punctures), false punctures (6) could not be avoided in cases where anatomic conditions were misleading the needle, or due to patient movements. The system is not to be blamed for these unsuccessful attempts. As the system operates contactless guided by laser light, it is a good tool ensuring simple and sterile needle biopsy. (orig.) [Deutsch] Die computertomographisch gesteuerte Intervention ist ein einfaches und zielsicheres Verfahren fuer die Gewinnung zystologischer, bioptischer oder mikrobiologischer Proben und zur therapeutischen Nervenblockade. Zur Erhoehung der Punktionsgenauigkeit und zur Reduktion von Komplikationen haben wir fuer diese Indikationsgebiete ein neu entwickeltes Laserzielgeraet (Wellenlaenge 365 m bei 4,5 mW) erprobt. Es wurde bei 56 konsekutiven Patienten (24 Nervenblockaden, 16 Tumorbiopsien, 16 mikrobiologische Materialentnahmen) eine CT-gesteuerte Intervention duchgefuehrt. Trotz einer hohen Treffgenauigkeit (80 Punktionen) kann es aber weiterhin zu Fehlpunktionen (6) kommen, falls Koerperstrukturen zum Abweichen oder Abbiegen der Punktionsnadel fuehren oder der Patient sich bewegt. Dies ist dem System selbst nicht anzulasten. Da es mit Laserlicht beruehrungsfrei arbeitet, ist eine einfache und sterile Punktion sehr gut moeglich. (orig.)

  19. Anreizkomponenten von Bonus-programmen der gesetzlichen Krankenversicherungen - Kommunikation als unterschätzte Erfolgskomponente

    Directory of Open Access Journals (Sweden)

    Gerd Glaeske

    2009-10-01

    Full Text Available Ziel: Die Bonusprogramme der gesetzlichen Krankenversicherungen (GKV sollen insbesondere Risikogruppen durch monetäre Anreize zu gesundheitsbewussten Verhaltensweisen stimulieren, um schlummernde präventive Rationalisierungspotenziale auszuschöpfen. Erste Studien deuten darauf hin, dass Mitnahmeeffekte (guter Risiken vor Präventionseffekte dominieren. Ziel des Beitrags ist es, die Erfolgsfaktoren von Anreizsystemen darzustellen.Methodik: Um den Stand der aktuellen Forschung zu identifizieren, wurde eine Literaturanalyse vorgenommen. Da die gesetzlich geforderten Effizienznachweise, nur die Kosten-Nutzen-Verhältnisse abbilden und keine übergreifenden Lerneffekte hinsichtlich einer optimierten Ausgestaltung zulassen, wurden ebenfalls Studien aus dem kommerziellen Bereich einbezogen, um mögliche Erfolgsfaktoren und Forschungsbedarf identifizieren zu können.Ergebnisse: Die Ergebnisse der Literaturanalyse macht deutlich, dass nicht allein die Kernelemente der Bonusprogramme, sondern Zusatzelemente (Erinnerungssysteme, Abbau von Barrieren einen bedeutende Rolle spielen, um die Teilnahmeraten von Präventionsinterventionen zu erhöhen.Schlussfolgerung: Zur Stimulierung gesundheitsbewussten Verhaltens sollte zukünftig verstärkt Augenmerk auf den Abbau von Informations-, Wissens- und Fähigkeitsbarrieren gelegt werden.

  20. Study to improve the bioavailability of polycyclic aromatic hydrocarbons (PAH). Ecological and toxicological evaluation of soils containing high PAH-concentration after biotechnological remediation (phase 1). Final report; Untersuchung zur Verbesserung der Bioverfuegbarkeit von polycyclischen aromatischen Kohlenwasserstoffen (PAH) und oekotoxikologische Bewertung biotechnologisch sanierter Boeden mit hohen PAH-Konzentrationen (Projektphase 1). Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grimmer, G.; Jacob, J.; Dettbarn, G.; Raab, G.

    1995-10-25

    It shall be clarified in a pre-study (phase I), whether (1) stable metabolites arise from the decomposition of various PAH, which are enriched during the remediation process of soil, and (2) whether caffeine used to increase the bioavailablity of the PAH in the soil will be decomposed by the microorganism used in the remediation process. For the metabolic studies described here the fungus Mucor circinelloides was used. Pyrene, chrysene and benzo[a]pyrene are decomposed to hydroxylated derivatives by Mucor circinelloides. Investigations for the biochemical reaction kinetics are made. (orig./SR) [Deutsch] In einer Vorstudie (Phase 1) soll geklaert werden, ob (1) stabile Stoffwechselprodukte beim Abbau der einzelnen PAH entstehen, die sich bei der Bodensanierung anreichern und (2) das zur Verbesserung der Bioverfuegbarkeit der PAH in den Boden eingebrachte Coffein durch die verwendeten Mikroorganismen abgebaut wird. Fuer die hier beschriebenen Stoffwechseluntersuchungen wurde der Pilz Mucor circinelloides verwendet. Pyren, Chrysen und Benzo[a]pyren werden durch Mucor circinelloides zu hydroxylierten Derivaten abgebaut. Fuer den biologischen Abbau wurden Unterscuhungen zur Kinetik durchgefuehrt. (orig./SR)

  1. Controlled composting of waste wood contaminated with PAH; Untersuchungen zur gesteuerten Rotte von mit polyzyklischen aromatischen Kohlenwasserstoffen (PAK) kontaminiertem Altholz

    Energy Technology Data Exchange (ETDEWEB)

    Ulbricht, H.

    2002-07-01

    The author investigated the potential and limits of microbial pollutant degradation in PAH-polluted waste wood by composting. The conditions in which autochthonic micro-organisms are able to decomposite the PAH contained in wood by solid phase fermentation were investigated. The focus was on phenanthrene, anthracene and pyrene, all of which are used as protective materials (disinfestants) for wood. The results were verified on contaminated waste wood, including an analytical investigations of decomposition of PAH of the EPA catalogue. Boundary conditions for achieving high rates of PAH decomposition were investigated. [German] Generelles Ziel der Arbeit war die Untersuchung der Moeglichkeiten und Grenzen des mikrobiellen Schadstoffabbaus in PAK-belastetem Altholz durch Kompostierung und die Pruefung auf Anwendbarkeit der Erkenntnisse in technischen Verfahren. In der vorliegenden Arbeit wurde untersucht, unter welchen Bedingungen die autochthonen Mikroorganismen in der Lage sind, an das Holz gebundene PAK durch Feststofffermentation abzubauen. Als Schwerpunkt wurde zunaechst der Abbau der im zum Holzschutz verwendetem Teeroel vorkommenden PAK Phenanthren, Anthracen und Pyren untersucht. Eine Verifizierung der Ergebnisse erfolgte mit real kontaminiertem Altholz, dabei wurde der Abbau der PAK der EPA-Liste analytisch verfolgt. Es sollten geeignete Randbedingungen gefunden werden, um im Festphasensystem hohe Abbauraten der PAK zu erreichen. (orig.)

  2. Biogas and biohydrogen production potential of high strength automobile industry wastewater during anaerobic degradation.

    Science.gov (United States)

    Bajaj, Mini; Winter, Josef

    2013-10-15

    High strength automobile industry wastewater, collected from decanters (DECA) of the pre-treatment plant after oil, grease and sludge separation, was investigated for production of methane in the absence and presence of glucose or excess aerobic sludge (AS) from a lab scale suspension reactor as co-substrates. The highest methane production from DECA wastewater was 335.4 L CH4/kg CODsoluble removal which decreased in the presence of the co-substrates to 232.5 (with 2 g/L glucose) and to 179 (with 40% AS) L CH4/kg CODsoluble removal, respectively. Around 95% of total methane was produced within 5 days of incubation of DECA at 37 °C when no co-substrate was added. Addition of co-substrates did not improve biodegradation of DECA but overall methane production from DECA + co-substrates was increased due to co-substrate biodegradation. The anaerobic inoculum, capable of producing 2.4 mol of hydrogen/mol of glucose under zinc induced inhibitory conditions, was unable to produce hydrogen from DECA as substrate under the same conditions.

  3. Synergistic co-digestion of solid-organic-waste and municipal-sewage-sludge: 1 plus 1 equals more than 2 in terms of biogas production and solids reduction.

    Science.gov (United States)

    Aichinger, Peter; Wadhawan, Tanush; Kuprian, Martin; Higgins, Matthew; Ebner, Christian; Fimml, Christian; Murthy, Sudhir; Wett, Bernhard

    2015-12-15

    Making good use of existing water infrastructure by adding organic wastes to anaerobic digesters improves the energy balance of a wastewater treatment plant (WWTP) substantially. This paper explores co-digestion load limits targeting a good trade-off for boosting methane production, and limiting process-drawbacks on nitrogen-return loads, cake-production, solids-viscosity and polymer demand. Bio-methane potential tests using whey as a model co-substrate showed diversification and intensification of the anaerobic digestion process resulting in a synergistical enhancement in sewage sludge methanization. Full-scale case-studies demonstrate organic co-substrate addition of up to 94% of the organic sludge load resulted in tripling of the biogas production. At organic co-substrate addition of up to 25% no significant increase in cake production and only a minor increase in ammonia release of ca. 20% have been observed. Similar impacts were measured at a high-solids digester pilot with up-stream thermal hydrolyses where the organic loading rate was increased by 25% using co-substrate. Dynamic simulations were used to validate the synergistic impact of co-substrate addition on sludge methanization, and an increase in hydrolysis rate from 1.5 d(-1) to 2.5 d(-1) was identified for simulating measured gas production rate. This study demonstrates co-digestion for maximizing synergy as a step towards energy efficiency and ultimately towards carbon neutrality.

  4. Modelling the Kinetics of Biogas Production from Mesophilic Anaerobic Co-Digestion of Cow Dung with Plantain Peels

    OpenAIRE

    Ganiyu Kayode Latinwo; Samuel Enahoro Agarry

    2015-01-01

    This work investigated the effect of plantain peels as co-substrate in the anaerobic digestion of cow dung for efficient and high biogas production. The biogas experiments were carried out in two different 5 L anaerobic digesters and incubated for 40 days at ambient mesophilic temperatures (28 oC to 34 °C). The results showed that co-digestion of cow dung with plantain peels as co-substrate reduced start-up time for biogas generation and increased biogas yield by 18% as compared to cow dung a...

  5. Economies of scale in biogas production and the significance of flexible regulation

    DEFF Research Database (Denmark)

    Nielsen, Lise Skovsgaard; Klinge Jacobsen, Henrik

    2017-01-01

    , and demonstrate that transport cost can be critical in relation to co-substrates. Further we compare the new Danish support for upgraded biogas with the traditional support for biogas being used in Combined Heat and Power production in relation to scale economies. We argue that economies of scale is facilitated...... by the new regulation providing similar support to upgraded biogas fed into the natural gas grid, however in order to keep transport costs low, we suggest that the biogas plants should be allowed to use and combine as many co-substrates as possible, respecting the sustainability criteria regarding energy...

  6. Degradation of Chlorinated Aliphatic Hydrocarbons by Methylosinus trichosporium OB3b Expressing Soluble Methane Monooxygenase

    NARCIS (Netherlands)

    Oldenhuis, Roelof; Vink, Ruud L.J.M.; Janssen, Dick B.; Witholt, Bernard

    1989-01-01

    Degradation of trichloroethylene (TCE) by the methanotrophic bacterium Methylosinus trichosporium OB3b was studied by using cells grown in continuous culture. TCE degradation was a strictly cometabolic process, requiring the presence of a cosubstrate, preferably formate, and oxygen. M. trichosporium

  7. Methane and hydrogen sulfide production during co-digestion of forage radish and dairy manure

    Science.gov (United States)

    Forage radish cover crops were investigated as a co-substrate to increase biogas production from dairy manure-based anaerobic digestion. Lab-scale batch digesters (300 mL) were operated under mesophilic conditions during two experiments. In the first experiment, the optimal co-digestion ratio for ...

  8. Intracellular PHB conversion in a type II methanotroph studied by 13 C NMR

    NARCIS (Netherlands)

    Vecherskaya, M.; Dijkema, C.; Stams, A.J.M.

    2001-01-01

    Poly-g-hydroxybutyrate (PHB) formation under aerobic conditions via incorporation of [13C-2]acetate as a cosubstrate and its intracellular degradation under anaerobic conditions in a Type II methanotroph was studied by 13C NMR. During PHB synthesis in the presence of labelled acetate, low levels of

  9. Effects of cysteine and acetaminophen on the syntheses of glutathione and adenosine 3'-phosphate 5'-phosphosulfate in isolated rat hepatocytes

    DEFF Research Database (Denmark)

    Dalhoff, K; Poulsen, H E

    1992-01-01

    The aim of the present study was to introduce and validate a radioactive tracer method in which adenosine 3'-phosphate 5'-phosphosulfate (PAPS) and glutathione (GSH) are measured simultaneously in isolated hepatocytes. PAPS and GSH are co-substrates in sulphation and GSH conjugation, and both are...

  10. Comparing environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy – A life cycle perspective

    NARCIS (Netherlands)

    Vries, de J.W.; Vinken, T.M.W.J.; Hamelin, L.; Boer, de I.J.M.

    2012-01-01

    The aim of this work was to assess the environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy, from a life cycle perspective. This included assessing environmental impacts and land use change emissions (LUC) required to replace used co-substrates for anaer

  11. Use of 5'-γ-ferrocenyl adenosine triphosphate (Fc-ATP) bioconjugates having poly(ethylene glycol) spacers in kinase-catalyzed phosphorylations.

    Science.gov (United States)

    Martić, Sanela; Rains, Meghan K; Freeman, Daniel; Kraatz, Heinz-Bernhard

    2011-08-17

    The 5'-γ-ferrocenyl adenosine triphosphate (Fc-ATP) bioconjugates (3 and 4), containing the poly(ethylene glycol) spacers, were synthesized and compared to a hydrophobic analogue as co-substrates for the following protein kinases: sarcoma related kinase (Src), cyclin-dependent kinase (CDK), casein kinase II (CK2α), and protein kinase A (PKA). Electrochemical kinase assays indicate that the hydrophobic Fc-ATP analogue was an optimal co-substrate for which K(M) values were determined to be in the 30-200 μM range, depending on the particular protein kinase. The luminescence kinase assay demonstrated the kinase utility for all Fc-ATP conjugates, which is in line with the electrochemical data. Moreover, Fc-ATP bioconjugates exhibit competitive behavior with respect to ATP. Relatively poor performance of the polar Fc-ATP bioconjugates as co-substrates for protein kinases was presumably due to the additional H-bonding and electrostatic interactions of the poly(ethylene glycol) linkers of Fc-ATP with the kinase catalytic site and the target peptides. Phosphorylation of the full-length protein, His-tagged pro-caspase-3, was demonstrated through Fc-phosphoamide transfer to the Ser residues of the surface-bound protein by electrochemical means. These results suggest that electrochemical detection of the peptide and protein Fc-phosphorylation via tailored Fc-ATP co-substrates may be useful for probing protein-protein interactions.

  12. Oxizymes for biotechnology

    NARCIS (Netherlands)

    Gygli, G.A.; Berkel, van W.J.H.

    2015-01-01

    Oxidation reactions with oxygen and peroxides are difficult to control in the artificial environment of man-made chemistry. This makes oxizymes, i.e. oxidative enzymes that use oxygen or peroxide as co-substrates, very valuable targets for the chemical and pharmaceutical industries. Additionally, gr

  13. Studies on the use of haloperoxidases in organic synthesis.

    NARCIS (Netherlands)

    Franssen, M.C.R.

    1987-01-01

    The subject of this thesis is the use of haloperoxidases in synthetic organic chemistry. Haloperoxidases are enzymes capable of halogenating a variety of organic compounds. They require hydrogen peroxide and halide ions as cosubstrates. The enzymes operate under mild conditions, compared to conventi

  14. Biogas production from ensiled meadow grass; effect of mechanical pretreatments and rapid determination of substrate biodegradability via physicochemical methods

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Angelidaki, Irini

    2015-01-01

    As the biogas sector is rapidly expanding, there is an increasing need in finding new alternative feedstock to biogas plants. Meadow grass can be a suitable co-substrate and if ensiled it can be supplied to biogas plants continuously throughout the year. Nevertheless, this substrate is quite reca...

  15. Conformational Flexibility of the C Terminus with Implications for Substrate Binding and Catalysis Revealed in a New Crystal Form of Deacetoxycephalosporin C Synthase

    NARCIS (Netherlands)

    Öster, Linda M.; Terwisscha van Scheltinga, Anke C.; Valegård, Karin; MacKenzie Hose, Alasdair; Dubus, Alain; Hajdu, Janos; Andersson, Inger

    2004-01-01

    Deacetoxycephalosporin C synthase (DAOCS) from Streptomyces clavuligerus catalyses the oxidative ring expansion of the penicillin nucleus into the nucleus of cephalosporins. The reaction requires dioxygen and 2-oxoglutarate as co-substrates to create a reactive iron–oxygen intermediate from a ferrou

  16. Mechanical Pretreatment to Increase the Bioenergy Yield for Full-scale Biogas Plants

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Angelidaki, Irini

    % compared to the untreated one. The digestion of meadow grass as an alternative co-substrate had positive impact on the energy yield of full-scale biogas reactors operating with cattle manure, pig manure or mixture of both. A preliminary analysis showed that the addition of meadow grass in a manure based...

  17. Rules for biocatalyst and reaction engineering to implement effective, NAD(P)H-dependent, whole cell bioreductions

    DEFF Research Database (Denmark)

    Kratzer, Regina; Woodley, John; Nidetzky, Bernd

    2015-01-01

    recycling of catalytic quantities, which is mostly accomplished by enzymatic oxidation of a cheap co-substrate. The coupled oxidoreduction can be either performed by free enzymes in solution or by whole cells. Reductase selection, the decision between cell-free and whole cell reduction system, coenzyme...

  18. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55

    NARCIS (Netherlands)

    Kotterman, M.

    1998-01-01

    Outline of this thesis
    In this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations,

  19. Comparing environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy – A life cycle perspective

    NARCIS (Netherlands)

    Vries, de J.W.; Vinken, T.M.W.J.; Hamelin, L.; Boer, de I.J.M.

    2012-01-01

    The aim of this work was to assess the environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy, from a life cycle perspective. This included assessing environmental impacts and land use change emissions (LUC) required to replace used co-substrates for

  20. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55

    NARCIS (Netherlands)

    Kotterman, M.

    1998-01-01

    Outline of this thesis
    In this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, whic

  1. Studies on the use of haloperoxidases in organic synthesis

    NARCIS (Netherlands)

    Franssen, M.C.R.

    1987-01-01

    The subject of this thesis is the use of haloperoxidases in synthetic organic chemistry. Haloperoxidases are enzymes capable of halogenating a variety of organic compounds. They require hydrogen peroxide and halide ions as cosubstrates. The enzymes operate under mild conditions, compared to

  2. Oxizymes for biotechnology

    NARCIS (Netherlands)

    Gygli, G.A.; Berkel, van W.J.H.

    2015-01-01

    Oxidation reactions with oxygen and peroxides are difficult to control in the artificial environment of man-made chemistry. This makes oxizymes, i.e. oxidative enzymes that use oxygen or peroxide as co-substrates, very valuable targets for the chemical and pharmaceutical industries. Additionally, gr

  3. Environmental Consequences of Future Biogas Technologies based on Separated Slurry

    DEFF Research Database (Denmark)

    Hamelin, Lorie; Wesnæs, Marianne; Wenzel, Henrik

    2011-01-01

    This consequential life cycle assessment study highlights the key environmental aspects of producing biogas from separated pig and cow slurry, a relatively new but probable scenario for future biogas production, as it avoids the reliance on constrained carbon cosubstrates. Three scenarios involvi...

  4. Optimization of the Co-Digestion of Catch Crops with Manure Using a Central Composite Design and Reactor Operation

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Ahring, Birgitte Kiær; Uellendahl, Hinrich

    2015-01-01

    This study investigates the effect of catch crops as co-substrate on manure-based anaerobic digestion. Batch experiments were carried out for two catch crops, namely Italian ryegrass (IR) and oil seed radish (OSR), in co-digestion with manure. Methane yields in the range of 271–558 and 216–361 ml...

  5. Evaluating and modeling biogas production from municipal fat, oil, and grease and synthetic kitchen waste in anaerobic co-digestions.

    Science.gov (United States)

    Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

    2011-10-01

    The feasibility of using synthetic kitchen waste (KW) and fat, oil, and grease (FOG) as co-substrates in the anaerobic digestion of waste activated sludge (WAS) was investigated using two series of biochemical methane potential (BMP) tests. Ranges of ideal substrate to inoculum (S/I) ratio were determined for the FOG (0.25-0.75) and KW (0.80-1.26) as single substrates in the first experiment. The second experiment, which estimated the methane production performances of FOG and KW as co-substrates for WAS co-digestion, was conducted based on the optimal parameters selected from the results of the first experiment. Results indicated that co-digestions with FOG and KW enhanced methane production from 117±2.02 mL/gTVS (with only WAS) to 418±13.7 mL/gTVS and 324±4.11 mL/gTVS, respectively. FOG exhibited more biogas production than KW as co-substrate. Non-linear regression results showed that co-substrate addition shortened the lag phases of organic biodegradation from 81.8 (with only WAS) to 28.3 h with FOG and 3.90 h with KW.

  6. Grass as a C booster for manure-biogas in Estonia

    DEFF Research Database (Denmark)

    Pehme, Sirli; Hamelin, Lorie; Veromann, Eve

    2014-01-01

    The aim of this study was to assess the environmental consequences of using grass (from both unused and cultivated boreal grasslands) as a co-substrate to dairy cow manure for biogas production. Environmental impact categories assessed were global warming, acidification and nutrient enrichment (d...

  7. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Kotterman, M.J.J.

    1998-01-01

    Outline of this thesisIn this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, which influenced the oxidation of the PAH compound anthra

  8. Central key project `Biotechnology`. Supplementary report. 2nd project phase (3/95 through 12/95); Zentrales Schwerpunktprojekt Bioverfahrenstechnik. Ergaenzungsbericht 2. Foerderphase (3/95 bis 12/95)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The report describes the activities of the three sections of the key project `Biotechnology`: Biological systems, e.g. environmental biotechnology, enzyme reactions; protein engineering, fermentation problems of secondary metabolites, tetrachloroethylene degradation, stereoselective synthesis; process engineering, i.e. supercritical solvents, enzyme-catalysed reactions, bipolar membrane technology, membrane separation processes, anaerobic processes; information engineering, i.e. morphology recording, process control. Separate abstracts are available in this database for two articles of this report. (SR) [Deutsch] Dargestellt werden die Taetigkeiten der verschiedenen Arbeitsbereiche des Schwerpunktprojektes Biotechnologie. Es handelt sich hierbei um die drei Projektbereiche: Biologische Systeme unter anderem mit den Themen Umweltbiotechnologie, Enzymreaktionen, Protein-Engineering, Fermentationsprobleme bei sekundaeren Metaboliten, Tetrachlorethylen-Abbau, Stereoselektive Synthese; des weiteren der Projektbereich Verfahrenstechnik unter anderem mit den Themen Ueberkritische Loesungsmittel, Enzymkatalysierte Reaktionen, Bipolare Membrantechnik, Membrantrennverfahren, Anaerobprozesse; als letztes der Projektbereich Informationstechnik mit den Themen Morphologieerfassung, Prozessfuehrung. (SR)

  9. Disintegration of sewage sludge - an economically efficient alternative?; Desintegration von Klaerschlamm - eine wirtschaftliche Alternative?

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, K. [ULTRAWAVES Wasser- und Umwelttechnologien GmbH, Hamburg (Germany); Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

    2003-07-01

    The solid fraction of biological sewage sludge is mostly comprised of organic cell substance. Thermal, chemical or mechanical treatment will release organic compounds from the cells for better biodegradation. This contribution discusses the applicability of ultrasonic treatment for disintegration of sludge cells. For this, extensive research was carried out at the Technical University of Hamburg-Harburg. (orig.) [German] Die Feststoffe biologischer Klaerschlaemme bestehen zu grossem Teil aus organischer Zellsubstanz. Durch einen thermischen, chemischen oder mechanischen Aufschluss des Zellmaterials koennen organische Verbindungen aus dem Zellinneren freigesetzt werden und sind damit dem nachfolgenden biologischen Abbau besser zugaenglich. Den Ueberblick ueber die verschiedenen Desintegrationsverfahren gibt ein separater Beitrag dieser Veranstaltung. Dieses Paper beschaeftigt sich mit dem Einsatz der Ultraschallbehandlung zur Desintegration von Schlammzellen. Zu diesem Verfahren wurden umfangreiche Erkenntnisse in langjaehrigen Forschungsarbeiten an der Technischen Universitaet Hamburg-Harburg gesammelt. (orig.)

  10. Bioactivation of 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) by human NAD(P)H quinone oxidoreductase 2: a novel co-substrate-mediated antitumor prodrug therapy.

    Science.gov (United States)

    Knox, R J; Jenkins, T C; Hobbs, S M; Chen, S; Melton, R G; Burke, P J

    2000-08-01

    A novel prodrug activation system, endogenous in human tumor cells, is described. A latent enzyme-prodrug system is switched on by a simple synthetic, small molecule co-substrate. This ternary system is inactive if any one of the components is absent. CB 1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide] is an antitumor prodrug that is activated in certain rat tumors via its 4-hydroxylamine derivative to a potent bifunctional alkylating agent. However, human tumor cells are resistant to CB 1954 because they are unable to catalyze this bioactivation efficiently. A human enzyme has been discovered that can activate CB 1954, and it has been shown to be commonly present in human tumor cells. The enzyme is NQO2 [NAD(P)H quinone oxidoreductase 2], but its activity is normally latent, and a nonbiogenic co-substrate such as NRH [nicotinamide riboside (reduced)] is required for enzymatic activity. There is a very large (100-3000-fold) increase in CB 1954 cytotoxicity toward either NQO2-transfected rodent or nontransfected human tumor cell lines in the presence of NRH. Other reduced pyridinium compounds can also act as co-substrates for NQO2. Thus, the simplest quaternary salt of nicotinamide, 1-methyl-3-carboxamidopyridinium iodide, was a co-substrate for NQO2 when reduced to the corresponding 1,4-dihydropyridine derivative. Increased chain length and/or alkyl load at the 1-position of the dihydropyridine ring improved specific activity, and compounds more active than NRH were found. However, little activity was seen with either the 1-benzyl or 1-(2-phenylethyl) derivatives. A negatively charged substituent at the 3-position of the reduced pyridine ring also negated the ability of these compounds to act as cosubstrates for NQO2. In particular, 1-carbamoylmethyl-3-carbamoyl-1,4dihydropyridine was shown to be a co-substrate for NQO2 with greater stability than NRH, with the ability to enter cells and potentiate the cytotoxicity of CB 1954. Furthermore, this agent is synthetically

  11. Kultivierungsverfahren für Bakterien

    Science.gov (United States)

    Messelhäußer, Ute

    Lange Zeit war die Isolierung bakterieller pathogener Mikroorganismen mithilfe von entsprechenden Nährmedien die einzige Möglichkeit zum Nachweis der Erreger in Lebensmittel-, Human- und Veterinärproben. Diese Vorgehensweise wurde Mitte des 19. Jahrhunderts entwickelt. Damals gehörte Louis Pasteur zu den ersten Mikrobiologen, die es für notwendig erachteten, Krankheitserreger auch außerhalb des menschlichen Körpers kultivieren zu können und entwickelte deshalb 1861 die erste flüssige Anreicherungsbouillon [7]. Er legte damit einen der Grundsteine für die heutige mikrobiologische Diagnostik und alle weiteren, darauf aufbauenden Disziplinen. Grundlage der modernen bakteriellen Lebensmittelsuntersuchung sind, im Gegensatz zur viralen Diagnostik, nach wie vor entsprechende Anreicherungsschritte. Vor allem die oftmals sehr geringe Infektionsdosis der unterschiedlichen lebensmittelrelevanten Infektionserreger bedingt eine Nulltoleranz derartiger Mikroorganismen in verzehrfertigen Lebensmitteln und somit die Notwendigkeit einer Kultivierung mittels unterschiedlicher Anreicherungsmethoden vor dem Einsatz molekularer Nachweisverfahren, wie z. B. PCR und Real-Time-PCR. Nach den derzeitigen gesetzlichen Vorgaben ist zusätzlich zu dem molekularbiologischen Nachweis von Infektions- und Intoxikationserregern in der Lebensmittelanalytik der kulturelle Keimnachweis zwingend notwendig. Molekulare Nachweisverfahren können somit entweder als Screeningmethoden für einen schnellen und hohen Probendurchsatz oder nach entsprechenden Kultivierungsschritten zur Bestätigung bestimmter genetischer Eigenschaften von Isolaten herangezogen werden [12].

  12. Biological and chemical development of mining lakes. Status report 1998/1999. Data acquisition, methods, trends; Biologische und chemische Entwicklung von Bergbaurestseen. Statusbericht 1998/1999. Bestandsaufnahme, Methoden und Entwicklungen

    Energy Technology Data Exchange (ETDEWEB)

    Friese, K.; Tuempling, W. von (eds.)

    2000-07-01

    Acidification of mining lakes in central Germany and the Lausitz was investigated for three aspects: 1.) biological dynamics and material effects on plancton abundance and variety; 2.) Chemical and microbiological interactions between sediments influenced by mining (authochthone, allochthone) and water phase 3. 3.) Limnological and hydrochemical development of water systems in abandoned mining areas with a view to environmental quality and/or utilisation. The following objects were investigated. a) Goitsche open-cast mine (Bitterfeld district); b) Lake 111 (Koyne/Pllessa district), - Lakes 107, 117 (Koyne/Plessa district), Lake b (Schlabendorf-Nord district). [German] Kernproblem in den Braunkohlengebieten der neuen Bundeslaender ist die Versauerung von Bergbauseen. Die Bearbeitung des Verbundprojektes konzentriert sich in den Bergbaufolgelandschaften der Regionen Mitteldeutschland und Lausitz auf bergbaulich gestoerte und in Veraenderung befindliche Oberflaechenwasser-Systeme. Arbeitziele sind 1.) die Vertiefung der Kenntnisse zur biologischen Dynamik und zum stofflichen Einfluss auf die Diversitaet und Abundanz von Plankton in sauren Bergbauseen 2) Untersuchungen zu spezifischen Wechselwirkungen (chemisch, mikrobiologisch) zwischen bergbaulich beeinflussten Sedimenten (autochthon, allochthon) und der Wasserphase 3. Betrachtungen der limnologischen und hydrochemischen Entwicklung der Wassersysteme in Bergbaufolgelandschaften hinsichtlich Umweltqualitaetszielen und/oder Nutzungszielen. Im Rahmen des Verbundprojektes werden von den Sektionen Gewaesserforschung, Hydrogeologie, Analytik, Bodenforschung und Umweltmikrobiologie in Mitteldeutschland und der Lausitz folgende Objekte bearbeitet: a) Tagebaukomplex Goitsche (Bitterfelder Revier) und b) Restloch 111 (Revier Koyne/Plessa), - Restloch 107, 117 (Revier Koyne/Plessa), - Restloch B (Revier Schlabendorf-Nord). (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-01

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

  14. Microbial contamination of mobile phones in a health care setting in Alexandria, Egypt.

    Science.gov (United States)

    Selim, Heba Sayed; Abaza, Amani Farouk

    2015-01-01

    Zielsetzung: Es sollte die mikrobielle Kontamination von Mobiltelefonen in einer universitären Gesundheitseinrichtung untersucht werden.Methode: Abstrichproben wurden von 40 Mobiltelefonen von Patienten und Mitarbeitern im Universitätskrankenhaus in Alexandria entnommen. Die mikrobiologische Analyse wurde im mikrobiologischen Labor des Instituts für Public Health durchgeführt. Die Quantifizierung erfolgte sowohl durch direkte Ausbringung auf die Platte als auch durch Anlage von Subkulturen zur Differenzierung. Methicillin-resistente Staphylococcus aureus (MRSA) wurden mittels Plättchendiffusionsmethode nach Bauer und Kirby identifiziert. Isolierte Gram-negative Organismen wurden auf Vorkommen von ESBL-Bildung mittels der Doppeldiffusionsmethode gemäß Empfehlung des Clinical and Laboratory Standards Institute untersucht.Ergebnisse: Alle untersuchten Mobiltelefone waren entweder mit einer oder mehreren bakteriellen Arten kontaminiert. Am häufigsten wurden MRSA (53%) und Koagulase-negative Staphylokokken (50%) nachgewiesen. Als mittlere Anzahl von KbE ergaben sich 357 KbE mit einem Median von130 KbE/ml pro Mobiltelefon im Plattengussverfahren. Die korrespondierenden Werte betrugen 2.192 bzw. 1.720 KbE/Mobiltelefon im Direktausstrich.Schlussfolgerung: Mobiltelefone stellen ein Risiko in Gesundheitseinrichtungen zur Weiterverbreitung nosokomialer Pathogen einschließlich MRSA dar. Auf der Oberfläche von Mobiltelefonen kann die mikrobielle Kontamination methodisch einfach nachgewiesen werden.

  15. Utilisation potential of products of microbial coal liquefaction. Final report; Verwertungspotential der Produkte der mikrobiellen Kohleverfluessigung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Koepsel, R.; Schmiers, H.; Grosse, S.; Weber, A.

    2002-07-01

    Ever since the discovery in the 1980s that microorganisms are capable of converting coal into soluble products research groups all over the world have been exploring the bioconversion of coal. It was at an advance stage of the present integrated project, which initially only involved microbiology research groups, that the need for a chemical working group with knowledge and experience in the area of coal chemistry and structural analysis of coal was recognised. The task of the chemical working group was to provide knowledge on the chemical nature of bioconversion products and the chemical processes of coal bioconversion. This involved identifying structural changes occurring in the feed coal as well as in its constituent humic acids and macromolecular matrix as a result of the activity of coal degrading microorganisms. [German] Nachdem Anfang der achtziger Jahre entdeckt wurde, dass sich Kohlen durch Mikroorganismen in loesliche Produkte ueberfuehren lassen, agieren weltweit Forschergruppen auf dem Gebiet der Biokonversion von Kohle. In einem fortgeschrittenen Bearbeitungsstadium des Verbundprojektes, an dem zunaechst nur mikrobiologische Arbeitsgruppen beteiligt waren, wurde die Notwendigkeit erkannt, eine chemische Arbeitsgruppe mit Kenntnissen und Erfahrungen auf den Gebieten der Kohlechemie und der Strukturanalytik von Kohlen zu integrieren. Aufgabenstellung der chemischen Arbeitsgruppe war und ist es, Erkenntnisse ueber die chemische Natur der Biokonversionsprodukte und die chemischen Ablaeufe der mikrobiellen Kohlekonversion bereitstellen. Die Aufgabenstellung umfasst die Aufklaerung der strukturellen Veraenderung der Einsatzkohle sowie ihrer Komponenten Huminsaeuren und makromolekulare Matrix durch die Einwirkung kohleabbauender Mikroorganismen. (orig.)

  16. Diffusion of the biogas technology into Switzerland: a GIS-based multiagent simulation; Diffusion der Biogastechnologie in der Schweiz: eine GIS-basierte Multiagenten-Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Christian [Campana und Schott Realisierungsmanagement Schweiz AG, Zuerich (Switzerland); Madlener, Reinhard [Lehrstuhl fuer Wirtschaftswissenschaften insb. Energieoekonomik, Inst. for Future Energy Consumer Needs and Behavior (FCN), Fakultaet fuer Wirtschaftswissenschaften/E.ON Energy Research Center, RWTH Aachen (Germany)

    2008-12-15

    In this article we introduce a GIS-based multi-agent simulation model. It is used to study the spatial diffusion dynamics of agricultural biogas plants in Switzerland, which lags markedly behind those in the neighboring countries Austria and Germany. The investigation concentrates in particular on the impacts of economic factors and of locally available resources on the diffusion process. The model considers three different types of plants (100 kW{sub el}, 200 kW{sub el}, 1 MW{sub el}). The results show that feed-in tariffs, cosubstrate prices and the revenues from heat sales are critical parameters. They indicate further that the present promotion policy fosters smaller plants, whereas larger plants are preferred only in few areas with high substrate densities. Finally, we find evidence that increased heat sales can significantly raise diffusion dynamics, and that the higher feed-in tariffs planned in Switzerland could actually overcompensate deteriorating cosubstrate prices. (orig.)

  17. Diplogelasinospora grovesii IMI 171018 immobilized in polyurethane foam. An efficient biocatalyst for stereoselective reduction of ketones.

    Science.gov (United States)

    Quezada, M A; Carballeira, J D; Sinisterra, J V

    2012-05-01

    Diplogelasinospora grovesii has been reported as a very active biocatalyst in the reduction of ketones. Along the text, the properties of this filamentous fungus as an immobilized catalyst are described. For this purpose, several immobilization supports as agar and polyurethane foam were tested. Experimental assays were also performed to test different co-substrates for the regeneration of the required enzyme cofactor. The fungus immobilized in polyurethane foam lead to the most stable and active catalyst. This derivative, using i-PrOH as co-substrate, could be reused at least 18 times without appreciable activity loss (>90% activity remains). Kinetic runs experiments shown that the reduction of cyclohexanone, selected as model substrate, followed a pseudo-first kinetic order and that the rate controlling step was the mass transfer through the cell wall. The deactivation kinetic constants were also determined. The reduction of different chiral ketones showed that the ketone reductase activity followed the Prelog's rule.

  18. ALKBH7 Variant Related to Prostate Cancer Exhibits Altered Substrate Binding

    Science.gov (United States)

    Müller, Tina A.; Podolsky, Robert H.; Dyson, Gregory; Cisneros, Gerardo Andrés

    2017-01-01

    The search for prostate cancer biomarkers has received increased attention and several DNA repair related enzymes have been linked to this dysfunction. Here we report a targeted search for single nucleotide polymorphisms (SNPs) and functional impact characterization of human ALKBH family dioxygenases related to prostate cancer. Our results uncovered a SNP of ALKBH7, rs7540, which is associated with prostate cancer disease in a statistically significantly manner in two separate cohorts, and maintained in African American men. Comparisons of molecular dynamics (MD) simulations on the wild-type and variant protein structures indicate that the resulting alteration in the enzyme induces a significant structural change that reduces ALKBH7’s ability to bind its cosubstrate. Experimental spectroscopy studies with purified proteins validate our MD predictions and corroborate the conclusion that this cancer-associated mutation affects productive cosubstrate binding in ALKBH7. PMID:28231280

  19. Deterioration of organic packing materials commonly used in air biofiltration: effect of VOC-packing interactions.

    Science.gov (United States)

    Lebrero, Raquel; Estrada, José M; Muñoz, Raúl; Quijano, Guillermo

    2014-05-01

    The abiotic deterioration of three conventional organic packing materials used in biofiltration (compost, wood bark and Macadamia nutshells) caused by their interaction with toluene (used as a model volatile organic compound) was here studied. The deterioration of the materials was evaluated in terms of structural damage, release of co-substrates and increase of the packing biodegradability. After 21 days of exposure to toluene, all packing materials released co-substrates able to support microbial growth, which were not released by the control materials not exposed to toluene. Likewise, the exposure to toluene increased the packing material biodegradability by 26% in wood bark, 20% in compost and 17% in Macadamia nutshells. Finally, scanning electron microscopy analysis confirmed the deterioration in the structure of the packing materials evaluated due to the exposure to toluene, Macadamia nutshells being the material with the highest resistance to volatile organic compound attack.

  20. Anaerobic modeling for improving synergy and robustness of a manure co-digestion process

    DEFF Research Database (Denmark)

    Lima, D. M. F.; Rodrigues, J. A. D.; Boe, Kanokwan

    2016-01-01

    Biogas production is becoming increasingly important in the environmental area because, besides treating wastewaters, it also generates energy. Co-digestion has become more and more powerful since it is possible, with the use of abundant and cheap substrates, to dilute the inhibitory effects...... of various other substrates, making the process of anaerobic digestion more efficient and stable. Biogas process modelling describes the kinetics and stoichiometry of different steps in the anaerobic digestion process. This mathematical modelling provides an understanding of the processes and interactions...... occurring inside the biogas system. The present work investigated the interactions between different simple co-substrates (carbohydrate, lipid and protein) and real co-substrates (corn silage, fodder beet, grass and wheat straw) under co-digestion with manure, in order to verify synergetic effects...

  1. ANAEROBIC MODELING FOR IMPROVING SYNERGY AND ROBUSTNESS OF A MANURE CO-DIGESTION PROCESS

    Directory of Open Access Journals (Sweden)

    D. M. F. Lima

    Full Text Available Abstract Biogas production is becoming increasingly important in the environmental area because, besides treating wastewaters, it also generates energy. Co-digestion has become more and more powerful since it is possible, with the use of abundant and cheap substrates, to dilute the inhibitory effects of various other substrates, making the process of anaerobic digestion more efficient and stable. Biogas process modelling describes the kinetics and stoichiometry of different steps in the anaerobic digestion process. This mathematical modelling provides an understanding of the processes and interactions occurring inside the biogas system. The present work investigated the interactions between different simple co-substrates (carbohydrate, lipid and protein and real co-substrates (corn silage, fodder beet, grass and wheat straw under co-digestion with manure, in order to verify synergetic effects. Subsequently, some experiments were reproduced, in order to evaluate the synergy obtained in the previous simulation and validate the model.

  2. An Approximate Analytical Method for the Evaluation of the Concentrations and Current for Hybrid Enzyme Biosensor

    OpenAIRE

    2013-01-01

    Mathematical modeling of amperometric biosensor with cyclic reaction is discussed. Analytical expressions pertaining to the concentration of substrate, cosubstrate, reducing agent and medial product and current for hybrid enzyme biosensor are obtained in terms of Thiele module and saturation parameters. In this paper, a powerful analytical method, called homotopy analysis method (HAM) is used to solve the system of nonlinear differential equations. Furthermore, in this work the numerical simu...

  3. Two-stage digestion of renewable raw materials. Applying bioleaching for utilizing grass silage; Zweiphasige Vergaerung nachwachsender Rohstoffe. Einsatz des Bioleaching-Verfahrens zur Verwertung von Grassilage

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H. [Hohenheim Univ., Stuttgart (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen; Jungbluth, T. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Agrartechnik

    2007-07-01

    Currently renewable raw materials are being used in full scale biogas plants as co-substrates. Using grass silage frequently caused technical problems till now. Within the framework of this project, a process to digest grass silage as a single substrate is being developed. An intermittently operating two-stage process is used. As far as the degree of degradation and methane yields are concerned, good and promising results have been achieved. (orig.)

  4. Remediation of Perfluoroalkyl Contaminated Aquifers Using an In-situ Two-layer Barrier: Laboratory Batch and Column Study

    Science.gov (United States)

    2013-04-01

    Environmental Science & Technology 42(21), 8057-8063. Cheng, J., et al. (2010) Sonochemical Degradation of Perfluorooctane Sulfonate (PFOS) and...Perfluorooctanoate (PFOA) in Groundwater: Kinetic Effects of Matrix Inorganics. Environmental Science & Technology 44(1), 445-450. Colosi, L.M., et al...Removal of a Polychlorinated Biphenyl Using Natural Organic Matter as the Sole Cosubstrate. Environmental Science & Technology 41(3), 891-896

  5. Anaerobic co-digestion of cork based oil sorbent and cow manure or sludge

    OpenAIRE

    Cavaleiro, A. J.; Neves, T. M.; Guedes, Ana P.; Alves, M.M.; Pinto, P.; Silva, S.P.; Sousa, D.Z.

    2015-01-01

    Cork, a material with great economic, social and environmental importance in Portugal, is also a good oil sorbent that can be used in the remediation of oil spills. The oil-impregnated cork can be easily removed, but requires further treatment. In the case of vegetable oil spills, anaerobic digestion may be a potential solution. This study aims to evaluate the effect of adding cork contaminated with sunflower oil as co-substrate in anaerobic digestion processes. Biodegradability assays were p...

  6. Anaerobic digestion of different organic wastes for biogas production and its operational control performed by the modified ADM1.

    Science.gov (United States)

    Zhou, Haidong; Li, Han; Wang, Fengfei

    2012-01-01

    Anaerobic digestion (AD) of different organic wastes for biogas production under variable operating conditions was simulated with a steady-state implementation of the modified IWA Anaerobic Digestion Model No. 1 (ADM1), and an input-output feedback control system using the model as a test platform was developed. The main aim of this study was to compare the characteristics of organic wastes in the AD processes and manage to keep the processes stable based on the results of simulation. The two important operating factors, solid retention time (SRT) and organic loading rate (OLR) (or the ratio of input flows for co-digestion), were investigated. Anaerobic digestion of biowaste was characterized with lower biogas production and instability of the processes, especially at OLR 2.5 kgCOD/m(3)·d or more, although longer SRT could increase the biogas production. Moreover, the co-substrate composed of biowaste and corn silage would lead to instability of the processes and much lower biogas production. Biowaste was, however, preferable to be co-digested with manures of living stock or sewage sludge. Manure could contribute to the stability of the AD processes, and its co-substrates with organic wastes rich in carbohydrates such as biowaste and corn silage would improve the biogas production and the proportion of methane. Longer SRTs would improve the biogas production from manure as well as its co-substrates except the co-substrate with biowaste as the production was not distinctly raised. The test of the developed input-output feedback control system showed that the control system could reject a realistic set of random disturbances and keep the AD processes stable under the desired operational conditions with a minimal use of measurement facilities.

  7. Metabolism of mono- and dihalogenated C1 and C2 compounds by Xanthobacter autotrophicus growing on 1,2-dichloroethane

    OpenAIRE

    Torz, Maciej; Wietzes, Piet; Beschkov, Venko; Janssen, Dick B.

    2007-01-01

    The conversion of and toxic effects exerted by several mono- and dihalogenated C1 and C2 compounds on cultures of Xanthobacter autotrophicus GJ10 growing on 1,2-dichloroethane were investigated. Bromochloromethane, dibromomethane and 1-bromo-2-chloroethane were utilized by strain GJ10 in batch culture as a cosubstrate and sole carbon source. The rate of degradation of dihalomethanes by whole cells was lower than that of 1,2-dichloroethane, but a significant increase of the rate of dihalometha...

  8. Comment on "Synergistic co-digestion of solid-organic-waste and municipal-sewage-sludge: 1 plus 1 equals more than 2 in terms of biogas production and solids reduction" [Water Research 87, 416-423].

    Science.gov (United States)

    Insam, Heribert; Markt, Rudolf

    2016-05-15

    Co-digestion of organic waste and sewage sludge enhances biogas production and reduces the mass of remaining solids. This phenomenon of enhanced organic matter decomposition by adding labile substrate is known from other habitats like soils and sediments where it is called priming effect. It is thus suggested to adopt the term priming effect also in environmental biotechnology, and in particular for biomethanisation of wastewater sludges by the addition of energy-rich co-substrates.

  9. Anaerobic co-digestion of aquatic flora and quinoa with manures from Bolivian Altiplano.

    Science.gov (United States)

    Alvarez, René; Lidén, Gunnar

    2008-01-01

    Quinoa stalk (Chenopodium quinoa Willd.) from agricultural crop residue, totora (Schoenoplectus tatora) and o-macrophytes (aquatic flora) from Lake Titicaca (on the Bolivian Altiplano) were studied in a wet anaerobic co-digestion process together with manure from llama, cow and sheep. Anaerobic semi-continuous experiments were performed in (10) 2-l reactors at a temperature of 25 degrees C with 30 days of hydraulic retention time (HRT) and an organic loading rate (OLR) of 1.8 kg VS m(-3) d(-1). Totora was found to be the best co-substrate. In mixture ratios of 1:1 (VS basis), it increased the biogas productivity by 130% for llama manure, 60% for cow manure, and 40% for sheep manure. It was possible to use up to 58% (VS basis) of totora in the substrate. Higher concentrations (including pure totora) could not be digested, as that caused acidification problems similar to those caused by other lignocellulosic materials. When quinoa and o-macrophytes were used as co-substrates, the increase in biogas productivity was slightly less. However, these co-substrates did not cause any operational problems. An additional advantage of quinoa and o-macrophytes was that they could be used in any proportion (even in pure form) without causing any destabilization problems in the anaerobic digestion process.

  10. Possible roles of transglutaminases in molecular mechanisms responsible for human neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Nicola Gaetano Gatta

    2016-11-01

    Full Text Available Transglutaminases are a family of Ca2+-dependent enzymes which catalyze post-translational modifications of proteins. The main activity of these enzymes is the cross-linking of glutaminyl residues of a protein/peptide substrate to lysyl residues of a protein/peptide co-substrate. In addition to lysyl residues, other second nucleophilic co-substrates may include monoamines or polyamines (to form mono- or bi-substituted/crosslinked adducts or –OH groups (to form ester linkages. In absence of co-substrates, the nucleophile may be water, resulting in the net deamidation of the glutaminyl residue. Transglutaminase activity has been suggested to be involved in molecular mechanisms responsible for both physiological or pathological processes. In particular, transglutaminase activity has been shown to be responsible for human autoimmune diseases, Celiac Disease is just one of them. Interestingly, neurodegenerative diseases, such as Alzheimer’s Disease, Parkinson’s Disease, supranuclear palsy, Huntington’s Disease and other polyglutamine diseases, are characterized in part by aberrant cerebral transglutaminase activity and by increased cross-linked proteins in affected brains. This review describes the possible molecular mechanisms by which these enzymes could be responsible for such diseases and the possible use of transglutaminase inhibitors for patients with diseases characterized by aberrant transglutaminase activity.

  11. Effects of carbon and nitrogen supplementation on lignin and cellulose decomposition by a Streptomyces.

    Science.gov (United States)

    Barder, M J; Crawford, D L

    1981-08-01

    Effects of nitrogen source and concentration and organic carbon cosubstrates on lignin and cellulose degradation by Streptomyces badius strain 252 were examined using 14C-labeled substrates prepared from Pseudotsuga menziesii twigs. As compared with white-rot fungi, which do not degrade lignin in the absence of a readily metabolizable carbon cosubstrate, degradation of a milled-wood lignin occurred in a minimal medium, although degradation by S. badius was greatly enhanced when organic nitrogen and an organic carbon cosubstrate were added to the medium. Lignin degradation was greatest in the presence of high levels of organic nitrogen. Further enhancement of lignin and cellulose degradation occurred in a medium containing organic nitrogen supplemented with low levels of NO3-. The specific effects of inorganic nitrogen on lignocellulose degradation by S. badius in an otherwise optimal medium included both enhancement and inhibition of lignin or cellulose degradation depending on the source and concentration of inorganic nitrogen used. These effects were distinctly different from those observed with white-rot fungi and were shown to be specific ion effects on polymer degradation and not simply a salt concentration effect on cellular growth.

  12. Simultaneous production of lactobionic and gluconic acid in cheese whey/glucose co-fermentation by Pseudomonas taetrolens.

    Science.gov (United States)

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-11-01

    Substrate versatility of Pseudomonas taetrolens was evaluated for the first time in a co-fermentation system combining cheese whey and glucose, glycerol or lactose as co-substrates. Results showed that P. taetrolens displayed different production patterns depending on the co-substrate supplied. Whereas the presence of glucose led to a simultaneous co-production of lactobionic (78g/L) and gluconic acid (8.8g/L), lactose feeding stimulated the overproduction of lactobionic acid from whey with a high specific productivity (1.4g/gh) and yield (100%). Co-substrate supply of glycerol conversely led to reduced lactobionic acid yield (82%) but higher cell densities (1.8g/L), channelling the carbon source towards cell growth and maintenance. Higher carbon availability impaired the metabolic activity as well as membrane integrity, whereas lactose feeding improved the cellular functionality of P. taetrolens. Insights into these mixed carbon source strategies open up the possibility of co-producing lactobionic and gluconic acid into an integrated single-cell biorefinery.

  13. Comparing the inhibitory thresholds of dairy manure co-digesters after prolonged acclimation periods: Part 2--correlations between microbiomes and environment.

    Science.gov (United States)

    Regueiro, Leticia; Spirito, Catherine M; Usack, Joseph G; Hospodsky, Denina; Werner, Jeffrey J; Angenent, Largus T

    2015-12-15

    Here, we studied the microbiome succession and time-scale variability of four mesophilic anaerobic reactors in a co-digestion study with the objective to find links between changing environmental conditions and the microbiome composition. The changing environmental conditions were ensured by gradual increases in loading rates and mixing ratios of three co-substrates with a constant manure-feeding scheme during an operating period longer than 900 days. Each co-substrate (i.e., alkaline hydrolysate, food waste, and glycerol) was co-digested separately. High throughput 16S rRNA gene sequencing was used to examine the microbiome succession. The alkaline hydrolysate reactor microbiome shifted and adapted to high concentrations of free ammonia, total volatile fatty acids, and potassium to maintain its function. The addition of food waste and glycerol as co-substrates also led to microbiome changes, but to a lesser extent, especially in the case of the glycerol reactor microbiome. The divergence of the food waste reactor microbiome was primarily linked to increasing free ammonia levels in the reactor; though, these levels remained below previously reported inhibitory levels for acclimated biomass. The glycerol reactor microbiome succession included an increase in Syntrophomonadaceae family members, which have previously been linked to long-chain fatty acid degradation. The glycerol reactor exhibited rapid failure and limited adaptation at the end of the study.

  14. Sophorolipids: improvement of the selective production by Starmerella bombicola through the design of nutritional requirements.

    Science.gov (United States)

    Ribeiro, Isabel A; Bronze, M Rosário; Castro, Matilde F; Ribeiro, Maria H L

    2013-03-01

    Microtiter plates were used as minireactors to study Starmerella bombicola growth and sophorolipid (SL) production. Compositional analysis of SL mixtures by liquid chromatography with electrospray ionization tandem mass spectrometry showed similar results on SLs produced using the laboratory scale (shake flask) and the microscale (24-well microtiter plates (MTP)) approach. MTP suitability on SL production was proven, being this approach, especially advantageous on SL screening. Several hydrophilic carbon sources, hydrophobic co-substrates and nitrogen sources were supplied to culture media, and their influence on SL production was evaluated. The selection of specific hydrophobic co-substrate and nitrogen sources influenced the ratio acidic/lactonic SLs. In fact, it was observed that the production of acidic C18:1 diacetylated hydroxy fatty acid SLs was favoured when culture media was supplied with avocado, argan, sweet almond and jojoba oil or when NaNO(3) was supplied instead of urea. This last case was observed after 144 h of cultivation. A new SL, lactonic C18:3 hydroxy fatty acid diacetylated SL, was detected when borage and onagra oils were used individually as co-substrates. Overall results indicated the potential of the selective production of different and new sophorolipids by Starmerella bombicola based on the selection of carbon and nitrogen sources to culture media.

  15. Enhancement of 4-chlorophenol biodegradation using glucose

    Energy Technology Data Exchange (ETDEWEB)

    Tarighian, Alireza; Hill, Gordon; Headley, John [Division of Environmental Engineering, University of Saskatchewan, 105 Maintenance Road, S7N 5C5, Saskatoon, SK (Canada); Pedras, Soledad [Department of Chemistry, University of Saskatchewan, 110 Science Place, S7N 5C9, Saskatoon, SK (Canada)

    2003-03-01

    Toxic, xenobiotic chemicals present challenging problems for the environment since they are normally resistant to biodegradation. Sometimes it is possible to induce biodegradation activity by the use of growth cosubstrates. In this study, pure solutions and binary mixtures of glucose, phenol and 4-chlorophenol have been metabolized in batch cultures by a pure strain of Pseudomonas putida. Following a lag period during which slow growth and low production of biomass occurred, phenol was metabolized according to the Monod model. Glucose was also metabolized according to the Monod model but exponential growth commenced immediately after inoculation with no noticeable lag phase. Biokinetic behavior for growth on a mixture of phenol and glucose paralleled the behavior on individual substrates with simultaneous consumption of both substrates. 4-chlorophenol was not consumed as a sole substrate by Pseudomonas putida but was consumed as a cometabolite with either glucose or phenol acting as the primary growth cosubstrate. Surprisingly, glucose was found to be the superior growth cosubstrate, suggesting that inexpensive sugars can be used to enhance the biodegradation of chlorophenol-contaminated sites. Glucose and the excreted metabolic products of the biodegradation process, including a bright yellow pigment, demonstrated negligible toxicity towards Artemia salina, unlike the phenol and 4-chlorophenol substrates. (orig.)

  16. Anaerobic co-digestion of spent coffee grounds with different waste feedstocks for biogas production.

    Science.gov (United States)

    Kim, Jaai; Kim, Hakchan; Baek, Gahyun; Lee, Changsoo

    2016-10-14

    Proper management of spent coffee grounds has become a challenging problem as the production of this waste residue has increased rapidly worldwide. This study investigated the feasibility of the anaerobic co-digestion of spent coffee ground with various organic wastes, i.e., food waste, Ulva, waste activated sludge, and whey, for biomethanation. The effect of co-digestion was evaluated for each tested co-substrate in batch biochemical methane potential tests by varying the substrate mixing ratio. Co-digestion with waste activated sludge had an apparent negative effect on both the yield and production rate of methane. Meanwhile, the other co-substrates enhanced the reaction rate while maintaining methane production at a comparable or higher level to that of the mono-digestion of spent coffee ground. The reaction rate increased with the proportion of co-substrates without a significant loss in methanation potential. These results suggest the potential to reduce the reaction time and thus the reactor capacity without compromising methane production.

  17. Sewage sludge disintegration - a review of current processes; Klaerschlammdesintegration - Ueberblick ueber verschiedene Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, K. [ULTRAWAVES Wasser- und Umwelttechnologien GmbH, Hamburg (Germany); Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

    2003-07-01

    Anaerobic stabilisation is an established technology for reducing sewage sludge volumes, but it has the drawback of low conversion rates. The speed of the process is determined by the hydrolysis of the solid fraction of the sludge. According to the current state of knowledge, exoenzymes produced by the fermenting microorganisms attack the particulate material and dissolve monomers. Production of exoenzymes is an energy-consuming process for the microorganisms; it reduces the energy gain and slows down cell growth. The same bacteria are responsible for aerobic and anaerobic hydrolysis. Therefore, the process of sludge destabilisation can be intensified considerably by making the whole organic fraction biologically available, i.e. by replacing the slow stage of enzymatic sludge hydrolysis by a chemical, thermal or mechanical stage. Sludge disintegration by one of these processes would intensify anaerobic degradation, reduce sludge volumes and enhance biogas production. (orig.) [German] Die anaerobe Stabilisierung ist anerkannte Regel der Technik und fuehrt zu einem teilweisen Abbau der organischen Bestandteile des Rohschlammes. Eine Verminderung der zu entsorgenden Schlammmasse geht damit einher. Wesentlicher Nachteil der anaeroben Klaerschlammstabilisierung ist die geringe Umsatzleistung dieses Prozesses. Dem Aufschluss der Feststoffe/grossen Molekuele des Schlammes kommt eine Schluesselrolle zu: die Hydrolyse der Rohschlammfeststoffe stellt den geschwindigkeitsbestimmenden Teilschritt des aneroben Abbauprozesses dar. Nach den gegenwaertigen Vorstellungen greifen von den fermentierenden Mikroorganismen produzierte Exoenzyme das partikulaere Material an und loesen Monomere heraus. Die Herstellung der Exoenzyme ist fuer die Mikroorganismen energetisch sehr aufwendig und vermindert den Energiegewinn und damit das Zellwachstum. Die Hydrolyse ist unabhaengig davon, ob sie aerob oder anaerob erfolgt, sie wird von denselben Bakterien bewerkstelligt. Man kann sich demnach

  18. Unlocking the Energy Potential of Manure—An Assessment of the Biogas Production Potential at the Farm Level in Germany

    Directory of Open Access Journals (Sweden)

    Mattes Scheftelowitz

    2016-04-01

    Full Text Available Residues from animal husbandry are one of the major greenhouse gas (GHG emission sources in agriculture. The production of biogas from agricultural residues can reduce GHG emissions through an improved handling of the material streams such as manure storage. Additionally, biogas can substitute fossil energy carriers in the provision of heat, power, and transport fuels. The aim of this work is to estimate the manure potential for biogas production in Germany under the consideration of the farm size of livestock production. In Germany, cattle and pig farming is of major relevance with more than 130,000 farms throughout the country. To unlock the biogas potential of manure, the low energy density of manure, depending on the dry matter content, needs to be considered, meaning that biogas installations need to be built close to the manure production on the farm site. This not only results in a high number of biogas plants, but also due to the wide range of farm sizes in Germany, a huge number of very small biogas plants. Small biogas installations have higher specific investment costs. Together with the relatively low methane yields from manure, costs for power generation would be very high. Co-substrates with higher methane yield can lower the costs for biogas. Thus, the use of a co-substrate could help to use small manure potentials. Biogas plants with the necessary minimum size of 50 kWel installed power could be established at farms representing 12% of all cattle and 16.5% of all pigs respectively in Germany. Using excrement from pigs, farms representing 16.5% of the total amount of pigs could establish a biogas plant. The use of manure in combination with energy crops can increase the size of biogas plants on a farm site significantly. At cattle farms, the share would increase to 31.1% with 40% co-substrate and to 40.8% with 60% co-substrate. At pig farms, the share would increase to 36% if co-substrates were used.

  19. Predictive parameters of infectiologic complications in patients after TIPSS; Praediktive Parameter infektiologischer Komplikationen bei Patienten nach TIPSS-Anlage

    Energy Technology Data Exchange (ETDEWEB)

    Cohnen, M.; Saleh, A.; Moedder, U. [Institut fuer Diagnostische Radiologie, Universitaetsklinikum Duesseldorf (Germany); Luethen, R.; Bode, J.; Haeussinger, D. [Klinik fuer Gastroenterologie, Hepatologie und Infektiologie, Universitaetsklinikum Duesseldorf (Germany); Daeubener, W. [Institut fuer Mikrobiologie und Virologie, Universitaetsklinikum Duesseldorf (Germany)

    2003-02-01

    Aim To define predictive parameters of a complicated clinical course after the TIPSS procedure. Blood cultures were drawn prospectively in 41 patients from a central line and from the portal venous blood before stent placement as well as from the central line 20 min after intervention. C-reactive proteine (CRP) (mg/dl) and white blood cell count (WBC,/{mu}l) on the day of TIPSS-procedure (d0), the first (d1) and seven (d7) days after TIPSS were compared in patients with a complicated clinical course (spontaneous bacterial peritonitis, pneumonia, sepsis; group I) to patients without clinical complications (group II) Group I showed a significant increase in CRP (d0: 1.8{+-}1.0; d1: 3.2{+-}1.5; d7: 4.3{+-}3.2), and white blood cell count (d0: 7700{+-}2600; d1: 10800{+-}2800; d7: 7500{+-}1800) on the first day after TIPSS-procedure in comparison to group II (CRP: d0: 1.6{+-}0.6; d1: 1.8{+-}1.0; d7: 1.9{+-}0.6. WBC: d0: 6900{+-}1500; d1: 8000{+-}1600; d7: 7600{+-}1400).Microbiological analysis showed in 12% skin or oral flora in the last sample. The course of CRP and WBC-count during the first week after TIPSS procedure may indicate patients with a potential risk of a complicated clinical course. (orig.) [German] Fragestellung Definition praediktiver Parameter infektiologischer Komplikationen bei Patienten nach TIPSS-Anlage.Methodik Bei 41 Patienten wurden Blutproben prospektiv vor intrahepatischer Stentanlage zentralvenoes und portalvenoes sowie 20 min postinterventionell erneut zentralvenoes entnommen und mikrobiologisch analysiert. C-reaktives Protein (CRP) (mg/dl) und Leukozytenzahl (/{mu}l) wurden am Interventionstag (d0), am 1. (d1) sowie 7 Tage (d7) postinterventionell bestimmt. Patienten mit kompliziertem Verlauf (spontane bakterielle Peritonitis,Pneumonie, Sepsis; Gruppe 1) wurden von Patienten ohne klinische Komplikationen (Gruppe 2) unterschieden.Ergebnisse Gruppe 1 wies einen signifikanten Anstieg des CRP (d0: 1,8{+-}1,0; d1: 3,2{+-}1,5; d7: 4,3{+-}3,2) und

  20. The influence of the Desulfovibrio desulfuricans 14 ATCC 27774 on the corrosion of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Feio, M.J. [Portsmouth Univ. (United Kingdom). Microbiology Research Lab.; Rainha, V.; Fonseca, I.T.E. [Lisbon Univ. (Portugal). Dept. de Quimica e Bioquimica; Reis, M.A. [Universidade Nova de Lisboa, Lisbon (Portugal). Faculdade de Ciencias e Tecnologia; Lino, A.R. [Instituto de Tecologia Quimica e Biologica, Qeiras (Portugal)

    2000-10-01

    The involvement of sulphate-reducing bacteria (SRB) in microbially influenced corrosion (MIC) of steel and the serious implications associated with their presence in industrial environments have long been known and extensively described. Desulfovibrio desulfuricans ATCC 27774 is an interesting metabolic case of SRB, as it can use both sulphate and nitrate as respiratory substrates during lactate oxidation. This strain has been extensively studied from both a biochemical and structural point of view but, so far, restricted information is available concerning its role in MIC. This work describes a comparative study of the corrosive aggressivity of ATCC 27774 strain towards mild steel when grown either in lactate/sulphate or lactate/nitrate media. The carbon source and electron acceptor's consumption rates were analysed and the metabolic features were correlated with weight loss measurements and SEM observations. (orig.) [German] Die Beteiligung von sulfatreduzierenden Bakterien (SRB) bei der mikrobiologisch beeinflussten Korrosion (MIC) von Stahl und die Auswirkungen, die mit ihrer Anwesenheit in industriellen Umgebungen verbunden sind, sind seit langem bekannt und ausfuehrlich beschrieben. Desulfovibrio desulfuricans ATCC 27774 ist ein interessanter metabolischer Fall von SRB, da es sowohl Sulfat als auch Nitrat als Respirationssubstrat waehrend der Laktatoxidation nutzen kann. Diese Art ist sowohl vom biochemischen als auch vom strukturellen Standpunkt aus intensiv untersucht worden; bisher gibt es allerdings nur begrenzte Informationen ueber eine Rolle bei MIC. Diese Arbeit beschreibt eine Vergleichsstudie der Korrosivitaet der ATCC 27774 Art (bei Wachstum entweder in Laktat/Sulfat- oder Laktat/Nitrat-Medien) gegenueber unlegiertem Stahl. Die Kohlenstoffquelle und die Elektronenakzeptorverbrauchsrate wurden analysiert und die metabolischen Merkmale wurden mit Massenverlustmessungen und REM-Beobachtungen korreliert. (orig.)

  1. Solar reactors for freshwater treatment in developing countries with high radiation intensity, with particular regard to part-project No. 1: Microbiology, process conception. Final report; Solarreaktoren fuer die Trinkwasseraufbereitung in Entwicklungslaendern mit hoher Sonnenstrahlungsintensitaet unter besonderer Beruecksichtigung von Teilprojekt 1: Mikrobiologie, Verfahrenskonzeption. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Watzke, E.; Roth, M.; Hoffmeier, C.

    2000-07-01

    Simple and low-cost systems for freshwater disinfestation for developing countries with high solar radiation intensity were investigated for the purpose of providing freshwater of better microbiological quality to a wider population in order to prevent infectious diseases, especially diarrhoea diseases. The bactericidic effects of short-wave and long-wave solar radiation of the UV and NIR range in combination with heat were investigated. Special glasses with high UV-permeability were developed and tested for their applicability as tube materials in freshwater disinfestation systems. the systems were designed and constructed with a view to utilising the synergistic effects of UV and thermal radiation. For higher efficacy, the water is kept in an insulated tank at elevated temperature for several hours. Further, special-purpose glass vessels with high UV permeability were developed for disinfestation. In a follow-up project, long-term tests will be carried out in practical conditions in developing countries. [German] Das Ziel der Verbundforschung bestand in der Entwicklung einfacher, kostenguenstiger Anlagen und Vorrichtungen zur Trinkwasserentkeimung in Entwicklungslaendern mit hoher Sonnenstrahlungsintensitaet. Es soll damit ein Beitrag zur Bereitstellung von Trinkwasser mit wesentlich verbesserter mikrobiologischer Qualitaet fuer breite Bevoelkerungsschichten geleistet werden, um Infektionskrankheiten, insbesondere Diarrhoeerkrankungen zurueckzudraengen. Die bakterizide Wirkung der kurz- und langwelligen Sonnenstrahlung im UV- bzw. NIR-Bereich in Kombination mit Waermeeinwirkungen wurde untersucht. Spezielle hoch UV-durchlaessige Glaeser wurden entwickelt und ihre Eignung fuer einen Einsatz in Trinkwasserentkeimungsanlagen (TWEA) getestet. Mit hoch UV-druchlaessigen Rohren aus Spezialglaesern ausgeruestete TWEA wurden konstruiert und gebaut, mit denen der synergistische Effekt von UV- und Waermestrahlung der Sonne zur Trinkwasserdesinfektion genutzt wird. Zur

  2. Pathogenesis of rheumatoid arthritis and cartilage degradation - investigations by in vitro {sup 1}H NMR spetroscopy; Pathogenese der Rheumatoiden Arthritis und Knorpelabbau - Untersuchungen mit in vitro {sup 1}H-NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, J.; Arnhold, J.; Arnold, K. [Leipzig Univ. (Germany). Inst. fuer Medizinische Physik und Biophysik

    2000-07-01

    Degenerative joint diseases like rheumatoid arthritis are accompanied by a progradient degradation of the articular cartilage matrix. Although the details of cartilage destruction are not yet completely understood, it is assumed that secreted products of stimulated neutrophilic granulocytes are massively involved in such processes. This paper discusses the in vitro application of high-resolution proton NMR spectroscopy (600 MHz) for the study of pathologically changed human synovial fluids and the detection of metabolites and degradation products in fluids obtained by punctation. Additionally, it is explained what resonances may serve as indicators for the different pathological processes of cartilage degradation (effects of reactive oxygen species and enzymes). (orig.) [German] Degenerative Gelenkserkrankungen wie die Rheumatoide Arthritis sind mit dem Abbau der Knorpelmatrix verbunden. Obwohl die Mechanismen der Knorpeldestruktion noch bei weitem nicht verstanden sind, gehen wir davon aus, dass die sekretierten Produkte stimulierter neutrophiler Granulozyten wesentlich an diesen Prozessen beteiligt sind. Der vorliegende Aufsatz diskutiert den in vitro Einsatz der hochaufloesenden {sup 1}H-NMR-Spektroskopie (600 MHz) zur Untersuchung pathologisch veraenderter Synovialfluessigkeiten und den Nachweis von Metaboliten bzw. Abbauprodukten des Gelenkknorpels in Gelenkpunktaten. Es wird ausserdem dargelegt, inwieweit die einzelnen NMR-Signale Rueckschluesse auf die unterschiedlichen Schaedigungsmechanismen (Wirkung von reaktiven Sauerstoffverbindungen bzw. Enzymen) zulassen. (orig.)

  3. Watermanagement - related and ecological demands on brown-coal mining. A statement of position; Wasserwirtschaftlich-oekologische Forderungen fuer den Braunkohlenabbau. Positionspapier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    This statement of position aims to identify influences exerted before, during and after brown-coal open-pit mining activities and to assess them in general terms from a water-management and ecological viewpoint. The form chosen is that of individual, concise postulates. Each of these is followed by an explanation. To illustrate the great variety of potentially arising problems, the major German brown-coal mining districts Lausitz, eastern Germany, and Lower Rhine are dealt with. A particular characteristic of the eastern German and Lausitz mining districts is that as the demand structure abruptly collapsed early in the 90s, closures became necessary on a large scale without preparatory measures having been taken. (orig.) [Deutsch] Mit dem vorliegenden Positionspapier wurde der Versuch unternommen, die Beeinflussungen vor, waehrend und nach dem Abbau von Braunkohle im Tagebaubetrieb inhaltlich zu erfassen und aus wasserwirtschaftlich-oekologischer Sicht verallgemeinernd zu bewerten. Dabei ist die From einzelner kurzgefasster Forderungen gewaehlt worden. Jede dieser Forderungen ist durch eine Erlaeuterung untersetzt. Um die Vielfalt der auftretenden Probleme zu verdeutlichen, werden beispielhaft in einem Anhang die grossen deutschen Braunkohlenreviere in der Lausitz, in Mitteldeutschland und am Niederrhein vorgestellt. Fuer das Mitteldeutsche und das Lausitzer Revier ist besonders anzumerken, dass mit dem schlagartigen Zusammenbruch der Bedarfsstruktur am Anfang der 90er Jahre in grossem Umfang Stillegungen ohne entsprechende Vorarbeiten notwendig wurden. (orig.)

  4. Three-dimensional calculation of pollutant migration via compressible two-phase flow, for analysis of the methods of in situ air sparging and soil vapor extraction; Raeumliche Berechnung des Schadstofftransportes mit einer kompressiblen Zweiphasenstroemung zur Untersuchung der Drucklufteinblasung und Bodenluftabsaugung

    Energy Technology Data Exchange (ETDEWEB)

    Kuepper, S.

    1997-12-01

    In this study an analysis method is presented which allows numerical simulation of in situ air sparging coupled with soil vapor extraction. The improved FE-program takes the following phenomena into account: - Two-phase flow of compressible air and incompressible water - convective-dispersive contamination migration with air and water - transfer of volatile components from liquid phase to gas and water phase - sorption of contaminants onto soil - transfer of contaminants between air and water phase - biological processes. By means of back calculations of the results of laboratory experiments made by Eisele (1989) it was shown that with the developed program GWLCOND some of the necessary parameters for the numerical simulation of remedial systems can be determined. (orig./SR) [Deutsch] In dieser Arbeit wird ein Verfahren vorgestellt, mit dem eine numerische Simulation der Drucklufteinblasung und Bodenluftabsaugung durchgefuehrt werden kann. Das weiterentwickelte FE-Programmsystem beinhaltet folgende Ablaeufe: - Zweiphasenstroemung der kompressiblen Luft- und der inkompressiblen Wasserphase - Konvektiv-dispersiver Schadstofftransport mit der Gas- und der Wasserphase - Uebergang fluessiger Schadstoffe in die Gas- und in die Wasserphase - Sorption der Schadstoffe an der Feststoffphase - Uebergang der Schadstoffe zwischen der Gas- und der Wasserphase - Biologischer Abbau. Anhand der Nachrechnung eines Laborversuches von Eisele (1989) wird gezeigt, wie mit dem entwickelten Transportprogramm GWLCOND ein Teil der fuer die numerische Simulation des Sanierungsverfahrens benoetigten Kennwerte ermittelt werden kann. (orig./SR)

  5. Internet, Kapitalismus und periphere Entwicklung im Waldviertel

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2015-03-01

    Full Text Available Das Waldviertel ist eine strukturschwache Region im Norden Österreichs, die eine innere Peripherie und innere Kolonie des österreichischen und europäischen Kapitalismus darstellt. Dieser Artikel analysiert die politische Ökonomie des Internets im Waldviertel. Das Waldviertel ist konfrontiert mit hohen Ausbeutungsraten im Rahmen einer imperialistischen Arbeitsteilung, Werttransfer, ungleichem Tausch, Niedriglöhnen, der Abwanderung der Textilindustrie, hoher Arbeitslosigkeit, Landflucht, dem Abbau öffentlicher Infrastruktur und Bevölkerungsrückgang. Die Analyse verdeutlicht, dass die Situation des Waldviertels als innere Peripherie der kapitalistischen Zentren die Kommunikationsverhältnisse prägt. Der Zugang zu Computern, dem Internet und Breitband ist im Waldviertel schlechter als in anderen Regionen, die Internet- und Mobiltelefonverbindungsgeschwindigkeit ist tendenziell langsamer und die Region ist eher unattraktiv für WissensarbeiterInnen. Es gibt im Waldviertel auch Ansätze einer Alternativökonomie, die den Imperialismus infrage stellen. Im Bereich der Informationsökonomie bestehen Potenziale für die Gründung von sozialistischen Kooperativen im Bereich Hardware, Software und soziale Medien, die die kapitalistische Informationsgesellschaft infrage stellen und für Alternativen kämpfen.

  6. Erektile Dysfunktion, Phosphodiesterase-5-Hemmer und KHK - die Sicht des Kardiologen

    Directory of Open Access Journals (Sweden)

    Schmid P

    2004-01-01

    Full Text Available Die erektile Dysfunktion (ED kommt vermehrt bei Patienten mit koronarer Herzkrankheit (KHK vor und wird üblicherweise mit Phosphodiesterase- 5-Hemmern (PDE-5-Hemmer wie Sildenafil, Vardenafil und Tadalafil behandelt. Dies geht mit einem systemischen Blutdruckabfall von bis zu 10 mmHg systolisch und bis 6 mmHg diastolisch einher. Die Herzfrequenz bleibt gleich oder steigt minimal an, das Doppelprodukt (RR sys x HF als Maß des myokardialen Sauerstoffverbrauches bleibt unverändert oder sinkt ab. Koronarangiographische Untersuchungen bei KHK-Patienten unter Sildenafil ergaben gegenüber Placebo keine Unterschiede in der Hämodynamik. Auch die Koronarreserve, die Blutflußgeschwindigkeit, der Durchmesser der Koronararterien, das Blutflußvolumen und der Koronargefäßwiderstand blieben unbeeinflußt. Die körperliche Leistungsfähigkeit wurde durch Sildenafil und Vardenafil nicht verändert. Eine kardiovaskuläre Exzeßmortalität liegt durch Einnahme von PDE-5-Hemmern nicht vor. Absolute Kontraindikation für eine Therapie mit PDE-5-Hemmern ist die gleichzeitige Gabe von NO-Donatoren (Nitrate, Molsidomin, Nitroprussid-Natrium, relative Kontraindikationen sind eine akute Koronarinsuffizienz, Herzinsuffizienz mit niedrigem Blutdruck, vorbestehende antihypertensive 3- bis 4-fach-Kombinationstherapie, Pharmaka, die den Abbau bzw. die Elimination von PDE-5-Hemmern reduzieren, sowie Antiarrhythmika der Klasse III.

  7. Simulation method for determining biodegradation in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Schoeberl, P.; Guhl, W. [Henkel KGaA, Duesseldorf (Germany). Hauptabteilung Oekologie; Scholz, N. [OXENO GmbH, Marl (Germany); Taeger, K. [BASF AG, Ludwigshafen am Rhein (Germany)

    1998-07-01

    OECD guidelines and EU directives on the biological testing of chemicals contain no methods able to simulate biodegradation in surface waters. The surface water simulation method presented in this paper is suitable for closing this gap. The species in the autochthonous biocoenosis used in the method form part of the food web in natural surface waters. The microbial degradation activity measured by the half-life is comparable with that in surface waters. The degrees of degradation measured in this surface water simulation method can be applied to natural surface waters. (orig.) [Deutsch] Die OECD- und EU-Richtlinien zur biologischen Pruefung von Chemikalien enthalten kein Verfahren, mit dem der biologische Abbau in Fliessgewaessern simuliert werden kann. Das in dieser Arbeit vorgestellte Fliessgewaesser-Simulationsmodell ist geeignet, diese Luecke zu schliessen. Die Arten der autochthonen Biocoenose des Modells sind Glieder im Nahrungsnetz natuerlicher Fliessgewaesser. Die an der Halbwertszeit gemessene mikrobielle Abbauaktivitaet ist mit derjenigen in Fliessgewaessern vergleichbar. Die im Fliessgewaesser-Simulationsmodell gemessenen Abbaugrade sind auf natuerliche Fliessgewaesser uebertragbar. (orig.)

  8. Lexicalização e deslexicalização. Observações sobre a erosão da língua exemplificadas no alemão e no português do Brasil

    Directory of Open Access Journals (Sweden)

    Hardarik Blühdorn

    1999-11-01

    Full Text Available Der vorliegende Aufsatz behandelt am Beispiel des Deutschen und des brasilianischen Portugiesisch den Prozeß der Grammatikalisierung als ein umfassendes Modell für erosive Vorgänge in der Geschichte natürlicher Sprachen. Grammatikalisierung wird vorgestellt als Abbau der pragmatischen Vielseitigkeit, semantischen Konkretheit, syntaktischen Freiheit und phonetischen Substanz von Sprachelementen. Ihr Gesamtgebiet wird zerlegt in den Prozeß der Lexikalisierung, der polylexematische Elemente in monolexematische überführt, und den der Delexikalisierung, der lexematische Elemente zu sublexmatischen reduziert. Im Mittelpunkt dieser Vorgänge seht das Lexikon, das als der zentrale Elementvorrat der Sprache gesehen wird. Auch innerhalb des Lexikons setzt sich der Prozeß der Grammatikalisierung fort, von den lexikalischen Wortklassen über die Übergangsklassen zu den grammatischen Klassen. Die untere Grenze des Lexikons stellt eine kritische Schwelle dar, bis zu der dem Prozeß der Grammatikalisierung das sprachliche Recycling gegenübersteht, durch das lexematische Elemente über die Bildung neuer polylexematischer Einheiten in den Kreislauf zurückfließen. Unterhalb dieser Schwelle jedoch ist kein Recycling mehr möglich, so daß Elemente, die einmal den lexematischen Charakter verloren haben, auf die Dauer zum Verschwinden verurteilt sind. Die verschiedenen Etappen der Grammatikalisierung werden anhand konkreter Beispiele, zunächst aus dem brasilianichen Portugiesisch, anschließend aus dem Deutschen, vorgestellt und illustriert.

  9. Experimental investigation of rock salt by uniaxial pressure test after hydrostatic preloading; Experimentelle Untersuchung des Steinsalzes mittels einaxialem Drucktest mit hydrostatischer Vorbelastung

    Energy Technology Data Exchange (ETDEWEB)

    Filimonov, Yu.L.; Shafarenko, Y.M. [Podsemgasprom GmbH, Moskau (Russian Federation). Festigkeitslab.; Lavrov, A.V.; Shkuratnik, V.L. [Moskauer Staatsbergbauuniv., Moskau (Russian Federation). Lehrstuhl fuer Physikalisch-technische Kontrolle von Bergbauprozessen

    2000-06-01

    In situ stress measurements are an important rock mechanical task in the working of rock salt deposits, in gas and mineral oil storage and in the dumping of waste in salt mines. Estimation of the stresses and the stability of the rock is necessary both for correct dimensioning of the underground cavities and also in their construction or operation. Predominantly the Hydro Frac and overdrilling methods are currently used for stress measurement. Objective restrictions, which are characteristic of these two methods, cause scientists to seek new stress measuring methods, some of which are based on other physical principles. One of the possibilities is to utilise the memory capacity of the rock and corresponding memory effects. (orig.) [German] Eine wichtige gebirgsmechanische Aufgabe beim Abbau von Steinsalzlagerstaetten, bei Gas- und Mineraloelspeicherung sowie beim Deponieren von Abfaellen im Salzgebirge stellen In-Situ-Spannungsmessungen dar. Die Einschaetzung der Spannungen und der Stabilitaet des Gebirges ist sowohl fuer richtige Dimensionierung der untertaegigen Hohlraeume als auch bei deren Bau beziehungsweise Betrieb notwendig. Zur Zeit werden fuer Spannungsmessung vorwiegend das Hydro-Frac- und das Ueberbohrverfahren verwendet. Objektive Einschraenkungen, die diesen beiden Methoden eigen sind, lassen Wissenschaftler staendig nach neuen Spannungsmessverfahren suchen, die zum Teil auf anderen physikalischen Prinzipien basieren. Eine der Moeglichkeiten besteht darin, die Gedaechtnis-Effekte auszunutzen. (orig.)

  10. Pollution and pollution tolerance as regards the sorption of organic chemicals in urban soils; Sorption organischer Chemikalien

    Energy Technology Data Exchange (ETDEWEB)

    Blume, H.P.; Wu Qinglan; Strehl, M. [Kiel Univ. (Germany). Inst. fuer Pflanzenernaehrung und Bodenkunde; Abend, S. [Kiel Univ. (Germany). Inst. fuer Anorganische Chemie; Rexilius, L. [Pflanzenschutzamt des Landes Schleswig-Holstein, Kiel (Germany); Schleuss, U. [Kiel Univ. (Germany). Oekologie-Zentrum]|[Zentrum fuer Agrarlandschafts- und Landnutzungsforschung Muencheberg (Germany)

    1997-12-31

    The behaviour of pollutants in soils concerning, for example, their immobilisation, transport, biodegradation, or uptake by useful plants is to large degree determined by the sorption properties of the soil in question. The degree of sorption is an all-important parameter in any model description of the behaviour of pollutants in soils. The aim of the present part-project was to estimate by means of simple field methods the binding capacity of anthropogenic urban soils for environmentally consequential organic chemicals and to assess the results with regard to soil and water protection. [Deutsch] Das Verhalten von Schadstoffen in Boeden, wie z.B. Immobilisierung, Transport, biologischer Abbau, Aufnahme durch Kulturpflanzen, wird von den Sorptionseigenschaften im Boden wesentlich beeinflusst. Bei allen Modellbeschreibungen ueber das Verhalten von Schadstoffen in Boeden ist die Staerke der Sorption ein unersetzbarer Parameter. Ziel dieses Teilprojektes war es, das Bindungsvermoegen der anthropogenen Stadtboeden fuer umweltrelevante organische Chemikalien mittels einfacher Feldmethoden abzuschaetzen und im Hinblick auf Boden- und Gewaesserschutz zu bewerten. (orig./SR)

  11. Photovoltaic energy conversion: Power from the sun. Technology, economic efficiency, market trends. 4. rev. and act. ed.; Photovoltaik - Strom aus der Sonne. Technologie, Wirtschaftlichkeit und Marktentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, J. (ed.)

    1999-07-01

    The book reviews the physical and technical fundamentals of photovoltaic energy conversion, outlines the state of the art and presents examples, and goes into future prospects. [German] Mit Photovoltaik-Systemen laesst sich aus Solarenergie besonders umweltfreundlich und wartungsarm Elektrizitaet erzeugen. Diese Technologie traegt zur Schonung der fossilen Energievorraete und zum Abbau von Risiken in der Energieversorgung bei. In vielen Faellen ist sie nicht nur die komfortablere, sondern auch die wirtschaftlichere Loesung. Sie bietet besonders in den Laendern der Dritten Welt sehr guenstige, noch zu wenig genutzte Moeglichkeiten der Energieversorgung. Schwerpunkte heutiger Forschung sind die Erhoehung des Wirkungsgrades, die Zuverlaessigkeit der Komponenten und die Reduzierung der Kosten. Wirtschaftlichkeit ist jedoch eines von mehreren Kriterien bei der Wahl der optimalen Energieversorgung. Andere Vorzuege der Photovoltaik wie Geraeusch- und Emissionsfreiheit, Zuverlaessigkeit und Wartungsarmut koennen in vielen Faellen von groesserer Bedeutung sein als reine Kostenueberlegungen. Dieser Band fuehrt in die physikalischen und technischen Grundlagen ein, beschreibt, auch anhand von zahlreichen Beispielen, den Stand der Anwendungstechnik und zeigt Zukunftsperspektiven auf. (orig.)

  12. Product analyses and kinetic studies on gas phase oxidation of the fuel additive ethyl tert-butyl ether and its products; Produktanalysen und Kinetikuntersuchungen der Gasphasenoxidation des Kraftstoffadditivs Ethyl-tert-butylether und seiner Produkte

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.H.; Thuener, L.

    1997-04-01

    The widespread use of the additive ETBE in gasoline leads to an increased release of this compound into the atmosphere via evaporation or exhaust fumes. In order to determine the influence of this additive on trace gas cycles it is first necessary to carry out studies on the degradation mechanisms and pertinent kinetic properties of this substance. The aim of the present study was to examine the degradation mechanisms of the fuel additive t-butyl ethyl ether under atmospheric conditions. The reactions of the main degradation products (t-butyl formiate and t-butyl acetate, together ca. 80%) were also studied in order to obtain as complete a picture of the degradation paths as possible. This was to permit an assessment of the influence of ETBE and its products on tropospheric trace gas cycles and ozone formation. [Deutsch] Bei haeufigem Zusatz von ETBE in Benzin wird diese Verbindung durch Verdampfung oder als Abgas verstaerkt in die Atmosphaere abgegeben. Um den Einfluss des Additivs auf die Spurengas-Kreislaeufe zu bestimmen, sind daher Untersuchungen noetig, um die Abbau-Mechanismen und die zugehoerigen kinetischen Daten zu ermitteln. Das Ziel dieser Arbeit ist die Untersuchung der Abbaumechanismen des Kraftstoffadditivs t-Butylethylether unter atmosphaerischen Bedingungen. Fuer eine moeglichst vollstaendige Analyse des Abbauweges werden auch die Reaktionen der Hauptabbauprodukte (t-Butylformiat und t-Butylacetat, zusammen etwa 80%) untersucht. Dadurch soll der Einfluss auf troposphaerische Spurengas-Kreislaeufe und auf die Ozonbildung von ETBE und seinen Produkten abgeschaetzt werden. (orig./SR)

  13. Microbial rehabilitation of soils in the vicinity of former coking plants; Mikrobielle Sanierung von Kokereiboeden

    Energy Technology Data Exchange (ETDEWEB)

    Knackmuss, H.J. [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik, Stuttgart (Germany); Bryniok, D. [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik, Stuttgart (Germany)

    1996-12-31

    Two airlift reactors with a nominal volume of 15 liters were provided with a closed aeration circuit. This mode of operation for the first time permitted to determine the carbon balance of PAH degradation. A mineralisation rate of approx. 35% was found by this method, whereas in experiments performed in shaking bottles mineralisation was always over 60% in the case of PAH mixtures. Use of PAH mixtures leads to competitive effects. These effects were studied by means of bacterial pure cultures. Further fundamental studies were performed to find suitable solvents for PAH degradation in a culture system with two liquid phases and examine liquid-liquid extraction of PAH from soil washing water. (orig./SR) [Deutsch] Zwei Airliftreaktoren mit einem Nennvolumen von 15 Litern wurden mit einem geschlossenen Belueftungskreislauf versehen. Diese Betriebsweise erlaubte erstmals die Bestimmung einer Kohlenstoffbilanz des PAK-Abbaus. Diese ergab eine Mineralisation von ca. 35%, waehrend die Mineralisationsrate bei Versuchen im Schuettelkolben selbst im Falle von PAK-Gemischen immer ueber 60% lag. Bei der Verwertung von PAK-Gemischen treten Kompetitionseffekte auf. Diese wurden mit bakteriellen Reinkulturen untersucht. Weitere grundlegende Arbeiten betrafen die Auswahl geeigneter Loesungsmittel fuer den PAK-Abbau in einem Kultursystem mit zwei Fluessigphasen und die Fluessig/Fluessig-Extraktion von PAK aus Bodenwaschwasser. (orig./SR)

  14. Anaerobic digestion of sugar beet pulp in Russia

    Directory of Open Access Journals (Sweden)

    Irina Miroshnichenko

    2016-11-01

    Full Text Available In der russischen Landwirtschaft entstehen jährlich ca. 250 Mio. t Trockenmasse an organischen Abfällen, die derzeit nicht sinnvoll verwertet werden. In manchen Regionen gehören auch Zuckerrübenschnitzel zu diesen Abfallstoffen. Durch eine Nutzung dieser Reststoffe zur Biogasproduktion könnten negative Umweltwirkungen reduziert und ein wichtiger Beitrag zum Erreichen der russischen Klimaschutzziele geleistet werden. Daher soll in diesem Projekt untersucht werden, ob eine Substitution von Maissilage durch Zuckerrübenschnitzel möglich ist. Dazu wurde ein einfacher Batch-Test aufgebaut und anschließend der Abbau der Inhaltsstoffe nach Weender, der Biogasertrag sowie die Abbaukinetik bestimmt. Der Gesamtabbau der Inhaltstoffe nach Weender betrug circa 40 % bei beiden Substraten. Jedoch wurde bei den Zuckerrübenschnitzeln ein 35,5 % geringerer Biogasertrag ermittelt, da es zu einem Abfall des pH-Wertes im Reaktor kam und damit zu einer Hemmung der Biogasbildung. Eine Substitution von Maissilage ist möglich, jedoch sollten Zuckerrübenschnitzel nur in Kofermentation mit anderen Substraten eingesetzt werden.

  15. Membrane filtration process and bioreactor for elimination of chlorinated hydrocarbons from industrial effluents; Membranfiltration und Bioreaktor zur Eliminierung chlorierter Kohlenwasserstoffe aus Industrieabwaessern

    Energy Technology Data Exchange (ETDEWEB)

    Schierenbeck, A.

    2003-07-01

    Selective separation and elimination of chlorinated hydrocarbons from industrial effluents directly at the production site was to be achieved by a combined process including membrane technology and biodegradation. This way, closed cycle processes can be designed which will be a major contribution to environmental protection integrated in production processes. First, chlorinated hydrocarbons are characterized in terms of occurrence and biodegradability. Two model substances are discussed (3-chlorobenzoic acid and 4-chlorophenol), and a practical example is presented. The fundamentals of the processes used for treatment of industrial effluents are outlined, and their advantages and shortcomings are discussed, with particular regard to integrated application in production processes. [German] Das Ziel dieser Arbeit ist die Entwicklung einer Verfahrenstechnik, bei der durch die Kombination der Membrantechnik mit dem biologischen Abbau die selektive Abtrennung und Eliminierung chlorierter Kohlenwasserstoffe aus dem Industrieabwasser schon am Ort des Entstehens realisiert werden. Durch den Einsatz dieser Technik wird die Schliessung von Wasserkreislaeufen moeglich. Dies stellt fuer alle Bereiche, in denen chlorierte Kohlenwasserstoffe in das Abwasser gelangen koennen, einen wichtigen Beitrag zum produktionsintegrierten Umweltschutz dar. Dazu wird zunaechst die Problemstoffgruppe der chlorierten Kohlenwasserstoffe hinsichtlich ihres Auftretens und der biologischen Abbaubarkeit charakterisiert. Zwei Modellsubstanzen (3-Chlorbenzoesaeure und 4-Chlorphenol) werden diskutiert sowie ein Beispiel aus der Praxis vorgestellt, bei dem ein Abwasser mit chlorierten Kohlenwasserstoffen anfaellt. Die Grundlagen der verwendeten Verfahren zur Behandlung von Industrieabwaessern mit entsprechenden Abwasserinhaltsstoffen werden dargestellt. Die Moeglichkeiten und Grenzen dieser Verfahren, insbesondere im Hinblick auf den produktionsintegrierten Einsatz, werden diskutiert. (orig.)

  16. Dispersion behaviour of rape oil methyl ester and rape-oil-based hydraulic oils in soils and on soil surfaces with due consideration to the technical performance capabilities of the hydraulic oils. Part-project 1: studies on model ecosystems. Part-project 2: provision of oils with defined degrees of ageing. Final report; Ausbreitungsverhalten von Rapsoelmethylester und Hydraulikoelen auf Rapsoelbasis im Boden und auf Bodenoberflaechen unter Beruecksichtigung der technischen Leistungsfaehigkeit der Hydraulikoele. Teilvorhaben 1: Untersuchungen an Modelloekosystemen. Teilvorhaben 2: Bereitstellung definiert gealterter Hydraulikoele. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Paul, W.; Schuett, C.; Roemer, A.; Foelster, N.; Lemke, M.

    2001-07-01

    The purpose of the present cooperative research project is to study the toxicity, the degradation and in particular the dispersion behaviour of biologically rapidly degradable hydraulic oils and rape oil methyl esters (RME) in soils and waters with a special focus on hydraulic oils. This is to serve as a basis for developing guidelines for action in the event of accidents involving biologically rapidly degradable hydraulic fluids that ensure proper accident reporting and handling. The outcome of the cooperative research project is to permit a first risk assessment for the soil and water compartments in the event of accidents involving hydraulic oils and RME. Another task is to clarify to what extent it is permissible to deviate from the usual measures prescribed for oil accidents involving crude oil when biologically rapidly degradable hydraulic oils or RME are involved instead. [German] Ziel des Verbundvorhabens ist es, die Toxizitaet, den Abbau und insbesondere das Ausbreitungsverhalten von biologisch schnell abbaubaren Hydraulikoelen und Rapsoelmethylester (RME) in Boden und Wasser zu untersuchen, wobei der Schwerpunkt der Arbeiten bei den Hydraulikoelen liegt. Damit sollen Verfahrensrichtlinien angegeben werden, die im Falle von Unfaellen mit biologisch schnell abbaubaren Hydraulikfluessigkeiten oder Biodiesel eine angemessene Unfallaufnahme und -abwicklung sicherstellen. Als Ergebnis des Verbundvorhabens soll eine erste Risikoabschaetzung fuer die Kompartimente Boden und Wasser bei Unfaellen mit Hydraulikoelen und RME moeglich sein. Darueber hinaus soll geklaert werden, inwieweit Abweichungen von den ueblichen Massnahmen bei Oelunfaellen mit Mineraloelprodukten im Vergleich zu biologisch schnell abbaubaren Hydraulikoelen oder RME moeglich sind. (orig.)

  17. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  18. Energetic conversion (biogas) of used edible oils by means of co-digestion together with various waste materials from the food industry; Valorisation energetique (biogaz) d'huiles comestibles usagees par codigestion avec differents dechets d'origine agroalimentaire

    Energy Technology Data Exchange (ETDEWEB)

    Membrez, Y.; Fruteau de Laclos, H.

    2002-07-01

    The aim of this project was the valorisation of used edible oils by co-digestion together with agricultural or food waste, without any risk for human and animal health. It included the technical economical aspects. In the bibliographic part a state-of-the-art on fat digestion in Switzerland and Europe was done. The possible co-substrates were examined, under a biological aspect as well as economical and strategic aspects. Food waste from restaurants and canteens, that are used up to now for pig feeding, were retained. The co-digestion gives a new perspective for the valorisation of this kind of waste, whose traditional way of valorisation is compromised by the new EU directives. The experimental part aimed to define the possibilities and limits for the co-digestion of used edible oil with food waste as co-substrate. The study was done in a 690 litres bio-reactor. The results showed that co-digestion of edible oil with food waste is feasible with interesting performances, if oil doesn't account for more than 15% of the mixture (on dry matter). Biogas production amounted to 400-450 litres per kg input COD (chemical oxygen demand), with 60-65% CH{sub 4}. Based on the observed results a tender document was done, in order to consult manufacturers of co-digestion plants. An economical simulation was realised on the basis of the most complete offer. This simulation revealed that a benefit of CHF 3500 per year can be obtained for a plant processing 200 t/y edible oil and 9000 t/y food waste. Co-digestion allows for valorisation of edible oil, together with a co-substrate whose traditional utilisation will not be possible in the future. It leads to the production of renewable energy, with a positive economical balance. (author)

  19. Modelling anaerobic co-digestion in Benchmark Simulation Model No. 2: Parameter estimation, substrate characterisation and plant-wide integration.

    Science.gov (United States)

    Arnell, Magnus; Astals, Sergi; Åmand, Linda; Batstone, Damien J; Jensen, Paul D; Jeppsson, Ulf

    2016-07-01

    Anaerobic co-digestion is an emerging practice at wastewater treatment plants (WWTPs) to improve the energy balance and integrate waste management. Modelling of co-digestion in a plant-wide WWTP model is a powerful tool to assess the impact of co-substrate selection and dose strategy on digester performance and plant-wide effects. A feasible procedure to characterise and fractionate co-substrates COD for the Benchmark Simulation Model No. 2 (BSM2) was developed. This procedure is also applicable for the Anaerobic Digestion Model No. 1 (ADM1). Long chain fatty acid inhibition was included in the ADM1 model to allow for realistic modelling of lipid rich co-substrates. Sensitivity analysis revealed that, apart from the biodegradable fraction of COD, protein and lipid fractions are the most important fractions for methane production and digester stability, with at least two major failure modes identified through principal component analysis (PCA). The model and procedure were tested on bio-methane potential (BMP) tests on three substrates, each rich on carbohydrates, proteins or lipids with good predictive capability in all three cases. This model was then applied to a plant-wide simulation study which confirmed the positive effects of co-digestion on methane production and total operational cost. Simulations also revealed the importance of limiting the protein load to the anaerobic digester to avoid ammonia inhibition in the digester and overloading of the nitrogen removal processes in the water train. In contrast, the digester can treat relatively high loads of lipid rich substrates without prolonged disturbances.

  20. Valorisation of used cooking oil sludge by codigestion with swine manure.

    Science.gov (United States)

    Fierro, J; Martínez, E J; Morán, A; Gómez, X

    2014-08-01

    The addition of lipid wastes to the digestion of swine manure was studied as a means of increasing biogas production. Lipid waste was obtained from a biodiesel plant where used cooking oil is the feedstock. Digestion of this co-substrate was proposed as a way of valorising residual streams from the process of biodiesel production and to integrate the digestion process into the biorefinery concept. Batch digestion tests were performed at different co-digesting proportions obtaining as a result an increase in biogas production with the increase in the amount of co-substrate added to the mixture. Semi-continuous digestion was studied at a 7% (w/w) mass fraction of total solids. Co-digestion was successful at a hydraulic retention time (HRT) of 50 d but a decrease to 30 d resulted in a decrease in specific gas production and accumulation of volatile and long chain fatty acids. The CH4 yield obtained was 326 ± 46 l/kg VSfeed at an HRT of 50 d, while this value was reduced to 274 ± 43 l/kg VSfeed when evaluated at an HRT of 30 d. However these values were higher than the one obtained under batch conditions (266 ± 40 l/kg VSfeed), thus indicating the need of acclimation to the co-substrate. Despite of operating at low organic loading rate (OLR), measurements from respirometry assays of digestate samples (at an HRT of 50 d) suggested that the effluent could not be directly applied to the soil as fertiliser and might have a negative effect over soil or crops. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Effect of trichloroethylene (TCE) and toluene concentrations on TCE and toluene biodegradation and the population density of TCE and toluene degraders in soil.

    OpenAIRE

    Mu, D Y; Scow, K M

    1994-01-01

    Toluene is one of several cosubstrates able to support the cometabolism of trichloroethylene (TCE) by soil microbial communities. Indigenous microbial populations in soil degraded TCE in the presence, but not the absence, of toluene after a 60- to 80-h lag period. Initial populations of toluene and TCE degraders ranged from 0.2 x 10(3) to 4 x 10(3) cells per g of soil and increased by more than 4 orders of magnitude after the addition of 20 micrograms of toluene and 1 microgram of TCE per ml ...

  2. Two-stage digestion of renewable raw materials. Applying the flooding process to utilizing grass silage; Zweiphasige Vergaerung nachwachsender Rohstoffe. Einsatz des Einstau-Verfahrens zur Verwertung von Grassilage

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H. [Hohenheim Univ. (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen; Jungbluth, T. [Stuttgart Univ. (Germany). Inst. fuer Agrartechnik

    2008-08-15

    The input of fibre-rich renewable raw materials, e.g. grass silage, as a co-substrate in agricultural biogas plants, often caused technical problems. Within the framework of this project a process is being developed, which makes it possible to digest grass silage as a single substrate, a process which additionally through a two-stage process better supplies what the bacteria involved require. An intermittently operating two- stage process is being used, which has had good results with degradation and methane yields. (orig.)

  3. Solutions for Foaming Problems in Biogas Reactors Using Natural Oils or Fatty Acids as Defoamers

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Angelidaki, Irini

    2015-01-01

    results from our previous extensive research along with some unpublished data on defoaming by rapeseed oil and oleic acid in manure-based biogas reactors. It was found that both compounds exhibited remarkable defoaming efficiency ranging from 30 to 57% in biogas reactors suffering from foaming problems...... promoted by the addition of protein, lipid, or carbohydrate co-substrates. However, in most cases, the defoaming efficiency of rapeseed oil was greater than that of oleic acid, and therefore, rapeseed oil is recommended to be used in biogas reactors to solve foaming problems....

  4. Storage of catch crops to produce biogas

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Ahring, Birgitte Kiær; Uellendahl, Hinrich

    2014-01-01

    Catch crop biomass is a promising co-substrate for manure-based biogas plants in Denmark since the cultivation of catch crops is mandatory to retain nutrients in the soil, contributing to protect the aquatic environment. In general, the growth period for catch crops is from harvest of the previous...... by chromatography. The specific methane yield of each silage sample was determined in triplicates and an average was calculated. The results indicated that OSR and GC could be successfully preserved as silage for up to 252 days and, therefore, be used as feedstock for biogas production throughout the year...

  5. Baker's yeast: production of D- and L-3-hydroxy esters

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    Baker's yeast grown under oxygen limited conditions and used in the reduction of 3-oxo esters results in a shift of the stereoselectivity of the yeast towards D-hydroxy esters as compared with ordinary baker's yeast. The highest degree of stereoselectivity was obtained with growing yeast or yeast...... harvested while growing. In contrast, the stereoselectivity was shifted towards L-hydroxy esters when the oxo esters were added slowly to ordinary baker's yeast supplied with gluconolactone as co-substrate. The reduction rate with gluconolactone was increased by active aeration. Ethyl L-(S)-3...

  6. Integrated airlift bioreactor system for on-site small wastewater treatment.

    Science.gov (United States)

    Chen, S L; Li, F; Qiao, Y; Yang, H G; Ding, F X

    2005-01-01

    An integrated airlift bioreactor system was developed, which mainly consists of a multi-stage loop reactor and a gas-liquid-solid separation baffle and possesses dual functions as bioreactor and settler. This integrated system was used for on-site treatment of industrial glycol wastewater in lab-scale. The strategy of gradually increasing practical wastewater concentration while maintaining the co-substrate glucose wastewater concentration helped to accelerate the microbial acclimation process. Investigation of microbial acclimation, operation parameters evaluation and microbial observation has demonstrated the economical and technical feasibility of this integrated airlift bioreactor system for on-site small industrial wastewater treatment.

  7. Deracemization of Secondary Alcohols by using a Single Alcohol Dehydrogenase

    KAUST Repository

    Karume, Ibrahim

    2016-03-01

    © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We developed a single-enzyme-mediated two-step approach for deracemization of secondary alcohols. A single mutant of Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase enables the nonstereoselective oxidation of racemic alcohols to ketones, followed by a stereoselective reduction process. Varying the amounts of acetone and 2-propanol cosubstrates controls the stereoselectivities of the consecutive oxidation and reduction reactions, respectively. We used one enzyme to accomplish the deracemization of secondary alcohols with up to >99% ee and >99.5% recovery in one pot and without the need to isolate the prochiral ketone intermediate.

  8. A highly efficient ADH-coupled NADH-recycling system for the asymmetric bioreduction of carbon-carbon double bonds using enoate reductases.

    Science.gov (United States)

    Tauber, Katharina; Hall, Melanie; Kroutil, Wolfgang; Fabian, Walter M F; Faber, Kurt; Glueck, Silvia M

    2011-06-01

    The asymmetric bioreduction of activated alkenes catalyzed by flavin-dependent enoate reductases from the OYE-family represents a powerful method for the production of optically active compounds. For its preparative-scale application, efficient and economic NADH-recycling is crucial. A novel enzyme-coupled NADH-recycling system is proposed based on the concurrent oxidation of a sacrificial sec-alcohol catalyzed by an alcohol dehydrogenase (ADH-A). Due to the highly favorable position of the equilibrium of ene-reduction versus alcohol-oxidation, the cosubstrate is only required in slight excess.

  9. Optimising the anaerobic co-digestion of urban organic waste using dynamic bioconversion mathematical modelling

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Boldrin, Alessio; Dorini, G.

    2016-01-01

    strategies for controlling and optimising the co-digestion process. The model parameters were maintained in the same way as the original dynamic bioconversion model, albeit with minor adjustments, to simulate the co-digestion of food and garden waste with mixed sludge from a wastewater treatment plant...... scenario analysis demonstrated that increasing the amount of mixed sludge in the co-substrate had a marginal effect on the reactor performance. In contrast, increasing the amount of food waste and garden waste resulted in improved performance....

  10. Anaerobic co-digestion of animal waste: swine manure and tuna fish waste

    Energy Technology Data Exchange (ETDEWEB)

    Otero, L.; Alvarez, J. A.; Lema, J. M.

    2009-07-01

    Anaerobic digestion has become an established and proven technology for the treatment of solid wastes. Co-digestion offers several possible ecological, technology and economical advantages. Anaerobic co-digestion can increase CH{sub 4} production of manure diesters in a 50-200% according to the operation conditions and the co-substrates used. Last September 2007, PROBIOGAS project started up with the objective of improving the production and use of biogas from co-digestion of farming, agricultural and industrial waste. Our research group takes part in the study of co-digestion of swine manure firstly with tuna fish waste and secondly with glycerine (bio diesel production waste). (Author)

  11. Microbial production of the flavonoids garbanzol, resokaempferol and fisetin

    DEFF Research Database (Denmark)

    2016-01-01

    The invention provides a genetically modified micro-organism comprising one or more transgene for the production of one or more of the flavonoids garbanzol, resokaempferol and fisetin. The micro-organism may be a bacterial or yeast cell engineered to express a metabolic pathway for garbanzol......, resokaempferol and/or fisetin biosynthesis. The invention further provides a method for producing garbanzol, resokaempferol and/or fisetin employing the genetically modified micro-organism of the invention. The genetically modified micro- organism may be used to convert a number of substrates and/or co......-substrates into fisetin via a fisetin biosynthetic pathway....

  12. Full-scale co-composting of hair wastes from the leather manufacturing industry and sewage sludge

    OpenAIRE

    Barrena Gómez, Raquel; Pagans i Miró, Estel·la; Vázquez Lima, Felícitas; Artola Casacuberta, Adriana; Sánchez Ferrer, Antoni

    2007-01-01

    A full-scale cocomposting experiment using hair wastes from the leather manufacturing industry and sewage sludge as cosubstrates was carried out with the aim of producing compost that may be used as an organic amendment in agriculture. A 1:1 weight ratio of hair wastes and sewage sludge was used based on experiments at smaller-scale. The resulting mixture was then amended with pruning wastes acting as bulking agent in a 1:1 volumetric ratio (mixture:pruning wastes). The experiment was carried...

  13. Metabolic network capacity of Escherichia coli for Krebs cycle-dependent proline hydroxylation.

    Science.gov (United States)

    Theodosiou, Eleni; Frick, Oliver; Bühler, Bruno; Schmid, Andreas

    2015-07-29

    Understanding the metabolism of the microbial host is essential for the development and optimization of whole-cell based biocatalytic processes, as it dictates production efficiency. This is especially true for redox biocatalysis where metabolically active cells are employed because of the cofactor/cosubstrate regenerative capacity endogenous in the host. Recombinant Escherichia coli was used for overproducing proline-4-hydroxylase (P4H), a dioxygenase catalyzing the hydroxylation of free L-proline into trans-4-hydroxy-L-proline with a-ketoglutarate (a-KG) as cosubstrate. In this whole-cell biocatalyst, central carbon metabolism provides the required cosubstrate a-KG, coupling P4H biocatalytic performance directly to carbon metabolism and metabolic activity. By applying both experimental and computational biology tools, such as metabolic engineering and (13)C-metabolic flux analysis ((13)C-MFA), we investigated and quantitatively described the physiological, metabolic, and bioenergetic response of the whole-cell biocatalyst to the targeted bioconversion and identified possible metabolic bottlenecks for further rational pathway engineering. A proline degradation-deficient E. coli strain was constructed by deleting the putA gene encoding proline dehydrogenase. Whole-cell biotransformations with this mutant strain led not only to quantitative proline hydroxylation but also to a doubling of the specific trans-4-L-hydroxyproline (hyp) formation rate, compared to the wild type. Analysis of carbon flux through central metabolism of the mutant strain revealed that the increased a-KG demand for P4H activity did not enhance the a-KG generating flux, indicating a tightly regulated TCA cycle operation under the conditions studied. In the wild type strain, P4H synthesis and catalysis caused a reduction in biomass yield. Interestingly, the ΔputA strain additionally compensated the associated ATP and NADH loss by reducing maintenance energy demands at comparably low glucose

  14. The biodegradation kinetics of polychlorinated biphenol in water/sediment systems; Cinetica de biodegradacion de bifenilos policlorados en sistemas agua/sedimento

    Energy Technology Data Exchange (ETDEWEB)

    Manzano Quinones, M. A.; Sales Marquez, D.; Quiroga Alonso, J. M.

    2001-07-01

    This article presents a kinetic study of the biodegradation process of a commercial mixture of polychlorinated biphenol. Aroclor 1242, in water/sediment systems using an acclimated mixed culture. The variables tested were: the sediment mass to water volume ratio (m/V), the addition of a co-substrate, the influence of biostimulation and bio increase and the addition of an ionic tensioactive. The results obtained employing the Middleton or General Bioremediation Model show that the model fits all the cases studied and makes it possible to obtain useful kinetic parameters such as the concentration of biodegradation-resistant substrate and the kinetic rate constant. (Author) 7 refs.

  15. Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin

    OpenAIRE

    Kazuhiro Nakamura; Hiroyuki Hasegawa

    2009-01-01

    Serotonin (5-hydroxytryptamine [5-HT]) has been implicated in a variety of physiological and pathological functions. Multiple steps of enzyme reactions enable biosynthesis of 5-HT. The first and rate-limiting step of the reaction is the synthesis of 5-hydroxy-L-tryptophan (5-HTP) from L-tryptophan. This step is dictated by an enzyme, tryptophan hydroxylase (TPH). TPH requires 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as a co-substrate of TPH. 5-HTP has been simply regarded as a precursor...

  16. Optimization of biogas production from Sargassum sp. using a design of experiments to assess the co-digestion with glycerol and waste frying oil.

    Science.gov (United States)

    Oliveira, J V; Alves, M M; Costa, J C

    2015-01-01

    A design of experiments was adopted to assess the optimal conditions for methane production from the macroalgae Sargassum sp. co-digested with glycerol (Gly) and waste frying oil (WFO). Three variables were tested: % total solids of algae (%TSSargassumsp.), co-substrate concentration (gGly/WFOL(-1)), and co-substrate type (Gly or WFO). The biochemical methane potential (BMP) of Sargassum sp. was 181±1L CH4kg(-1) COD. The co-digestion with Gly and WFO increased the BMP by 56% and 46%, respectively. The methane production rate (k), showed similar behaviour as the BMP, increasing 38% and 19% with Gly and WFO, respectively. The higher BMP (283±18L CH4kg(-1) COD) and k (65.9±2.1L CH4kg(-1) CODd(-1)) was obtained in the assay with 0.5% TS and 3.0gGlyL(-1). Co-digestion with glycerol or WFO is a promising process to enhance the BMP from the macroalgae Sargassum sp.

  17. TNT biotransformation potential of the clinical isolate of Salmonella typhimurium - potential ecological implications

    Directory of Open Access Journals (Sweden)

    Litake Geetanjali

    2005-01-01

    Full Text Available Out of fifty-six isolates screened three bacterial strains enriched with TNT either as sole source of nitrogen (for Salmonella typhimurium, Klebsiella pneumoniae or along with co-substrate (for Acinetobacter baumannii, have been carried out nitro group reduction under aerobic conditions. During studies, S. typhimurium found to have high potential (100% of 50 mg l-l in removal of TNT, than K. pneumoniae (70% of 20 mg l-l and A. baumannii (52% of 40 mg l-l, in presence of co-substrate. Therefore studies were focused on S. typhimurium, which had shown good growth, and protein contents, with disappearance of TNT, and concomitantly release of nitrite over the period of time. Removal of TNT was analyzed by HPLC, and nitrite liberation was consistently found coincided with TNT disappearance from the medium. As compared to earlier reports, 100% disappearance of TNT within 30 h by S. typhimurium is encouraging, and may indicate its potential in bioremediation of TNT. This is the first report on S. typhimurium, Klebsiella pneumoniae and Acinetobacter baumannii for transformation of TNT with nitrite release into the medium.

  18. Tyrosine aminotransferase from Leishmania infantum: A new drug target candidate

    Directory of Open Access Journals (Sweden)

    Miguel Angel Moreno

    2014-12-01

    Full Text Available Leishmania infantum is the etiological agent of zoonotic visceral leishmaniasis in the Mediterranean basin. The disease is fatal without treatment, which has been based on antimonial pentavalents for more than 60 years. Due to resistances, relapses and toxicity to current treatment, the development of new drugs is required. The structure of the L. infantum tyrosine aminotransferase (LiTAT has been recently solved showing important differences with the mammalian orthologue. The characterization of LiTAT is reported herein. This enzyme is cytoplasmic and is over-expressed in the more infective stages and nitric oxide resistant parasites. Unlike the mammalian TAT, LiTAT is able to use ketomethiobutyrate as co-substrate. The pharmacophore model of LiTAT with this specific co-substrate is described herein. This may allow the identification of new inhibitors present in the databases. All the data obtained support that LiTAT is a good target candidate for the development of new anti-leishmanial drugs.

  19. Differential scanning fluorometry signatures as indicators of enzyme inhibitor mode of action: case study of glutathione S-transferase.

    Directory of Open Access Journals (Sweden)

    Wendy A Lea

    Full Text Available Differential scanning fluorometry (DSF, also referred to as fluorescence thermal shift, is emerging as a convenient method to evaluate the stabilizing effect of small molecules on proteins of interest. However, its use in the mechanism of action studies has received far less attention. Herein, the ability of DSF to report on inhibitor mode of action was evaluated using glutathione S-transferase (GST as a model enzyme that utilizes two distinct substrates and is known to be subject to a range of inhibition modes. Detailed investigation of the propensity of small molecule inhibitors to protect GST from thermal denaturation revealed that compounds with different inhibition modes displayed distinct thermal shift signatures when tested in the presence or absence of the enzyme's native co-substrate glutathione (GSH. Glutathione-competitive inhibitors produced dose-dependent thermal shift trendlines that converged at high compound concentrations. Inhibitors acting via the formation of glutathione conjugates induced a very pronounced stabilizing effect toward the protein only when GSH was present. Lastly, compounds known to act as noncompetitive inhibitors exhibited parallel concentration-dependent trends. Similar effects were observed with human GST isozymes A1-1 and M1-1. The results illustrate the potential of DSF as a tool to differentiate diverse classes of inhibitors based on simple analysis of co-substrate dependency of protein stabilization.

  20. Characterization of the hydrophobic substrate-binding site of the bacterial beta class glutathione transferase from Proteus mirabilis.

    Science.gov (United States)

    Federici, Luca; Masulli, Michele; Di Ilio, Carmine; Allocati, Nerino

    2010-09-01

    Since their discovery, bacterial glutathione (GSH)transferases have been characterized in terms of their ability to catalyse a variety of different reactions on a large set of toxic molecules of xenobiotic or endobiotic origin. Furthermore the contribution of different residues in the GSH-binding site to GSH activation has been extensively investigated. Little is known, however, about the contribution to catalysis and overall stability of single residues shaping the hydrophobic co-substrate binding site (H-site). Here we tackle this problem by site-directed mutagenesis of residues facing the H-site in the bacterial beta class GSH transferase from Proteus mirabilis. We investigate the behaviour of these mutants under a variety of conditions and analyse their activity against several co-substrates, representative of the different reactions catalyzed by bacterial GSH transferases. Our work shows that mutations at the H-site can be used to modulate activity at the level of the different catalytic mechanisms operating on the chosen substrates, each mutation showing a different fingerprint. This work paves the way for future studies aimed at improving the catalytic properties of beta class GSH transferases against selected substrates for bioremediation purposes.

  1. Comparing environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy – A life cycle perspective

    DEFF Research Database (Denmark)

    De Vries, J.W.; Vinken, T.M.W.J; Hamelin, Lorie

    2012-01-01

    The aim of this work was to assess the environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy, from a life cycle perspective. This included assessing environmental impacts and land use change emissions (LUC) required to replace used co-substrates for an......The aim of this work was to assess the environmental consequences of anaerobic mono- and co-digestion of pig manure to produce bio-energy, from a life cycle perspective. This included assessing environmental impacts and land use change emissions (LUC) required to replace used co......-substrates for anaerobic digestion. Environmental impact categories considered were climate change, terrestrial acidification, marine and freshwater eutrophication, particulate matter formation, land use, and fossil fuel depletion. Six scenarios were evaluated: mono-digestion of manure, co-digestion with: maize silage......, maize silage and glycerin, beet tails, wheat yeast concentrate (WYC), and roadside grass. Mono-digestion reduced most impacts, but represented a limited source for bio-energy. Co-digestion with maize silage, beet tails, and WYC (competing with animal feed), and glycerin increased bio-energy production...

  2. Thermophilic co-digestion of cattle manure and food waste supplemented with crude glycerin in induced bed reactor (IBR).

    Science.gov (United States)

    Castrillón, L; Marañón, E; Fernández-Nava, Y; Ormaechea, P; Quiroga, G

    2013-05-01

    The aim of the present research work was to boost biogas production from cattle manure (CM) by adding food waste (FW) and crude glycerin (Gly) from the biodiesel industry as co-substrates. For this purpose, different quantities of FW and Gly were added to CM and co-digested in an induced bed reactor (IBR) at 55 °C. Sonication pre-treatment was implemented in the CM+Gly mixture, applying 550 kJ/kg TS to enhance the biodegradability of these co-substrates. The best results were obtained with mixtures of 87/10/3 (CM/FW/Gly) (w/w) operating at an organic loading rate of 7 g COD/L day, obtaining 92% COD removal, a specific methane yield of 640 L CH4/kg VS and a methane production rate of 2.6L CH4/L day. These results doubled those obtained in the co-digestion of CM and FW without the addition of Gly (330 L CH4/kg VS and 1.2L CH4/L day).

  3. Optimising the anaerobic co-digestion of urban organic waste using dynamic bioconversion mathematical modelling.

    Science.gov (United States)

    Fitamo, T; Boldrin, A; Dorini, G; Boe, K; Angelidaki, I; Scheutz, C

    2016-12-01

    Mathematical anaerobic bioconversion models are often used as a convenient way to simulate the conversion of organic materials to biogas. The aim of the study was to apply a mathematical model for simulating the anaerobic co-digestion of various types of urban organic waste, in order to develop strategies for controlling and optimising the co-digestion process. The model parameters were maintained in the same way as the original dynamic bioconversion model, albeit with minor adjustments, to simulate the co-digestion of food and garden waste with mixed sludge from a wastewater treatment plant in a continuously stirred tank reactor. The model's outputs were validated with experimental results obtained in thermophilic conditions, with mixed sludge as a single substrate and urban organic waste as a co-substrate at hydraulic retention times of 30, 20, 15 and 10 days. The predicted performance parameter (methane productivity and yield) and operational parameter (concentration of ammonia and volatile fatty acid) values were reasonable and displayed good correlation and accuracy. The model was later applied to identify optimal scenarios for an urban organic waste co-digestion process. The simulation scenario analysis demonstrated that increasing the amount of mixed sludge in the co-substrate had a marginal effect on the reactor performance. In contrast, increasing the amount of food waste and garden waste resulted in improved performance.

  4. Co-digestion of press water and food waste in a biowaste digester for improvement of biogas production.

    Science.gov (United States)

    Nayono, Satoto E; Gallert, Claudia; Winter, Josef

    2010-09-01

    Co-digestion of press water from organic municipal wastes and of homogenized food residues with defibered kitchen wastes (food waste) as the main substrate was examined to improve biogas production. Although the biowaste digester was operated already at high organic loading (OLR) of 12.3 kg CODm(-3)d(-1) during the week, addition of co-substrates not only increased biogas production rates but also improved total biogas production. By feeding the two co-substrates up to 20 kg CODm(-3)d(-1) gas production followed the increasing OLR linearly. When the OLR was further increased with food waste, not more gas than for 20 kg CODm(-3)d(-1) OLR was obtained, indicating the maximum metabolic capabilities of the microbes. During weekends (no biowaste available) food waste could substitute for biowaste to maintain biogas production. Addition of press water or food waste to biowaste co-digestion resulted in more buffer capacity, allowing very high loadings without pH control.

  5. A novel glucose oxidase biosensor based on poly([2,2';5',2″]-terthiophene-3'-carbaldehyde) modified electrode.

    Science.gov (United States)

    Guler, Muhammet; Turkoglu, Vedat; Kivrak, Arif

    2015-08-01

    In the study, the electrochemical behavior of glucose oxidase (GOx) immobilized on poly([2,2';5',2″]-terthiophene-3'-carbaldehyde) (poly(TTP)) modified glassy carbon electrode (GCE) was investigated. The biosensor (poly(TTP)/GOx/GCE) showed a pair of redox peaks in 0.1 M phosphate buffer (pH 7.4) solution in the absence of oxygen the co-substrate of GOx. In here, Poly(TTP)/GOx/GCE biosensor acts as the co-substrate instead of oxygen. Upon the addition of glucose, the reduction and oxidation peak currents increased until the active site of GOx was fully saturated with glucose. The apparent m was estimated 26.13 mM from Lineweaver-Burk graph. The biosensor displayed a good stability and bioactivity. The biosensor showed a high sensitivity (56.1 nA/mM), a linear range (from 0.5 to 20.15 mM), and a good reproducibility with 3.6% of relative standard deviation. In addition, the interference currents of glycin, ascorbic acid, histidine, uric acid, dopamine, arginine, and fructose on GOx biosensor were investigated. All that substances exhibited an interference current under 10%. It was not shown a marked difference between GOx biosensor and spectrophotometric measurement of glucose in serum examples. UV-visible spectroscopy and scanning electron microscopy (SEM) experiments of the biosensor were also performed.

  6. Anaerobic degradation of benzaldehyde in methanogenic granular sludge: the influence of additional substrates

    Energy Technology Data Exchange (ETDEWEB)

    Todini, O. (Environment Protection Dept., Eniricerche S.p.A., Rome (Italy)); Pol, L.H. (Wageningen Agricultural Univ. (Netherlands). Dept. of Environmental Technology)

    1992-12-01

    The degradation of benzaldehyde in methaogenic granular sludge was investigated in batch and in upflow anaerobic sludge blanked (UASB) reactors. The effect due to the presence of co-substrates, such as H[sub 2], sodium butyrate and sucrose, was studied using formaldehyde as a reference compound. The additional substrates enhanced the activity of benzaldehyde- and formaldehyde-degrading microorganisms (ACT[sub bdm] and ACT[sub fdm], respectively) and increased the transient production of benzyl alcohol and methanol. As a consequence, the concentrations of benzaldehyde and formaldehyde that caused 50% inhibition of the methanogenic activity (50% IC[sub m]) on sucrose were 3133 and 254 mg chemical oxygen demand (COD)/1 respectively, three times higher than the literature data values on acetate. Experiments performed in UASB reactors on benzaldehyde showed that the replacement of volatile fatty acids with sucrose as co-substrate improved the treatment capacity of the system from 0.73 to 4.36 kg COD benzaldehyde.m[sup -3].day[sup -1]. (orig.).

  7. Modern Biotechnological Polymer Synthesis: A Review

    Directory of Open Access Journals (Sweden)

    Miguel Dias

    2010-01-01

    Full Text Available The industrial implementation of cost- and eco-efficient production of bio-based polymeric materials such as polyhydroxyalkanoates (PHAs or polylactic acid (PLA requires the comprehension of all process steps. The article at hand provides an insight into recent advances in allocation, pretreatment and utilization of raw materials available for biopolymer production in different areas of the world. Further, the high potential and risks of applying continuous process conduction in comparison with batch and fed-batch fermentation mode are elucidated. It is shown that the process design for continuous PHA production strongly depends on the kinetic characteristics for growth and product formation of the applied production strain. In addition, the triggering of the biopolymer properties by fine-tuning of the polyester composition during biosynthesis is demonstrated. Here, the impact of certain process parameters like the partial oxygen tension on the intracellular metabolic fluxes and the supplementation of cosubstrates on the polyester composition are discussed. In addition, such specialists among microbes are presented that possess the metabolic prerequisites to accumulate high-quality copolyesters merely from cheap unrelated carbon sources without the necessity for supplying expensive cosubstrates. In the field of downstream processing, sustainable methods for product isolation during biopolymer production that do not have a negative influence on the environment are presented.

  8. Demand-driven energy supply from stored biowaste for biomethanisation.

    Science.gov (United States)

    Aichinger, Peter; Kuprian, Martin; Probst, Maraike; Insam, Heribert; Ebner, Christian

    2015-10-01

    Energy supply is a global hot topic. The social and political pressure forces a higher percentage of energy supplied by renewable resources. The production of renewable energy in form of biomethane can be increased by co-substrates such as municipal biowaste. However, a demand-driven energy production or its storage needs optimisation, the option to store the substrate with its inherent energy is investigated in this study. The calorific content of biowaste was found unchanged after 45 d of storage (19.9±0.19 kJ g(-1) total solids), and the methane yield obtained from stored biowaste was comparable to fresh biowaste or even higher (approx. 400 m(3) Mg(-1) volatile solids). Our results show that the storage supports the hydrolysis of the co-substrate via acidification and production of volatile fatty acids. The data indicate that storage of biowaste is an efficient way to produce bioenergy on demand. This could in strengthen the role of biomethane plants for electricity supply the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Biochemical and structural characterization of mouse mitochondrial aspartate aminotransferase, a newly identified kynurenine aminotransferase-IV

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Robinson, H.; Cai, T.; Tagle, D. A.; Li, J.

    2011-10-01

    Mammalian mAspAT (mitochondrial aspartate aminotransferase) is recently reported to have KAT (kynurenine aminotransferase) activity and plays a role in the biosynthesis of KYNA (kynurenic acid) in rat, mouse and human brains. This study concerns the biochemical and structural characterization of mouse mAspAT. In this study, mouse mAspAT cDNA was amplified from mouse brain first stand cDNA and its recombinant protein was expressed in an Escherichia coli expression system. Sixteen oxo acids were tested for the co-substrate specificity of mouse mAspAT and 14 of them were shown to be capable of serving as co-substrates for the enzyme. Structural analysis of mAspAT by macromolecular crystallography revealed that the cofactor-binding residues of mAspAT are similar to those of other KATs. The substrate-binding residues of mAspAT are slightly different from those of other KATs. Our results provide a biochemical and structural basis towards understanding the overall physiological role of mAspAT in vivo and insight into controlling the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  10. Biochemical and structural characterization of mouse mitochondrial aspartate aminotransferase, a newly identified kynurenine aminotransferase-IV.

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A; Li, Jianyong

    2011-10-01

    Mammalian mAspAT (mitochondrial aspartate aminotransferase) is recently reported to have KAT (kynurenine aminotransferase) activity and plays a role in the biosynthesis of KYNA (kynurenic acid) in rat, mouse and human brains. This study concerns the biochemical and structural characterization of mouse mAspAT. In this study, mouse mAspAT cDNA was amplified from mouse brain first stand cDNA and its recombinant protein was expressed in an Escherichia coli expression system. Sixteen oxo acids were tested for the co-substrate specificity of mouse mAspAT and 14 of them were shown to be capable of serving as co-substrates for the enzyme. Structural analysis of mAspAT by macromolecular crystallography revealed that the cofactor-binding residues of mAspAT are similar to those of other KATs. The substrate-binding residues of mAspAT are slightly different from those of other KATs. Our results provide a biochemical and structural basis towards understanding the overall physiological role of mAspAT in vivo and insight into controlling the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  11. Ferritin-Mediated Iron Sequestration Stabilizes Hypoxia-Inducible Factor-1α upon LPS Activation in the Presence of Ample Oxygen

    Directory of Open Access Journals (Sweden)

    Isabel Siegert

    2015-12-01

    Full Text Available Both hypoxic and inflammatory conditions activate transcription factors such as hypoxia-inducible factor (HIF-1α and nuclear factor (NF-κB, which play a crucial role in adaptive responses to these challenges. In dendritic cells (DC, lipopolysaccharide (LPS-induced HIF1α accumulation requires NF-κB signaling and promotes inflammatory DC function. The mechanisms that drive LPS-induced HIF1α accumulation under normoxia are unclear. Here, we demonstrate that LPS inhibits prolyl hydroxylase domain enzyme (PHD activity and thereby blocks HIF1α degradation. Of note, LPS-induced PHD inhibition was neither due to cosubstrate depletion (oxygen or α-ketoglutarate nor due to increased levels of reactive oxygen species, fumarate, and succinate. Instead, LPS inhibited PHD activity through NF-κB-mediated induction of the iron storage protein ferritin and subsequent decrease of intracellular available iron, a critical cofactor of PHD. Thus, hypoxia and LPS both induce HIF1α accumulation via PHD inhibition but deploy distinct molecular mechanisms (lack of cosubstrate oxygen versus deprivation of co-factor iron.

  12. Co-digestion to support low temperature anaerobic pretreatment of municipal sewage in a UASB-digester.

    Science.gov (United States)

    Zhang, Lei; Hendrickx, Tim L G; Kampman, Christel; Temmink, Hardy; Zeeman, Grietje

    2013-11-01

    The aim of this work was to demonstrate that co-digestion improves soluble sewage COD removal efficiency in treatment of low temperature municipal sewage by a UASB-digester system. A pilot scale UASB-digester system was applied to treat real municipal sewage, and glucose was chosen as a model co-substrate. Co-substrate was added in the sludge digester to produce additional methanogenic biomass, which was continuously recycled to inoculate the UASB reactor. Soluble sewage COD removal efficiency increased from 6 to 23%, which was similar to its biological methane potential (BMP). Specific methanogenic activity of the UASB and of the digester sludge at 15°C tripled to a value respectively of 43 and 39 mg CH4-COD/(g VSS d). Methane production in the UASB reactor increased by more than 90% due to its doubled methanogenic capacity. Therefore, co-digestion is a suitable approach to support a UASB-digester for pretreatment of low temperature municipal sewage.

  13. From Alkanes to Carboxylic Acids: Terminal Oxygenation by a Fungal Peroxygenase.

    Science.gov (United States)

    Olmedo, Andrés; Aranda, Carmen; Del Río, José C; Kiebist, Jan; Scheibner, Katrin; Martínez, Angel T; Gutiérrez, Ana

    2016-09-26

    A new heme-thiolate peroxidase catalyzes the hydroxylation of n-alkanes at the terminal position-a challenging reaction in organic chemistry-with H2 O2 as the only cosubstrate. Besides the primary product, 1-dodecanol, the conversion of dodecane yielded dodecanoic, 12-hydroxydodecanoic, and 1,12-dodecanedioic acids, as identified by GC-MS. Dodecanal could be detected only in trace amounts, and 1,12-dodecanediol was not observed, thus suggesting that dodecanoic acid is the branch point between mono- and diterminal hydroxylation. Simultaneously, oxygenation was observed at other hydrocarbon chain positions (preferentially C2 and C11). Similar results were observed in reactions of tetradecane. The pattern of products formed, together with data on the incorporation of (18) O from the cosubstrate H2 (18) O2 , demonstrate that the enzyme acts as a peroxygenase that is able to catalyze a cascade of mono- and diterminal oxidation reactions of long-chain n-alkanes to give carboxylic acids.

  14. Saponification of fatty slaughterhouse wastes for enhancing anaerobic biodegradability.

    Science.gov (United States)

    Battimelli, Audrey; Carrère, Hélène; Delgenès, Jean-Philippe

    2009-08-01

    The thermochemical pretreatment by saponification of two kinds of fatty slaughterhouse waste--aeroflotation fats and flesh fats from animal carcasses--was studied in order to improve the waste's anaerobic degradation. The effect of an easily biodegradable compound, ethanol, on raw waste biodegradation was also examined. The aims of the study were to enhance the methanisation of fatty waste and also to show a link between biodegradability and bio-availability. The anaerobic digestion of raw waste, saponified waste and waste with a co-substrate was carried out in batch mode under mesophilic and thermophilic conditions. The results showed little increase in the total volume of biogas, indicating a good biodegradability of the raw wastes. Mean biogas volume reached 1200 mL/g VS which represented more than 90% of the maximal theoretical biogas potential. Raw fatty wastes were slowly biodegraded whereas pretreated wastes showed improved initial reaction kinetics, indicating a better initial bio-availability, particularly for mesophilic runs. The effects observed for raw wastes with ethanol as co-substrate depended on the process temperature: in mesophilic conditions, an initial improvement was observed whereas in thermophilic conditions a significant decrease in biodegradability was observed.

  15. Harnessing dark fermentative hydrogen from pretreated mixture of food waste and sewage sludge under sequencing batch mode.

    Science.gov (United States)

    Nam, Joo-Youn; Kim, Dong-Hoon; Kim, Sang-Hyoun; Lee, Wontae; Shin, Hang-Sik; Kim, Hyun-Woo

    2016-04-01

    Food waste and sewage sludge are the most abundant and problematic organic wastes in any society. Mixture of these two wastes may provide appropriate substrate condition for dark fermentative biohydrogen production based on synergistic mutual benefits. This work evaluates continuous hydrogen production from the cosubstrate of food waste and sewage sludge to verify mechanisms of performance improvement in anaerobic sequencing batch reactors. Volatile solid concentration and mixing ratio of food waste and sludge were adjusted to 5 % and 80:20, respectively. Five different hydraulic retention times (HRT) of 36, 42, 48, 72, and 108 h were tested using anaerobic sequencing batch reactors to find out optimal operating condition. Results show that the best performance was achieved at HRT 72 h, where the hydrogen yield, the hydrogen production rate, and hydrogen content were 62.0 mL H2/g VS, 1.0 L H2/L/day, and ~50 %, respectively. Sufficient solid retention time (143 h) and proper loading rate (8.2 g COD/L/day as carbohydrate) at HRT 72h led to the enhanced performance with better hydrogen production showing appropriate n-butyrate/acetate (B/A) ratio of 2.6. Analytical result of terminal-restriction fragment length polymorphism revealed that specific peaks associated with Clostridium sp. and Bacillus sp. were strongly related to enhanced hydrogen production from the cosubstrate of food waste and sewage sludge.

  16. Mechanism of 2,4,6-trichlorophenol degradation by means of co substrates

    Directory of Open Access Journals (Sweden)

    NIU Yujing

    2012-12-01

    Full Text Available Domesticated glucose and 2,4,6-trichlorophenol (TCP degrading bacteria were respectively used for aerobic biodegradation of TCP by adding readily biodegradable organic matters (glucose,benzoic acid and phenol as co-substrates to investigate the mechanism of TCP degradation.Glucose degrading bacteria didn′t grow until 51 hours of adaptation period in absence of co-substrates,during which TCP could be degraded by the bacteria as sole carbon source.However,TCP was little degraded in presence of co-substrates.While TCP degrading bacteria were used for aerobic biodegradation of TCP,it only took about 43 hours of adaptation period for the bacteria to remove TCP in absence of co-substrates.Experimental results indicated that both glucose and TCP degrading bacteria could utilize TCP as sole carbon source to grow,and TCP was also effectively degraded simultaneously.So TCP removal rate was accelerated in presence of co-substrates due to secondary utilization instead of co-metabolism.

  17. Phototrophic Growth and Accumulation of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate by Purple Nonsulfur Bacterium Rhodopseudomonas palustris SP5212

    Directory of Open Access Journals (Sweden)

    M. Mukhopadhyay

    2013-01-01

    Full Text Available The ability of the phototrophic bacterium Rhodopseudomonas palustris SP5212 to produce polyhydroxyalkanoates (PHAs, poly(3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV] in particular was, assessed in acetate medium supplemented with hydroxybutyrate and valerate as cosubstrates. The isolate accumulated the polymer accounting for some 49.06% and 30% of cell dry weight when grown in hydroxybutyrate and valerate, respectively. PHA accumulation as well as 3HV monomer incorporation (30 mol% was maximum at 0.1% hydroxybutyrate, while valerate at 0.1% and 0.3% was suitable for total polymer accumulation and 3HV monomer incorporation, respectively. Cosupplementation of hydroxybutyrate and valerate in the ratio of 3 : 1 led to the accumulation of PHA accounting for 54% of cell dry weight, which contained more than 50 mol% of 3HV monomer. Moreover, the biphasic cultivation conditions with hydroxybutyrate as cosubstrate have improved the quality as well as quantity of the accumulated copolymer significantly.

  18. Anaerobic co-digestion of pig manure and crude glycerol at mesophilic conditions: biogas and digestate.

    Science.gov (United States)

    Astals, S; Nolla-Ardèvol, V; Mata-Alvarez, J

    2012-04-01

    Crude glycerol derived from biodiesel production is characterized by its high concentration of organic carbon and its solubility in water; properties that make it a suitable co-substrate to improve the efficiency of a manure digester. An increase of about 400% in biogas production was obtained under mesophilic conditions when pig manure was co-digested with 4% of glycerol, on a wet-basis, compared to mono-digestion. The increase in biogas production was mainly a consequence of the increase in organic loading rate. However, the differences could also be related to the synergy between both substrates and the carbon-to-nitrogen ratio. Moreover, the analysis of the macro-compounds, protein, lipids, carbohydrates and fibers, showed lower removal efficiencies in the co-digester as the microorganisms obtained nutrients from the soluble carbohydrates provided by the glycerol. The digestate stability, evaluated through a respirometric assay, showed that co-substrate addition does not exert a negative impact on digestate quality.

  19. Co-digestion of food waste in a municipal wastewater treatment plant: Comparison of batch tests and full-scale experiences.

    Science.gov (United States)

    Koch, Konrad; Plabst, Markus; Schmidt, Andreas; Helmreich, Brigitte; Drewes, Jörg E

    2016-01-01

    The effects of co-digestion of food waste in a municipal wastewater treatment plant (WWTP) were studied in batch tests. The results obtained were compared with the mass balance of a digester at a full-scale WWTP for a one-year period without and with the addition of co-substrate. The specific methane yield calculated from the balance was 18% higher than the one in the batch tests, suggesting a stimulation of methane generation by co-digestion. It was hypothesized that this increase was caused by shifting the C/N ratio of raw sludge (8.8) to a more favourable ratio of the added food waste (17.7). In addition, potential benefits by adding food waste for energy autarky was investigated. While just 25% of the total energy demand of the plant could be recovered by biogas generation when no co-substrate was fed, this percentage has more than doubled when food waste was added at a ratio of 10% (w/w).

  20. Modelling the Kinetics of Biogas Production from Mesophilic Anaerobic Co-Digestion of Cow Dung with Plantain Peels

    Directory of Open Access Journals (Sweden)

    Ganiyu Kayode Latinwo

    2015-02-01

    Full Text Available This work investigated the effect of plantain peels as co-substrate in the anaerobic digestion of cow dung for efficient and high biogas production. The biogas experiments were carried out in two different 5 L anaerobic digesters and incubated for 40 days at ambient mesophilic temperatures (28 oC to 34 °C. The results showed that co-digestion of cow dung with plantain peels as co-substrate reduced start-up time for biogas generation and increased biogas yield by 18% as compared to cow dung alone. Peak biogas production was obtained for both digesters at pH of 6.7 and 6.9 as well as temperature of 29 and 30oC, respectively. Modelling study revealed that exponential plot simulated better in both ascending and descending limb than the linear plot the biogas production rates in biogas production from cow dung co-digested with plantain peels and cow dung alone, respectively. Logistic growth model and modified Gompertz plot showed better correlation of cumulative biogas production than exponential rise to maximum plot. These results show that biogas production can be enhanced efficiently through co-digestion process.

  1. Anaerobic biodegradation of linear alkylbenzene sulfonate (LAS) in upflow anaerobic sludge blanket (UASB) reactors.

    Science.gov (United States)

    Sanz, José L; Culubret, Elayne; de Ferrer, Juan; Moreno, Alfonso; Berna, José L

    2003-01-01

    The anaerobic biodegradation of Linear Alkylbenzene Sulfonate (LAS) was studied in Upflow Anaerobic Sludge Blanket Reactors (UASB). One reactor was fed with easily degradable substrates and commercial LAS solution during a period of 3 months (Reactor 1), meanwhile a second reactor was fed with a commercial LAS solution without co-substrate (Reactor 2) during 4 months. Both reactors were operated with an organic loading rate of 4-5 mg-LAS/l x day and a hydraulic retention time of one day. The LAS biodegradation was determined by full mass balance. LAS was analysed by HPLC in the liquid phase (influent and effluent streams of the reactors) as well as in the solid phase (granular sludge used as biomass). The results indicate a high level of removal (primary biodegradation: 64-85%). Biodegradation was higher in the absence of external co-substrates than in the presence of additional sources of carbon. This indicates that the surfactant can be partially used as carbon and energy source by anaerobic bacteria. Under the operating conditions used, inhibition of the methanogenic activity or any other negative effects on the biomass due to the presence of LAS were not observed. The methanogenic activity remained high and stable throughout the experiment.

  2. Examination of food waste co-digestion to manage the peak in energy demand at wastewater treatment plants.

    Science.gov (United States)

    Lensch, D; Schaum, C; Cornel, P

    2016-01-01

    Many digesters in Germany are not operated at full capacity; this offers the opportunity for co-digestion. Within this research the potentials and limits of a flexible and adapted sludge treatment are examined with a focus on the digestion process with added food waste as co-substrate. In parallel, energy data from a municipal wastewater treatment plant (WWTP) are analysed and lab-scale semi-continuous and batch digestion tests are conducted. Within the digestion tests, the ratio of sewage sludge to co-substrate was varied. The final methane yields show the high potential of food waste: the higher the amount of food waste the higher the final yield. However, the conversion rates directly after charging demonstrate better results by charging 10% food waste instead of 20%. Finally, these results are merged with the energy data from the WWTP. As an illustration, the load required to cover base loads as well as peak loads for typical daily variations of the plant's energy demand are calculated. It was found that 735 m³ raw sludge and 73 m³ of a mixture of raw sludge and food waste is required to cover 100% of the base load and 95% of the peak load.

  3. Illumina sequencing-based analyses of bacterial communities during short-chain fatty-acid production from food waste and sewage sludge fermentation at different pH values.

    Science.gov (United States)

    Cheng, Weixiao; Chen, Hong; Yan, ShuHai; Su, Jianqiang

    2014-09-01

    Short-chain fatty acids (SCFAs) can be produced by primary and waste activated sludge anaerobic fermentation. The yield and product spectrum distribution of SCFAs can be significantly affected by different initial pH values. However, most studies have focused on the physical and chemical aspects of SCFA production by waste activated sludge fermentation at different pH values. Information on the bacterial community structures during acidogenic fermentation is limited. In this study, comparisons of the bacterial communities during the co-substrate fermentation of food wastes and sewage sludge at different pH values were performed using the barcoded Illumina paired-end sequencing method. The results showed that different pH environments harbored a characteristic bacterial community, including sequences related to Lactobacillus, Prevotella, Mitsuokella, Treponema, Clostridium, and Ureibacillus. The most abundant bacterial operational taxonomic units in the different pH environments were those related to carbohydrate-degrading bacteria, which are associated with constituents of co-substrate fermentation. Further analyses showed that during organic matter fermentation, a core microbiota composed of Firmicutes, Proteobacteria, and Bacteroidetes existed. Comparison analyses revealed that the bacterial community during fermentation was significantly affected by the pH, and that the diverse product distribution was related to the shift in bacterial communities.

  4. Performance of mesophilic biohydrogen-producing cultures at thermophilic conditions.

    Science.gov (United States)

    Gupta, Medhavi; Gomez-Flores, Maritza; Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Hesham El Naggar, M; Nakhla, George

    2015-09-01

    In this study, batch tests were conducted to investigate the performance of mesophilic anaerobic digester sludge (ADS) at thermophilic conditions and estimate kinetic parameters for co-substrate fermentation. Starch and cellulose were used as mono-substrate and in combination as co-substrates (1:1 mass ratio) to conduct a comparative assessment between mesophilic (37 °C) and thermophilic (60 °C) biohydrogen production. Unacclimatized mesophilic ADS responded well to the temperature change. The highest hydrogen yield of 1.13 mol H2/mol hexose was observed in starch-only batches at thermophilic conditions. The thermophilic cellulose-only yield (0.42 mol H2/mol hexose) was three times the mesophilic yield (0.13 mol H2/mol hexose). Interestingly, co-fermentation of starch-cellulose at mesophilic conditions enhanced the hydrogen yield by 26% with respect to estimated mono-substrate yields, while under thermophilic conditions no enhancement in the overall yield was observed. Interestingly, the estimated overall Monod kinetic parameters showed higher rates at mesophilic than thermophilic conditions.

  5. Biogas production from spent rose hips (Rosa canina L.): fraction separation, organic loading and co-digestion with N-rich microbial biomass.

    Science.gov (United States)

    Osojnik Črnivec, Ilja Gasan; Muri, Petra; Djinović, Petar; Pintar, Albin

    2014-11-01

    Complex waste streams originating from extraction processes containing residual organic solvents and increased C/N ratios have not yet been considered as feedstock for biogas production to a great extent. In this study, spent rosehip (Rosa canina L.) solid residue (64%VS, 22 MJ/kg HHV, 30C/1N) was obtained from an industrial ethanol aided extraction process, and extensively examined in an automated batch bioreactor system for biogas production. Fraction separation of the compact lignocellulosic seeds increased the available sugar and ethanol content, resulting in high biogas potential of the sieved residue (516 NL/kg VS'). In co-digestion of spent rosehip substrate with non-deactivated nitrogen rich microbial co-substrates, methanogenesis was favored (Y(m) > 68%(CH4)). In individual digestion of microbial co-substrates, this was not the case, as biogas with 28 vol.% N2 was produced from activated sludge supplement. Therefore, effective inhibition of exogenous microbiota was achieved in the presence of carbonaceous spent rose hip.

  6. Purification and properties of a secondary alcohol dehydrogenase from the parasitic protozoan Tritrichomonas foetus.

    Science.gov (United States)

    Kleiner, D E; Johnston, M

    1985-07-05

    A novel secondary alcohol dehydrogenase has been isolated from Tritrichomonas foetus, the protozoan parasite which is responsible for bovine trichomonal abortion. The enzyme has been obtained in apparently homogeneous form after a 120-fold purification from cell homogenates, thus indicating that this activity constitutes an unusually high 1% of the total cytosolic protein. The native Mr = 115,000, determined by polyacrylamide gel electrophoresis. Mobility on sodium dodecyl sulfate gels suggests that the enzyme is composed of 6-8 subunits, identical as to molecular size (Mr = 17,000). The enzyme catalyzes the reversible oxidation of 2-propanol to acetone, using NADP+ (and not NAD+) as the redox-active co-substrate. Other small secondary alcohols, such as 2-butanol, 2- and 3-pentanol, cyclobutanol, and cyclopentanol are substrates, as are the corresponding ketones of these alcohols. Primary alcohols, such as ethanol and 1-propanol, are oxidized at rates less than 5% of that observed for 2-propanol. Product inhibition studies demonstrate an ordered kinetic mechanism, wherein the co-substrate (NADP+/NADPH) binds to the enzyme prior to binding of the substrate (alcohol/ketone).

  7. Pressure combustion of Rhenish brown coal. Final report; Druckkohlenstaubverbrennung von rheinischer Braunkohle. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ayar, A.; Fielenbach, C.; Gross, R.; Holfeld, T.; Lockemann, S.; Severin, C.; Thulfaut, C.; Hillemacher, B.

    2003-07-01

    konnte, haben vom Lehrstuhl durchgefuehrte NO{sub x}-Messungen an der DKSF-Anlage Dorsten im Schmelzkammerfeuerungsbetrieb mit der Steinkohle Spitzbergen zwischen 9 und 13 bar ein Absinken der Stickoxidkonzentrationen mit steigendem Druck ergeben. Fuer die rheinische Braunkohle soll dieser Druckeinfluss in den naechsten Versuchsfahrten ausfuehrlicher untersucht werden. Es wurde anhand von numerischen Simulationen zu einer Braunkohleflamme der 6. Versuchsfahrt ein Vergleich zwischen der NO{sub x}-Modellierung im Standard-FLUENT-Code und in dem mit User Defined Subroutines der international flame research foundation (IFRF), Ijmuiden, erweiterten FLUENT-Code vorgenommen. Es zeigte sich, dass bei der Modellierung der Stickoxidbildung die unterschiedlich vorhergesagten Flammentemperaturen eine entscheidende Rolle spielen. Eine genauere Analyse der NO{sub x}-Modelle im Vergleich zu Messergebnissen ist bei einer Schmelzkammerfeuerung mit einer stabilen Flamme vorzunehmen. Es wurden zusaetzlich Messungen zur Untersuchung der Kinetik homogener Gasphasenreaktionen in Rauchgasen an einem Stahlreaktor durchgefuehrt. Dabei wurde sowohl der thermisch bedingte als auch der durch zudosierte Additive katalysierte Abbau nitroser Komponenten betrachtet. Vergleichend wurden mit einem am Lehrstuhl entwickelten Programm die Kinetik beschrieben. Hierbei wird mit einer Sensitivitaetsanalyse eine Reduzierung der detaillierten Darstellung der Reaktionskinetik erreicht, die es erlaubt, mit einem CFD-Code wie FLUENT zwei- und dreidimensionale Rechnungen zum Abbau verschiedener Rauchgaskomponenten durchzufuehren. Die Uebereinstimmung zwischen ein- und zweidimensionalen Rechnungen und den Messungen ist gut. (orig.)

  8. Zellträgersysteme

    Science.gov (United States)

    Eckert, Karl-Ludwig; Blum, Janaki; Wintermantel, Erich

    Mit Zellträgersystemen soll dem in der klinischen Medizin vordringlichen Problem der Behandlung von schwerstkranken Patienten, die ein partielles oder totales Organversagen erleiden, abgeholfen werden. Man stellt sich vor, dass durch geeignete Trägersubstanzen und -strukturen die Übertragung von metabolisch aktiven Zellen von einem Organismus auf den andern, erkrankten Organismus möglich wird. Die Funktion des Zellträgers ist dabei in erster Linie die des Abstandhalters einzelner Zellen und des Offenhalters für Versorgungskanäle. Man geht von der Vorstellung aus, dass Zellen, die einen optimalen Stoffwechsel haben sollen, in definierten Abständen zueinander in einem Zellträger angeordnet sein sollen. Dabei spielt die Vorstellung eine Rolle, mit dem Trägerwerkstoff die Struktur des zu ersetzenden Organs zu imitieren (Werkstoff-Mimikry). Erste Zellträgersysteme, die im Tierversuch eingesetzt wurden und sich derzeit in Vorbereitung zur klinischen Applikation befinden, sind Pankreas-Ersatzsysteme [1]. Diese Zelltransplantate basieren häufig auf Polymermembranen, die den Empfängerorganismus von den transplantierten allo- oder xenogenen Zellen trennen. Dabei verhindert die Membran einen Kontakt des Empfängerorganismus mit den Proteinen der transplantierten Zellen und damit eine Abstossungsreaktion. Es ist bei dieser Technologie zu bedenken, dass Polymere im Körper einem hydrolytischen Abbau unterworfen sein können und damit die Dauerbeständigkeit einer Polymermembran in Frage gestellt ist. Diesem Aspekt kann Rechnung getragen werden, indem Zellträgersysteme, die immunoprotektive Membranen nach bestimmten Verweilzeiten im Körper samt den transplantierten Zellen ausgetauscht werden.

  9. Noble metal recycling. Project 2: Optimization of discontinuous thermal processes (emission reduction). Final report; Edelmetallrecycling. Teilvorhaben 2: Weiterentwicklung der Verfahrenstechnik bei diskontinuierlichen thermischen Prozessen (Emissionsminderung). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Baumbach, G.; Berger, R.

    2000-10-01

    . Waehrend der Katalysator im Reingas die erwartete Zuverlaessigkeit beim PCDD/PCDF Abbau zeigte konnte im Rohgas wegen der Staubbeladung kein zuverlaessiger Betrieb erreicht werden. Da eine Wiederaufheizung der Reingase wirtschaftlich nicht tragbar ist, eignet sich das Verfahren nicht fuer diesen Prozess. (orig.)

  10. Biogeochemical investigations on processes affecting the transport behaviour of trace elements in the tidal Elbe River; Biogeochemische Prozessuntersuchungen zum Transportverhalten von Spurenelementen in der Tide-Elbe

    Energy Technology Data Exchange (ETDEWEB)

    Hennies, K. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Gewaesserphysik

    1997-12-31

    This work concentrates on distribution and transport of micropollutants in anthropogenically affected estuary systems. Choosing the tidal Elbe River as an example, the influence of microlagae on two important partial processes of the transport regime, the remobilization (a) from undisturbed sediments and (b) from suspended particulate matter, was simulated and quantified in the laboratory. Benthic and planktonic release of Cd, Cu, Pb and Zn into the dissolved phase of the river pelagial were estimated and comparatively evaluated for summer/late summer situation. During that season natural decomposition of suspended particulate matter in the water column thus represents the quantitatively most significant mobilization pathway for particle bound heavy metals in the river section between Hamburg and Glueckstadt. Knowing the composition and heavy metal load of suspended particulate matter, rich in algae, mobilization rates can consequently be calculated for the water column with regard to conditions typical for estuaries. The prognosis of the differing transport behaviour of single heavy metals for greater sections of estuaries is also possible if these rates are implemented into transport-reaction models. (orig.) [Deutsch] Die vorliegende Arbeit befasst sich mit Verteilung und Transport von Spurenschadstoffen in anthropogen belasteten Aestuarsystemen. Am Beispiel der Tide-Elbe wurde der Einfluss von Mikroalgen auf zwei wichtige Teilprozesse des Transportregimes, die Remobilisierung (a) aus ungestoerten Sedimenten und (b) aus suspendierten Schwebstoffen, im Labor simuliert und quantifiziert. Benthische und planktische Freisetzung von Cd, Cu, Pb und Zn in die Loesungsphase des Flusspelagials der Tide-Elbe wurden fuer die Sommer-/Spaetsommer-Situation abgeschaetzt und vergleichend bewertet. Der natuerliche Schwebstoff-Abbau in der Wassersaeule stellt demnach in dieser Jahreszeit im Stromabschnitt zwischen Hamburg und Glueckstadt den quantitativ bedeutsamsten

  11. Use of natural gas for brine-based winning and processing methods in Bleicherode, Thuringia; Erdgaseinsatz fuer soltechnische Gewinnungs- und Verarbeitungsverfahren in Bleicherode/Thueringen

    Energy Technology Data Exchange (ETDEWEB)

    Richter, M. [Gasversorgung Thueringen GmbH, Erfurt (Germany); Grabe, A. [Energiegesellschaft Bleicherode mbH (Germany)

    1999-10-01

    Mining of potassium in Bleicherode started around the turn of the century with the sinking of the first production shafts. Following exhaustion of the hard salt reverses, production was converted in the early seventies to carnallite, a double salt consisting of potassium chloride and magnesium chloride. A new winning and processing technology was developed to permit the use of carnallite. Mining is accomplished by means of brining, a selective hot-extraction method. The thermal energy necessary for this purpose and for further processing of the carnallite is generated together with the necessary process electricity in a co-generation plant constructed primarily specifically for these processes. The central element of this unit-type co-generation plant consists of two gas-engine/generator sets, which are operated monovalently using natural gas H, and two steam-generators, in which both natural gas H and light fuel oil are used. (orig.) [German] Der Kalibergbau begann mit dem Teufen der ersten Kalischaechte um die Jahrhundertwende. Nach Ausschoepfen der Hartsalzvorraete wurde die Produktion Anfang der 70er Jahre auf Carnallitit, einem Doppelsalz aus Kaliumchlorid und Magnesiumchlorid, umgestellt. Fuer den Einsatz von Carnallitit wurde eine neue Gewinnungs- und Verarbeitungstechnologie entwickelt. Durch Solung, einem selektiven Heissloeseverfahren, erfolgt der Abbau. Die dafuer sowie fuer die weitere Verarbeitung des Carnallitit erforderliche Waermeenergie und der Prozessstrom werden in einem vorrangig fuer diese Prozesse errichtetem Heizkraftwerk erzeugt. Kernstueck der BHKW-Anlage sind zwei Gasmotor-Generator-Einheiten, die monovalent mit Erdgas H betrieben werden sowie zwei Dampferzeuger, in denen sowohl Erdgas H als auch leichtes Heizoel zum Einsatz kommt. (orig.)

  12. Structure dynamics with regard to non-linear support behavior; Dynamische Strukturberechnung unter Beruecksichtigung nichtlinearen Lagerverhaltens

    Energy Technology Data Exchange (ETDEWEB)

    Driessen, W. [Technischer Ueberwachungs-Verein Nord e.V., Hamburg (Germany)

    2000-07-01

    Because of modifications to a feed-water line of a power plant structural calculations of the pipework were performed. As a result of a linear (modal) analysis very high restraint forces on the supports were calculated. In order to reduce conservatisms in the calculation the model was optimized with regard to the support stiffnesses and nonlinear behavior of slide bearings, guides and shock absorbers were taken into account. The main result of the non-linear analysis, which was performed by methods of direct-integration, was that nonlinearity yields evident differences in structural frequencies and in energy dissipation (damping) in comparison to the linear analysis. The high restraint forces on the supports became smaller for most of the supports but at some points the forces of the non-linear analysis were even higher. So the conservatism of the linear analysis is not fully valid for the whole structure. The relevance of the non-linear effects in dynamic piping calculations is shown by comparing the calculation result with measurements which were performed on structures in the plant. (orig.) [German] Im Rahmen der Aenderung der Speisewasserleitung einer Kraftwerksanlage wurde die Struktur neu berechnet. Die Analysen mit einem linearen Modell (modal), das ueblicherweise verwendet wird, ergaben hohe Lasten an Halterungen. Zum Abbau von Konservativitaeten wurde eine realistischere Modellierung durch die Beruecksichtigung des nichtlinearen Verhaltens der in der Anlage befindlichen Gleitlager, Fuehrungen und Stossbremsen in der Berechnung vorgenommen. Die Untersuchungen haben ergeben, dass durch die Nichtlinearitaet das Frequenzverhalten der Struktur und die Dissipation von Energie durch Reibvorgaenge wesentlich beeinflusst werden. Des Weiteren ist festzustellen, dass aus linearen Analysen nicht uneingeschraenkt konservative Ergebnisse gewonnen werden. Die Relevanz der Beruecksichtigung des nichtlinearen Lagerverhaltens bei einer dynamischen Strukturberechnung wird

  13. Decommissioning and dismantling: Qualification of the gamma scanning method as a certified method for radiological decontrolling measurement. Final report; Stillegung und Rueckbau: Qualifizierung des Gamma-Scanning zur Freimessung. Genehmigungspraxis. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kirchhoff, J.; Stasch, W.P.

    1998-10-01

    auch die `Fehlerquelle Mensch` ausgeschlossen werden. Mit dem Gamma-Scanning soll ein Freimessverfahren realisiert werden, das den Nachweis der Unterschreitung festgelegter radiologischer Grenzwerte insbesondere fuer die beim Abbau zuletzt verbleibenden leeren Gebaeude sicherstellt. Gegenueber den herkoemmlichen Freimessverfahren soll durch die Art der Messung (Gammastrahlungsmessung) ein umfassender Nachweis auch bis in Tiefen von einigen Zentimetern erreicht werden. (orig.)

  14. Use of soluble humic substances as solubilisers in the in situ rehabilitation of sites contaminated with PAH or longchain hydrocarbons from crude oil. Final report; Einsatz von loeslichen Huminstoffen als Loesungsvermittler bei der In-situ-Sanierung von PAK- und laengerkettigen Mineraloelkohlenwasserstoff-Schadensfaellen. Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Koerdel, W.; Kloeppel, H. [Fraunhofer-Institut fuer Umweltchemie und Oekotoxikologie, Schmallenberg (Germany); Gohlke, U. [Fraunhofer-Institut fuer Angewandte Polymerforschung, Teltow (Germany); Schulz-Berendt, V.; Koopmann [Umweltschutz Nord GmbH, Ganderkesee (Germany)

    1999-12-14

    The purpose of the present project was to demonstrate in example model experiments the suitability of DOM solutions, which can easily be derived from composts, for in situ rehabilitation and to compare the success achieved with remediation results obtained using surfactants and coffeein. The model experiments were carried out according to the DECHEMA guide to ''Laboratory methods for assessing biological soil rehabilitation'' using glass columns (of 14 cm dia. and 60 cm length) containing one of two different PAH-contaminated soils (PAH I and PAH II) or a soil contaminated with crude oil hydrocarbons (CHC). Altogether a markedly enhanced leaching of pollutants (PAH and CHC) from the soils as well as an increased degradation of contaminants was observed during the experiments, and there were no negative accompanying processes such as excessive bacterial growth, occlusion of soil pores or excessive accumulation of DOM in the soil. In terms of posing a hazard to groundwater natural humic substances are certainly to be viewed as less critical than synthetic detergents. [German] Ziel des Vorhabens war es, die Eignung von DOM-Loesungen, die aus Komposten leicht gewonnen werden koennen, in der In-situ-Sanierung exemplarisch anhand von Modellversuchen aufzuzeigen und den erzielten Sanierungserfolg mit dem von Tensiden und Coffein zu vergleichen. Die Modelluntersuchungen erfolgten gemaess DECHEMA-Leitfaden 'Labormethoden zur Beurteilung der biologischen Bodensanierung' unter Verwendung von Glassaeulen (14 cm diameter, 60 cm Laenge) mit zwei PAK-belasteten Boeden (PAK I und PAK II) sowie einem mit Mineraloelkohlenwasserstoffen belasteten Boden (MKW-Boden). Insgesamt konnte mit natuerlichen DOM-Loesungen eine deutlich gesteigerte Auswaschung der Schadstoffe (PAK und MKW) aus den Boeden waehrend des Versuchs als auch ein gesteigerter Abbau der Kontaminanten erreicht werden, ohne dass negative Begleitprozesse wie zu starkes Bakterienwachstum und

  15. Hot gas filtration: Investigations to remove gaseous pollutant components out of flue gas during hot gas filtration. Final report; HGR: Untersuchung zur Minimierung von gasfoermigen Schadstoffen aus Rauchgasen bei der Heissgasfiltration. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Christ, A.; Gross, R.; Renz, U.

    1998-07-01

    Power plants with gas and steam turbines in pressurized fluidized bed or pressurized gasification processes enable power generation of coal with high efficiency and little emissions. To run these plants the cleaning of the flue gas is necessary before entering the turbines under the conditions of high temperature and pressure. Ceramic filter elements are the most probable method for hot gas cleaning. A simultaneous reduction of gaseous pollutant components under these conditions could help to make the whole process more efficient. The aim of the project is to integrate the catalytic reduction of carbon monoxide, hydrocarbons and nitric oxides into the hot gas filtration with ceramic filter elements as a one step mecanism. The project is focused on: - the catalytic behaviour of ferruginous ashes of brown coal, - the effectiveness of calcinated aluminates as a catalyst to remove uncombusted hydrocarbons in a hot gas filtration unit, - numerical simulation of the combined removal of particles and gaseous pollutant components out of the flue gas. (orig.) [Deutsch] Gas- und Dampfturbinen-Kraftwerke mit Druckwirbelschicht- oder mit Druckvergasungsverfahren ermoeglichen die Verstromung von Kohle mit hohem Wirkungsgrad und niedrigen Emissionen. Eine Voraussetzung fuer den Betrieb dieser Anlagen ist die Entstaubung der Rauchgase bei hohen Temperaturen und Druecken. Abreinigungsfilter mit keramischen Elementen werden dazu eingesetzt. Eine Reduzierung gasfoermiger Schadstoffe unter den gleichen Bedingungen koennte die Rauchgaswaesche ersetzen. Ziel des Gesamtvorhabens ist es, die Integration von Heissgasfiltration und katalytischem Abbau der Schadstoffe Kohlenmonoxid, Kohlenwasserstoffe und Stickoxide in einem Verfahrensschritt zu untersuchen. Die Arbeitsschwerpunkte dieses Teilvorhabens betreffen - die katalytische Wirkung eisenhaltiger Braunkohlenaschen, - die Wirksamkeit des Calciumaluminats als Katalysator des Abbaus unverbrannter Kohlenwasserstoffe im Heissgasfilter

  16. Chemistry enters nucleic acids biology: enzymatic mechanisms of RNA modification.

    Science.gov (United States)

    Boschi-Muller, S; Motorin, Y

    2013-12-01

    Modified nucleotides are universally conserved in all living kingdoms and are present in almost all types of cellular RNAs, including tRNA, rRNA, sn(sno)RNA, and mRNA and in recently discovered regulatory RNAs. Altogether, over 110 chemically distinct RNA modifications have been characterized and localized in RNA by various analytical methods. However, this impressive list of known modified nucleotides is certainly incomplete, mainly due to difficulties in identification and characterization of these particular residues in low abundance cellular RNAs. In DNA, modified residues are formed by both enzymatic reactions (like DNA methylations, for example) and by spontaneous chemical reactions resulting from oxidative damage. In contrast, all modified residues characterized in cellular RNA molecules are formed by specific action of dedicated RNA-modification enzymes, which recognize their RNA substrate with high specificity. These RNA-modification enzymes display a great diversity in terms of the chemical reaction and use various low molecular weight cofactors (or co-substrates) in enzymatic catalysis. Depending on the nature of the target base and of the co-substrate, precise chemical mechanisms are used for appropriate activation of the base and the co-substrate in the enzyme active site. In this review, we give an extended summary of the enzymatic mechanisms involved in formation of different methylated nucleotides in RNA, as well as pseudouridine residues, which are almost universally conserved in all living organisms. Other interesting mechanisms include thiolation of uridine residues by ThiI and the reaction of guanine exchange catalyzed by TGT. The latter implies the reversible cleavage of the N-glycosidic bond in order to replace the initially encoded guanine by an aza-guanosine base. Despite the extensive studies of RNA modification and RNA-modification machinery during the last 20 years, our knowledge on the exact chemical steps involved in catalysis of RNA

  17. Valorisation of used cooking oil sludge by codigestion with swine manure

    Energy Technology Data Exchange (ETDEWEB)

    Fierro, J.; Martínez, E.J.; Morán, A.; Gómez, X., E-mail: xagomb@unileon.es

    2014-08-15

    Highlights: • Anaerobic codigestion of UCO sludge and swine manure was successful at 50 d HRT. • VFA build-up was present during the reactor start-up but were reduced after 50 d. • CH{sub 4} yield was 326 l/kg VS{sub feed}, decreasing HRT to 30 d resulted in poor performance. • Digestate at 50 d HRT was unstable although the load applied to the reactor was low. - Abstract: The addition of lipid wastes to the digestion of swine manure was studied as a means of increasing biogas production. Lipid waste was obtained from a biodiesel plant where used cooking oil is the feedstock. Digestion of this co-substrate was proposed as a way of valorising residual streams from the process of biodiesel production and to integrate the digestion process into the biorefinery concept. Batch digestion tests were performed at different co-digesting proportions obtaining as a result an increase in biogas production with the increase in the amount of co-substrate added to the mixture. Semi-continuous digestion was studied at a 7% (w/w) mass fraction of total solids. Co-digestion was successful at a hydraulic retention time (HRT) of 50 d but a decrease to 30 d resulted in a decrease in specific gas production and accumulation of volatile and long chain fatty acids. The CH{sub 4} yield obtained was 326 ± 46 l/kg VS{sub feed} at an HRT of 50 d, while this value was reduced to 274 ± 43 l/kg VS{sub feed} when evaluated at an HRT of 30 d. However these values were higher than the one obtained under batch conditions (266 ± 40 l/kg VS{sub feed}), thus indicating the need of acclimation to the co-substrate. Despite of operating at low organic loading rate (OLR), measurements from respirometry assays of digestate samples (at an HRT of 50 d) suggested that the effluent could not be directly applied to the soil as fertiliser and might have a negative effect over soil or crops.

  18. Asymmetric Synthesis of(S)-acetoin by Reduction of 2,3-Diacetyl with Resting Cells%面包酵母还原丁二酮合成(S)-乙偶姻的研究

    Institute of Scientific and Technical Information of China (English)

    刘培海; 谢能中; 卢志晓; 胡萌; 宋卫德; 孙灿; 李明明; 杨立明

    2013-01-01

    (S)-acetoin was synthesized selectively using diacetyl as substrate and baker yeast resting cells as reductase. The effect of bacteria, cosubstrate, cosubstrate concentration, pH of buffer system and enzyme inhibitors on the transformation of diacetyl and ee value of (S)-acetoin was studied. The result showed the optimal conditions were:Saccharomyces cerevisiae XG-4-2, cosubstrate (ethanol)30 g/L, buffer system:0.05 mol/L Na2HPO4-KH2PO4 (pH5.0), substrate 2 g/L, enzyme inhibitor (isopropanol) 2 g/L. The transformation rate of diacetyl was 82 %, in which(S)-acetoin was covered with 91.2%and ee value of(S)-acetoin was 82.4%.%以丁二酮(Diacetyl)为底物,以面包酵母(Saccharomyces cerevisiae)休止细胞为还原剂,选择性合成(S)-乙偶姻。分别考察了不同菌株、辅助底物、辅助底物浓度、缓冲液体系pH值和酶抑制剂等因素对丁二酮转化率和(S)-乙偶姻ee值的影响。结果表明:丁二酮的转化(S)-乙偶姻的适宜条件为:面包酵母XG-4-2,辅助底物为30.0 g/L乙醇,0.05 mol/L pH 5.0的Na2HPO4-KH2PO4缓冲体系,酶抑制剂异丁醇加量为2.0 g/L。丁二酮转化率可达82%,(S)-乙偶姻纯度可达到91.2%,(S)-乙偶姻对映体过量值(ee值)达82.4%。

  19. Production of Cellulase from Oil Palm Biomass as Substrate by Solid State Bioconversion

    Directory of Open Access Journals (Sweden)

    Md. Z. Alam

    2005-01-01

    Full Text Available Solid state bioconversion (SSB of lignocellulosic material oil palm biomass (OPB generated from palm oil industries as waste was conducted by evaluating the enzyme production through filamentous fungus in lab-scale experiment. OPB in the form of empty fruit bunches (EFB was used as the solid substrate and treated with the fungus Trichoderma harzianum to produce cellulase. The results presented in this study revealed that the higher cellulase activity of 0.0413 unit was achieved at the day 3 of fermentation. While the optimum study indicated the enzyme production of 0.0433 unit with moisture content of 50%, 0.0413 unit with 5% v/w of inoculum size and 0.0413 unit with co-substrate concentration of 2% (w/w at days 9, 9 and 12 of fungal treatment, respectively. The parameters glucosamine and reducing sugar were observed to evaluate the growth and substrate utilization in the experiment.

  20. Biogas technology on farms 1; Biokaasuteknologiaa maatiloilla 1. Biokaasulaitoksen hankinta, kaeyttoeoenotto ja operointi - kaeytaennoen kokemuksia MTT:n maatilakohtaiselta laitokselta

    Energy Technology Data Exchange (ETDEWEB)

    Luostarinen, S. (ed.)

    2013-11-01

    Biogas technologies can be applied for several different purposes in agriculture. It is a means to utilise the energy content of manure and other organic materials, to recycle their nutrients into plant production, enhance utilisation of nitrogen and to mitigate emissions from agriculture. Of the two end-products, biogas can be utilised in the production of heat, electricity and/or vehicle fuel and digestate as fertiliser on fields. Agricultural biogas plants digest mainly animal manure in Finland. Several co-substrates are also used, including different plant biomasses and suitable by-products from especially food production. The aim of using co-substrates is usually to increase the amount of energy produced but they also affect the nutrient content and ratios in the digestate. Planning agricultural biogas plants starts from available fee materials, their amounts and characteristics. The biogas plant is designed for these materials and the technologies used are chosen to suit them. There are several options for plant design and how it can be attached into existing farm structures and it is wise to discuss these matters with an expert. In this way, correct farm-specific decisions can be made. When permitting the plant (permission for construction, environmental permit, safety issues, fertiliser legislation), it is important to make contact with the respective authority. Profitability of the biogas plant should be considered carefully. Things to consider include e.g. available financial incentives, investment cost, energy production and utilisation (own use or sale), nutrient recycling and potential avoidance of mineral fertilisers, co-substrates with gate fee, improved hygiene and less odours. Experiments at MTT Maaninka farm-scale biogas plant showed that dairy cow slurry produces 12-14 m{sup 3} of methane per ton of fresh weight. In this specific biogas plant this results potentially in methane production with an energy content of 400 MWh (3500 m{sup 3} of slurry

  1. The energy balance of utilising meadow grass in Danish biogas production

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Raju, Chitra Sangaraju; Kucheryavskiy, Sergey V.

    2015-01-01

    This paper presents a study of the energy balance of utilising nature conservation biomass from meadow habitats in Danish biogas production. Utilisation of nature conservation grass in biogas production in Denmark represents an interesting perspective for enhancing nature conservation of the open...... grassland habitats, while introducing an alternative to the use of intensively cultivated energy crops as co-substrates in manure based biogas plants. The energy balance of utilising nature conservation grass was investigated by using: data collected from previous investigations on the productivity...... of meadow areas, different relevant geo-datasets, spatial analyses, and various statistical analyses. The results show that values for the energy return on energy invested (EROEI) ranging from 1.7 to 3.3 can be obtained when utilising meadow grasses in local biogas production. The total national net energy...

  2. Optimization of biomethanation focusing on high ammonia loaded processes

    DEFF Research Database (Denmark)

    Wang, Han

    , could theoretically mitigate the ammonia inhibition problem (Angelidaki et al., 1999). Therefore, the effect of co-digestion of cattle manure with lipids (i.e. glycerol trioleate (GTO)) under high ammonia levels (5 g NH4+-N·L-1) in anaerobic continuous stirred tank (CSTR) reactors (RGTO) was assessed....... Additionally, for comparison purposes, a soluble carbohydrate (i.e. glucose) was also used as a co-substrate in an identical CSTR reactor (RGLU). At 5 g NH4+-N·L-1, relative methane production of RGTO and RGLU, was 10.5% and 41% compared to the expected uninhibited production, respectively. At the same time...... control reactor (RCTL), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, the hypothesis that the co-digestion of manure with lipids could alleviate the ammonia inhibition was not supported by the results. However, an “ammonia-LCFA synergetic inhibitory effect...

  3. Seed storage oil catabolism: a story of give and take.

    Science.gov (United States)

    Theodoulou, Frederica L; Eastmond, Peter J

    2012-06-01

    The transition from seed to seedling is an important step in the life cycle of plants, which is fuelled primarily by the breakdown of triacylglycerol (TAG) in 'oilseed' species. TAG is stored within cytosolic oil bodies, while the pathway for fatty acid β-oxidation resides in the peroxisome. Although the enzymology of fatty acid β-oxidation has been relatively well characterised, the processes by which fatty acids are liberated from oil bodies and enter the peroxisome are less well understood and, together with metabolite, cofactor and co-substrate transporters, represent key targets for future research in order to understand co-ordination of peroxisomal metabolism with that of other subcellular compartments.

  4. Grass as a C booster for manure-biogas in Estonia

    DEFF Research Database (Denmark)

    Pehme, Sirli; Hamelin, Lorie; Veromann, Eve

    2014-01-01

    The aim of this study was to assess the environmental consequences of using grass (from both unused and cultivated boreal grasslands) as a co-substrate to dairy cow manure for biogas production. Environmental impact categories assessed were global warming, acidification and nutrient enrichment...... (distinguishing between N and P). Scenarios studied were: traditional management of dairy cow manure, monodigestion of manure, manure co-digestion with reed canary grass and manure co-digestion with residual grass from semi-natural grasslands. The latter scenario showed the best environmental performance...... for the global warming category, for other categories it did not show clear benefits. Using reed canary grass specially produced for biogas purpose resulted in a climate change impact just as big as the reference manure management, mainly as a result of indirect land use changes. Increased impacts also occurred...

  5. Lipase-Catalyzed Production of 6-O-cinnamoyl-sorbitol from D-sorbitol and Cinnamic Acid Esters.

    Science.gov (United States)

    Kim, Jung-Ho; Bhatia, Shashi Kant; Yoo, Dongwon; Seo, Hyung Min; Yi, Da-Hye; Kim, Hyun Joong; Lee, Ju Hee; Choi, Kwon-Young; Kim, Kwang Jin; Lee, Yoo Kyung; Yang, Yung-Hun

    2015-05-01

    To overcome the poor properties of solubility and stability of cinnamic acid, cinnamate derivatives with sugar alcohols were produced using the immobilized Candida antarctica lipase with vinyl cinnamate and D-sorbitol as substrate at 45 °C. Immobilized C. antarctica lipase was found to synthesize 6-O-cinnamoyl-sorbitol and confirmed by HPLC and (1)H-NMR and had a preference for vinyl cinnamate over other esters such as allyl-, ethyl-, and isobutyl cinnamate as co-substrate with D-sorbitol. Contrary to D-sorbitol, vinyl cinnamate, and cinnamic acid, the final product 6-O-cinnamoyl-sorbitol was found to have radical scavenging activity. This would be the first report on the biosynthesis of 6-O-cinnamoyl-sorbitol with immobilized enzyme from C. antarctica.

  6. Investigation of te development of the optimal process of fermentation of grass silage by means of a two-stage process; Untersuchungen zur Entwicklung eines optimalen Verfahrens der Vergaerung von Grassilage durch zweiphasige Prozessfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H.; Jungbluth, T. [Hohenheim Univ., Stuttgart (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen, Baden-Wuerttemberg

    2007-07-01

    At present, mainly biogas plants with liquid manure as basis substrate are operated in the Federal Republic of Germany. Since the introduction of the Renewable Energy Resources Act in the year 2004, regenerating raw materials dominate as co-substrate beside organic residual substances. In the context of the composite material ''Biogas Crops network '', the mono fermentation is examined of grass silage in a two-phase procedure guidance using bioleaching. Thus the turnover rate of the energy stored in the organic mass is to be increased to methane. The focus of the investigations lies on the improvement of the hydrolysis achievement. Despite the high methane formation in the hydrolysis stage, in the thermophilic hydrolysis the highest degree of degradation of oTS and the highest yields of methane are received in the overall system.

  7. [Biodegradation of Cellulose-Containing Substrates by Micromycetes Followed by Bioconversion into Biogas].

    Science.gov (United States)

    Prokudina, L I; Osmolovskii, A A; Egorova, M A; Malakhova, D V; Netrusov, A I; Tsavkelova, E A

    2016-01-01

    The ability of micromycetes Trichoderma viride and Aspergillus terreus to decompose the cellulose-containing substrates was studied. Office paper and cardboard, as well as a paper mixture, were found to be the most hydrolyzable. The cellulolytic activity of T. viride was 2-3 times higher than that of A. terreus; the highest values of 0.80 and 0.73 U/mLwere obtained from office paper and the paper mixture, respectively. The micromycete cultivation conditions (composition of culture medium, sucrose cosubstrate addition, seeding method) and the conditions of the fungus biomass treatment for its subsequent bioconversion into biogas by anaerobic microbial communities were optimized. It was shown that pretreatment improves the efficiency of biogas production from lignocellulosic materials under seeding with microbial community of bovine animal manure. After pretreatment of the Jerusalem artichoke phytomass (stems and leaves) and its subsequent bioconversion into biogas by methanogenic community, the biogas yield was increased by 1.5 times.

  8. Crystal Structures of the Glycopeptide Sulfotransferase Teg12 in a Complex with the Teicoplanin Aglycone

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Matthew J.; Banik, Jacob J.; Darst, Seth A.; Brady, Sean F. (Rockefeller)

    2010-06-25

    The TEG gene cluster, a glycopeptide biosynthetic gene cluster that is predicted to encode the biosynthesis of a polysulfated glycopeptide congener, was recently cloned from DNA extracted directly from desert soil. This predicted glycopeptide gene cluster contains three closely related sulfotransferases (Teg12, -13, and -14) that sulfate teicoplanin-like glycopeptides at three unique sites. Here we report a series of structures: an apo structure of Teg12, Teg12 bound to the desulfated cosubstrate 3{prime}-phosphoadenosine 5{prime}-phosphate, and Teg12 bound to the teicoplanin aglycone. Teg12 appears to undergo a series of significant conformational rearrangements during glycopeptide recruitment, binding, and catalysis. Loop regions that exhibit the most conformational flexibility show the least sequence conservation between TEG sulfotransferases. Site-directed mutagenesis guided by our structural studies confirmed the importance of key catalytic residues as well as the importance of residues found throughout the conformationally flexible loop regions.

  9. Structural Determinants of Clostridium difficile Toxin A Glucosyltransferase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Pruitt, Rory N.; Chumbler, Nicole M.; Rutherford, Stacey A.; Farrow, Melissa A.; Friedman, David B.; Spiller, Ben; Lacy, D. Borden (Vanderbilt)

    2012-03-28

    The principle virulence factors in Clostridium difficile pathogenesis are TcdA and TcdB, homologous glucosyltransferases capable of inactivating small GTPases within the host cell. We present crystal structures of the TcdA glucosyltransferase domain in the presence and absence of the co-substrate UDP-glucose. Although the enzymatic core is similar to that of TcdB, the proposed GTPase-binding surface differs significantly. We show that TcdA is comparable with TcdB in its modification of Rho family substrates and that, unlike TcdB, TcdA is also capable of modifying Rap family GTPases both in vitro and in cells. The glucosyltransferase activities of both toxins are reduced in the context of the holotoxin but can be restored with autoproteolytic activation and glucosyltransferase domain release. These studies highlight the importance of cellular activation in determining the array of substrates available to the toxins once delivered into the cell.

  10. CULTIVATION OF P. FLORIDA SUPLEMENTED OF RICE BRAIN ON BEECH WOOD WASTE

    Directory of Open Access Journals (Sweden)

    Hüseyin SİVRİKAYA

    1998-03-01

    Full Text Available Cultivation of Pleurotus spp. reached to the second largest in amount after Agaricus bisporus (Lange sing. in the world. There recently has also been growing interest to cultivate them on wastes of forest and agricultural plants in Turkey. In the scope of study Pleurotus florida was produced on beech wood sawmill waste and rice brain. Beech wood sawmill waste (Fagus orientalis Lipsky were used as main substrate and supplemented with rice brain as co-substrate by 10 % W/W, 0 % W/W, 40 % W/W mixing ratios based on dry weights. To produce P. florida substrates were ground, air dried, moistured up to 70-80 % by tap water, supplemented, pasteurized with live steam and spawned. Highest yields (440 gr/kg of P. florida were obtained by supplementing wood waste and rice brain (% 80 + % 20. Furthermore, the best mycelia development were obtained by % 90 + % 10.

  11. 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.

  12. Thermophilic co-digestion of organic fraction of municipal solid wastes with FOG wastes from a sewage treatment plant: reactor performance and microbial community monitoring.

    Science.gov (United States)

    Martín-González, Lucia; Castro, Rita; Pereira, M Alcina; Alves, M Madalena; Font, Xavier; Vicent, Teresa

    2011-04-01

    Working at thermophilic conditions instead of mesophilic, and also the addition of a co-substrate, are both the ways to intend to improve the anaerobic digestion of the source-collected organic fraction of municipal solid wastes (SC-OFMSW). Addition of sewage treatment plant fat, oil and grease wastes (STP-FOGW), that are nowadays sent to landfill, would represent an opportunity to recover a wasted methane potential and, moreover, improve the whole process. In this study, after a first period feeding only SC-OFMSW, a co-digestion step was performed maintaining thermophilic conditions. During the co-digestion period enhancements in biogas production (52%) and methane yield (36%) were achieved. In addition, monitoring of microbial structure by using PCR-DGGE and cloning techniques showed that bacterial community profiles clustered in two distinct groups, before and after the extended contact with STP-FOGW, being more affected by the STP-FOGW addition than the archaeal one.

  13. Dissolution of particulate phosphorus in pig slurry through biological acidification: A critical step for maximum phosphorus recovery as struvite.

    Science.gov (United States)

    Piveteau, Simon; Picard, Sylvie; Dabert, Patrick; Daumer, Marie-Line

    2017-08-08

    Recycling phosphorus as struvite from pig slurry requires an acidification step to dissolve the inorganic solids containing most of the phosphorus. This study focused on the biological acidification of several pig slurries using sucrose as a model organic co-substrate. Lactic acid fermentation occurred systematically, dissolving 60-90% of TP (total phosphorus) and T-Mg (total magnesium) at pH 6 or lower. Optimal pH range for maximum P dissolution aimed at struvite recovery was 5.5-6. A simple model was developed correlating pH, sucrose and buffer capacity to optimize P dissolution and future recovery using real organic waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain

    Science.gov (United States)

    Chan, Mun Chiang; Atasoylu, Onur; Hodson, Emma; Tumber, Anthony; Leung, Ivanhoe K. H.; Chowdhury, Rasheduzzaman; Gómez-Pérez, Verónica; Demetriades, Marina; Rydzik, Anna M.; Holt-Martyn, James; Tian, Ya-Min; Bishop, Tammie; Claridge, Timothy D. W.; Kawamura, Akane; Pugh, Christopher W.; Ratcliffe, Peter J.; Schofield, Christopher J.

    2015-01-01

    As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs). Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs). Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4) induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke. PMID:26147748

  15. Potent and Selective Triazole-Based Inhibitors of the Hypoxia-Inducible Factor Prolyl-Hydroxylases with Activity in the Murine Brain.

    Directory of Open Access Journals (Sweden)

    Mun Chiang Chan

    Full Text Available As part of the cellular adaptation to limiting oxygen availability in animals, the expression of a large set of genes is activated by the upregulation of the hypoxia-inducible transcription factors (HIFs. Therapeutic activation of the natural human hypoxic response can be achieved by the inhibition of the hypoxia sensors for the HIF system, i.e. the HIF prolyl-hydroxylases (PHDs. Here, we report studies on tricyclic triazole-containing compounds as potent and selective PHD inhibitors which compete with the 2-oxoglutarate co-substrate. One compound (IOX4 induces HIFα in cells and in wildtype mice with marked induction in the brain tissue, revealing that it is useful for studies aimed at validating the upregulation of HIF for treatment of cerebral diseases including stroke.

  16. Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) by Aeromonas hydrophila and Recombinant Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    丘远征; 刘力平; 陈国强

    2003-01-01

    Aeromonas hydrophila (A.hydrophila) 4AK4 produced poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) (PHBHHx) with an almost constant 3-hydroxyhexanoate (3HHx) content of 10%-15% from lauric acid and/or soybean oil.Both A.hydrophila 4AK4 and recombinant Escherichia coli (E.coli) JMU193 (pBH32) produced PHBHHx with controllable 3HHx content when fed lauric acid and another co-substrate.With glucose or gluconate as the co-substrate, the 3HHx content in the copolyester produced by A.hydrophila 4AK4 was reduced slightly from 12% to 9%.However, the 3HHx content in the copolyester produced by E.coli JMU193 (pBH32) was significantly reduced from 9% to 2% with fructose as the co-substrate.These results show that regulation of 3HHx content in PHBHHx can be achieved using genetically engineered E.coli.

  17. Optimization of anaerobic digestion of a mixture of Zea mays and Miscanthus sacchariflorus silages with various pig manure dosages.

    Science.gov (United States)

    Bułkowska, K; Pokój, T; Klimiuk, E; Gusiatin, Z M

    2012-12-01

    Digestion of crop silage (Zea mays L. and Miscanthus sacchariflorus) with 0%, 7.5%, 12.5% and 25% pig manure as co-substrate was performed in continuous stirred-tank reactors, for a constant hydraulic retention time of 45 d and organic load rate of 2.1 g L(-1)d(-1). A matrix of correlations between biogas/methane production and parameters of anaerobic digestion was created in order to estimate process stability. The values of the correlation coefficients indicated that the most stable anaerobic digestion was achieved using 7.5% and 12.5% pig manure. In contrast, the positive correlation between ammonium and volatile fatty acids (r=0.8698, psilage alone, pig manure favored the production of biogas and methane; the highest production rates were obtained with 12.5% pig manure.

  18. Biogas production from ensiled meadow grass; effect of mechanical pretreatments and rapid determination of substrate biodegradability via physicochemical methods.

    Science.gov (United States)

    Tsapekos, P; Kougias, P G; Angelidaki, I

    2015-04-01

    As the biogas sector is rapidly expanding, there is an increasing need in finding new alternative feedstock to biogas plants. Meadow grass can be a suitable co-substrate and if ensiled it can be supplied to biogas plants continuously throughout the year. Nevertheless, this substrate is quite recalcitrant and therefore efficient pretreatment is needed to permit easy access of microbes to the degradable components. In this study, different mechanical pretreatment methods were applied on ensiled meadow grass to investigate their effect on biomass biodegradability. All the tested pretreatments increased the methane productivity and the increase ranged from 8% to 25%. The best mechanical pretreatment was the usage of two coarse mesh grating plates. Additionally, simple analytical methods were conducted to investigate the possibility of rapidly determining the methane yield of meadow grass. Among the methods, electrical conductivity test showed the most promising calibration statistics (R(2)=0.68).

  19. Environmental Consequences of Future Biogas Technologies based on Separated Slurry

    DEFF Research Database (Denmark)

    Hamelin, Lorie; Wesnæs, Marianne; Wenzel, Henrik

    2011-01-01

    the volatile solids in the solid fraction. The biogas scenario involving the most efficient separation technology resulted in a dry matter separation efficiency of 87% and allowed a net reduction of the global warming potential of 40%, compared to the reference slurry management. This figure comprises......This consequential life cycle assessment study highlights the key environmental aspects of producing biogas from separated pig and cow slurry, a relatively new but probable scenario for future biogas production, as it avoids the reliance on constrained carbon cosubstrates. Three scenarios involving...... different slurry separation technologies have been assessed and compared to a business-as-usual reference slurry management scenario. The results show that the environmental benefits of such biogas production are highly dependent upon the efficiency of the separation technology used to concentrate...

  20. Methane production and energy evaluation of a farm scaled biogas plant in cold climate area.

    Science.gov (United States)

    Fjørtoft, Kristian; Morken, John; Hanssen, Jon Fredrik; Briseid, Tormod

    2014-10-01

    The aim of this study was to investigate the specific methane production and the energy balance at a small farm scaled mesophilic biogas plant in a cold climate area. The main substrate was dairy cow slurry. Fish silage was used as co-substrate for two of the three test periods. Energy production, substrate volumes and thermal and electric energy consumption was monitored. Methane production depended mainly on type and amount of substrates, while energy consumption depended mainly on the ambient temperature. During summer the main thermal energy consumption was caused by heating of new substrates, while covering for thermal energy losses from digester and pipes required most thermal energy during winter. Fish silage gave a total energy production of 1623 k Wh/m(3), while the dairy cow slurry produced 79 k Wh/m(3) slurry. Total energy demand at the plant varied between 26.9% and 88.2% of the energy produced.

  1. THE BIOTRANSFORMATION, BIODEGRADATION, AND BIOREMEDIATION OF ORGANIC COMPOUNDS BY MICROALGAE(1).

    Science.gov (United States)

    Ghasemi, Younes; Rasoul-Amini, Sara; Fotooh-Abadi, Elham

    2011-10-01

    Rapid growth in the biotechnological industry and production has put tremendous pressure on the biological methods that may be used according to the guidelines of green chemistry. However, despite continuing dramatic increases in published research on organic biotransformation by microorganisms, more research exists with microalgae. Our efforts in transforming chemicals such as organic compounds for the production of functionalized products help to lessen the environmental effects of organic synthesis. These biotransformations convert organic contaminants to obtain carbon or energy for growth or as cosubstrates. This review aims to focus on the potential of microalgae in transformation, conversion, remediation, accumulation, degradation, and synthesis of various organic compounds. However, these technologies have the ability to provide the most efficient and environmentally safe approach for inexpensive biotransforming of a variety of organic contaminants, which are most industrial residues. In addition, the recent advances in microalgal bioactivity were discussed. © 2011 Phycological Society of America.

  2. Choline-based ionic liquids-enhanced biodegradation of azo dyes.

    Science.gov (United States)

    Sekar, Sudharshan; Surianarayanan, Mahadevan; Ranganathan, Vijayaraghavan; MacFarlane, Douglas R; Mandal, Asit Baran

    2012-05-01

    Industrial wastewaters such as tannery and textile processing effluents are often characterized by a high content of dissolved organic dyes, resulting in large values of chemical and biological oxygen demand (COD and BOD) in the aquatic systems into which they are discharged. Such wastewater streams are of rapidly growing concern as a major environmental issue in developing countries. Hence there is a need to mitigate this challenge by effective approaches to degrade dye-contaminated wastewater. In this study, several choline-based salts originally developed for use as biocompatible hydrated ionic liquids (i.e., choline sacchrinate (CS), choline dihydrogen phosphate (CDP), choline lactate (CL), and choline tartarate (CT)) have been successfully employed as the cosubstrate with S. lentus in the biodegradation of an azo dye in aqueous solution. We also demonstrate that the azo dye has been degraded to less toxic components coupled with low biomass formation.

  3. BIOGAS PRODUCTION FROM CATCH CROPS

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Larsen, Søren U.; Ahring, Birgitte Kiær

    2014-01-01

    Catch crop cultivation combined with its use for biogas production would increase renewable energy production in the form of methane, without interfering with the production of food and fodder crops. The low biomass yield of catch crops is the main limiting factor for using these crops as co......-substrate in manure-based biogas plants and the profit obtained from the sale of biogas barely compensates for the harvest costs. A new agricultural strategy to harvest catch crops together with the residual straw of the main crop was investigated to increase the biomass and thereby the methane yield per hectare...... biomass. Leaving the straw on the field until harvest of the catch crop in the autumn could benefit biogas production due to the organic matter degradation of the straw taking place on the field during the autumn months. This new agricultural strategy may be a good alternative to achieve economically...

  4. Valorization of crude glycerol from biodiesel production

    Directory of Open Access Journals (Sweden)

    Konstantinović Sandra S.

    2016-01-01

    Full Text Available The increased production of biodiesel as an alternative fuel involves the simultaneous growth in production of crude glycerol as its main by-product. Therefore, the feasibility and sustainability of biodiesel production requires the effective utilization of crude glycerol. This review describes various uses of crude glycerol as a potential green solvent for chemical reactions, a starting raw material for chemical and biochemical conversions into value-added chemicals, a substrate or co-substrate in microbial fermentations for synthesis of valuable chemicals and production of biogas and biohydrogen as well as a feedstuff for animal feed. A special attention is paid to various uses of crude glycerol in biodiesel production. [Projekat Ministarstva nauke Republike Srbije, br. III 45001

  5. Environmental sustainability assessment of fruit cultivation and processing using fruit and cocoa residues for bioenergy and compost. Case study from Ghana

    DEFF Research Database (Denmark)

    Kamp, Andreas; Østergård, Hanne

    2016-01-01

    cultivation,transport and processing. The option ‘Present practice’ presents data from a case study where production is characterised by soil loss and synthetic fertiliser dependence in cultivation and grid supply of electricity in processing. The option ‘Biogas’ is hypothetical and characterised by biogas...... and electricity production using farming and processing residues and by recycling of nutrients and carbon to soil. Cocoa shells are used as a co-substrate in the biogas production. Estimating the environmental impact of cocoa shell residues exposes the multifunctionality issue, continuously debated in ESA...... the system expansion method, we find that, in comparison with ‘Present practice’, the option ‘Biogas’ eliminates netsoil carbon loss and reduces synthetic fertiliser, diesel and external electricity requirements at the expense of a relatively small increase in human labour input. The ESA includes...

  6. The crystal structure of the complex of Zea mays alpha subunit with a fragment of human beta subunit provides the clue to the architecture of protein kinase CK2 holoenzyme

    DEFF Research Database (Denmark)

    Battistutta, R; Sarno, S; De Moliner, E

    2000-01-01

    The crystal structure of a complex between the catalytic alpha subunit of Zea mays CK2 and a 23-mer peptide corresponding the C-terminal sequence 181-203 of the human CK2 regulatory beta subunit has been determined at 3.16-A resolution. The complex, composed of two alpha chains and two peptides......, presents a molecular twofold axis, with each peptide interacting with both alpha chains. In the derived model of the holoenzyme, the regulatory subunits are positioned on the opposite side with respect to the opening of the catalytic sites, that remain accessible to substrates and cosubstrates. The beta...... subunit can influence the catalytic activity both directly and by promoting the formation of the alpha2 dimer, in which each alpha chain interacts with the active site of the other. Furthermore, the two active sites are so close in space that they can simultaneously bind and phosphorylate two...

  7. Enhanced biodegradation of total polycyclic aromatic hydrocarbons (TPAHs) by marine halotolerant Achromobacter xylosoxidans using Triton X-100 and β-cyclodextrin--a microcosm approach.

    Science.gov (United States)

    Dave, Bharti P; Ghevariya, Chirag M; Bhatt, Jwalant K; Dudhagara, Dushyant R; Rajpara, Rahul K

    2014-02-15

    Ability of Achromobacter xylosoxidans, a chrysene degrading marine halotolerant bacterium to degrade polycyclic aromatic hydrocarbons (PAHs) using a cost effective laboratory microcosm approach, was investigated. Effect of variables as chrysene, glucose as a co-substrate, Triton X-100 as a non-ionic surfactant and β-cyclodextrin as a PAHs solubilizer was examined on degradation of low molecular weight (LMW) and high molecular weight (HMW) PAHs. A total of eleven PAHs detected from polluted saline soil were found to be degraded. Glucose, in combination with Triton X-100 and β-cyclodextrin resulted in 2.8 and 1.4-fold increase in degradation of LMW PAHs and 7.59 and 2.23-fold increase in degradation of HMW PAHs, respectively. Enhanced biodegradation of total PAHs (TPAHs) by amendments with Triton X-100 and β-cyclodextrin using Achromobacter xylosoxidans can prove to be promising approach for in situ bioremediation of marine sites contaminated with PAHs.

  8. Laccases to take on the challenge of emerging organic contaminants in wastewater.

    Science.gov (United States)

    Gasser, Christoph A; Ammann, Erik M; Shahgaldian, Patrick; Corvini, Philippe F-X

    2014-12-01

    The removal of emerging organic contaminants from municipal wastewater poses a major challenge unsatisfactorily addressed by present wastewater treatment processes. Enzyme-catalyzed transformation of emerging organic contaminants (EOC) has been proposed as a possible solution to this major environmental issue more than a decade ago. Especially, laccases gained interest in this context in recent years due to their broad substrate range and since they only need molecular oxygen as a cosubstrate. In order to ensure the stability of the enzymes and allow their retention and reuse, either immobilization or insolubilization of the biocatalysts seems to be the prerequisite for continuous wastewater treatment applications. The present review summarizes the research conducted on EOC transformation with laccases and presents an overview of the possible immobilization techniques. The goal is to assess the state of the art and identify the next necessary steps that have to be undertaken in order to implement laccases as a tertiary wastewater treatment process in sewage treatment plants.

  9. [Progress in electricity generation from biomass using microbial fuel cell MFC)].

    Science.gov (United States)

    Feng, Yu-Jie; Wang, Xin; Li, He; Yang, Qiao; Qu, You-Peng; Shi, Xin-Xin; Liu, Jia; He, Wei-Hua; Xie, Ming-Li

    2010-10-01

    By applying bacteria as anodic catalyst, microbial fuel cell (MFC) can directly convert biomass energy into electrical energy, provided a new way for biomass utilization. Previous studies showed that the substrates and their concentration substantially affected performance of MFC. High power output was obtained when simple organic such as volatile fatty acids (VFA), alcohols or glucose was used as substrate. However, physical, chemical or even biological pretreatment methods were needed when substrate was complex organic. Addition of simple organic as co-substrate was also demonstrated to be an efficient way for refractory compounds degradation in MFC. Using biomass as substrates, MFC will be applied in area such as bioenergy recovery from wastewater, power supply in outfield and biosensors.

  10. Multi-criteria analyses of wastewater treatment bio-processes under an uncertainty and a multiplicity of steady states.

    Science.gov (United States)

    Južnič-Zonta, Zivko; Kocijan, Juš; Flotats, Xavier; Vrečko, Darko

    2012-11-15

    This paper presents a multi-criteria evaluation methodology for determining the operating strategies for bio-chemical, wastewater treatment plants based on a model analysis under an uncertainty that can present multiple steady states. The method is based on Monte Carlo (MC) simulations and the expected utility theory in order to deal with the analysis of choices among risky operating strategies with multi-dimensional outcomes. The motivation is given by a case study using an anaerobic digestion model (ADM) adapted for multiple co-substrates. It is shown how the multi-criteria analyses' computational complexity can be reduced within an approximation based on Gaussian-process regression and how a reliability map can be built for a bio-process model under uncertainty and multiplicity. In our uncertainty-analyses case study, the reliability map shows the probability of a biogas-production collapse for a given set of substrates mixture input loads.

  11. Effect of Different Carbon Source on Expression of Carotenogenic Genes and Astaxanthin Production in Xanthophyllomyces dendrorhous

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-10-01

    Full Text Available The present research gives an insight into astaxanthin production, as well as transcription differences of four key carotenogenic genes, in Xanthophyllomyces dendrorhous when cultured with various carbon sources and soybean oil as co-substrates. Glucose was found to be the carbon source with best culture growth and astaxanthin production and the addition of 2% (v/v soybean oil resulted in even higher astaxanthin producing. In addition, four carotenogenic genes encoding geranylgeranyl diphosphate synthase (crtE, phytoene desaturase (crtl, phytoene synthase lycopene cyclase(crtYB, and astaxanthin synthetase (ast, respectively, were demonstrated to be associated with different transcription levels under various substrates. The present study suggests the effectiveness of manipulating the metabolic regulation by using different carbon sources, in order to improve the production of astaxanthin.

  12. Sirtuins are Unaffected by PARP Inhibitors Containing Planar Nicotinamide Bioisosteres.

    Science.gov (United States)

    Ekblad, Torun; Schüler, Herwig

    2016-03-01

    PARP-family ADP-ribosyltransferases (PARPs) and sirtuin deacetylases all use NAD(+) as cosubstrate for ADP-ribosyl transfer. PARP inhibitors are important research tools and several are being evaluated in cancer treatment. With the exception of a few tankyrase inhibitors, all current PARP inhibitors mimic the nicotinamide moiety in NAD(+) and block the nicotinamide binding pocket. We report here that while the activities of the four human sirtuin isoforms SIRT1, SIRT2, SIRT3 and SIRT6 are blocked by sirtuin inhibitor Ex527 in vitro, they are unaffected by the seven clinical and commonly used PARP inhibitors niraparib, olaparib, rucaparib, talazoparib, veliparib, PJ34, and XAV939. These findings indicate that PARP inhibitors containing planar nicotinamide mimetics do not bind to sirtuin cofactor sites. In conclusion, a simple commercially available assay can be used to rule out interference of novel PARP inhibitors with sirtuin NAD(+) binding. © 2015 John Wiley & Sons A/S.

  13. Anaerobic digestion of pig manure and glycerol from biodiesel production

    Directory of Open Access Journals (Sweden)

    Pakamas Chetpattananondh, Sumate Chaiprapat, Chaisri Suksaroj

    2015-01-01

    Full Text Available Increasing biodiesel production causes a surplus of glycerol. This work aims to investigate the crude glycerol pretreatment method and then apply the glycerol as a co-substrate with pig manure for anaerobic digestion. The optimum crude glycerol pretreatment method was acidification with 6% of H2SO4 that highest glycerol recovery was obtained with lowest cost. Co-digestions of glycerol and pig manure enhanced biogas and methane productions compared with mono-digestions. Biogas and methane productions in semi-continuous digestions were highly effected by OLR. The optimum OLR was 3.06 kg SCOD/m3 that biogas production was maintained at 3 L/d with methane composition of 72% and SCOD removal higher than 80%.

  14. Biomethanization of sugar beet byproduct by semi-continuous single digestion and co-digestion with cow manure.

    Science.gov (United States)

    Aboudi, Kaoutar; Álvarez-Gallego, Carlos José; Romero-García, Luis Isidoro

    2016-01-01

    Dried pellet of exhausted sugar beet cossettes were digested alone and combined with cow manure as co-substrate in a mesophilic semi-continuous anaerobic system. In single digestion assay, the stable biogas production and stable reactor operation was observed at the hydraulic retention time (HRT) of 20days (OLR: 3.26gVS/Lreactord) which was the minimum HRT tolerated by the system. However, co-digestion with cow manure allowed to decrease the HRT until 15days (OLR: 4.97gVS/Lreactord) with 32% higher biogas generation and efficient reactor operation. Propionic acid was the predominant VFA observed during single digestion assay failure, while acetic acid accumulation was observed in the co-digestion assay. In both single and co-digestion assays, the recovery of digesters was possible by ceasing the feeding and re-inoculation with a well-adapted inoculum.

  15. Structure and function of dioxygenases in histone demethylation and DNA/RNA demethylation

    Directory of Open Access Journals (Sweden)

    Cheng Dong

    2014-11-01

    Full Text Available Iron(II and 2-oxoglutarate (2OG-dependent dioxygenases involved in histone and DNA/RNA demethylation convert the cosubstrate 2OG and oxygen to succinate and carbon dioxide, resulting in hydroxylation of the methyl group of the substrates and subsequent demethylation. Recent evidence has shown that these 2OG dioxygenases play vital roles in a variety of biological processes, including transcriptional regulation and gene expression. In this review, the structure and function of these dioxygenases in histone and nucleic acid demethylation will be discussed. Given the important roles of these 2OG dioxygenases, detailed analysis and comparison of the 2OG dioxygenases will guide the design of target-specific small-molecule chemical probes and inhibitors.

  16. Diazinon degradation by a novel strain Ralstonia sp. DI-3 and X-ray crystal structure determination of the metabolite of diazinon

    Indian Academy of Sciences (India)

    GUANGLI WANG; YUAN LIU

    2016-09-01

    Diazinon is a widely used organophosphorus insecticide often detected in the environment. A highly effectivediazinon-degrading Ralstonia sp. strain DI-3 was isolated from agricultural soil. Strain DI-3 can utilize dimethoateas its sole carbon source for growth and degrade an initial concentration of 100 mg·L^{−1} diazinon to non-detectablelevels within 60 h in liquid culture. A small amount of second carbon source as co-substrate could slightly enhance thebiodegradation of diazinon. In addition, a less toxic metabolic intermediate formed during the degradation of diazinonmediated by strain DI-3 was purified using thin-layer chromatography (TLC) and identified based on single-crystal Xraydiffraction analysis, allowing a degradation pathway for diazinon by pure culture to be proposed. Finally, this isthe first providing authentic evidence to describe the metabolite.

  17. Food Waste to Energy: An Overview of Sustainable Approaches for Food Waste Management and Nutrient Recycling.

    Science.gov (United States)

    Paritosh, Kunwar; Kushwaha, Sandeep K; Yadav, Monika; Pareek, Nidhi; Chawade, Aakash; Vivekanand, Vivekanand

    2017-01-01

    Food wastage and its accumulation are becoming a critical problem around the globe due to continuous increase of the world population. The exponential growth in food waste is imposing serious threats to our society like environmental pollution, health risk, and scarcity of dumping land. There is an urgent need to take appropriate measures to reduce food waste burden by adopting standard management practices. Currently, various kinds of approaches are investigated in waste food processing and management for societal benefits and applications. Anaerobic digestion approach has appeared as one of the most ecofriendly and promising solutions for food wastes management, energy, and nutrient production, which can contribute to world's ever-increasing energy requirements. Here, we have briefly described and explored the different aspects of anaerobic biodegrading approaches for food waste, effects of cosubstrates, effect of environmental factors, contribution of microbial population, and available computational resources for food waste management researches.

  18. Enzyme Characterization in Microreactors by UV-Vis Spectroscopy

    DEFF Research Database (Denmark)

    Ringborg, Rolf Hoffmeyer; Krühne, Ulrich; Woodley, John

    for selection can at this point be improved by characterization of the enzyme performance where also inhibition and toxicity effects are taken into account. Enzyme characterization is here defined as the effect on initial rate of reaction with respect to pH, enzyme, substrate, co-substrate, product and co......-product concentration [2]. From this investigation, it will be possible to determine whether the enzyme meets the criteria for process requirements or not. The development of the process will determine the requirements and this can also reach a state of maturity that resolves obstacles, lowers criteria and paves......, as the enzyme resource is scarce at this point of development. In the case where the reaction operates with UV active components, UV can be used to detect compounds with high sensitivity supplemented by multivariate data analysis. The spectra are here decorrelated and regressed to yield concentrations...

  19. Food Waste to Energy: An Overview of Sustainable Approaches for Food Waste Management and Nutrient Recycling

    Directory of Open Access Journals (Sweden)

    Kunwar Paritosh

    2017-01-01

    Full Text Available Food wastage and its accumulation are becoming a critical problem around the globe due to continuous increase of the world population. The exponential growth in food waste is imposing serious threats to our society like environmental pollution, health risk, and scarcity of dumping land. There is an urgent need to take appropriate measures to reduce food waste burden by adopting standard management practices. Currently, various kinds of approaches are investigated in waste food processing and management for societal benefits and applications. Anaerobic digestion approach has appeared as one of the most ecofriendly and promising solutions for food wastes management, energy, and nutrient production, which can contribute to world’s ever-increasing energy requirements. Here, we have briefly described and explored the different aspects of anaerobic biodegrading approaches for food waste, effects of cosubstrates, effect of environmental factors, contribution of microbial population, and available computational resources for food waste management researches.

  20. Food Waste to Energy: An Overview of Sustainable Approaches for Food Waste Management and Nutrient Recycling

    Science.gov (United States)

    Paritosh, Kunwar; Kushwaha, Sandeep K.; Yadav, Monika; Pareek, Nidhi; Chawade, Aakash

    2017-01-01

    Food wastage and its accumulation are becoming a critical problem around the globe due to continuous increase of the world population. The exponential growth in food waste is imposing serious threats to our society like environmental pollution, health risk, and scarcity of dumping land. There is an urgent need to take appropriate measures to reduce food waste burden by adopting standard management practices. Currently, various kinds of approaches are investigated in waste food processing and management for societal benefits and applications. Anaerobic digestion approach has appeared as one of the most ecofriendly and promising solutions for food wastes management, energy, and nutrient production, which can contribute to world's ever-increasing energy requirements. Here, we have briefly described and explored the different aspects of anaerobic biodegrading approaches for food waste, effects of cosubstrates, effect of environmental factors, contribution of microbial population, and available computational resources for food waste management researches.

  1. Ammonia - LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process

    DEFF Research Database (Denmark)

    Wang, Han; Fotidis, Ioannis; Angelidaki, Irini

    2016-01-01

    uninhibited production, respectively. At the same time control reactor (RCTL), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an “ammonia–LCFA (long chain fatty acids) synergetic......In the current study it has been hypothesized that, when organic loading of an anaerobic reactor is increased, the additional cell biomass biosynthesis would capture more ammonia nitrogen and thereby reduce the ammonia toxicity. Therefore, the alleviation of the toxicity of high ammonia levels...... using lipids (glycerol trioleate-GTO) or carbohydrates (glucose-GLU) as co-substrates in manure-based thermophilic continuous stirred-tank reactors (RGTO and RGLU, respectively) was tested. At 5 g NH4+-N L−1, relative methane production of RGTO and RGLU, was 10.5% and 41% compared to the expected...

  2. Succinic semialdehyde as a substrate for the formation of gamma-aminobutyric acid.

    Science.gov (United States)

    van Bemmelen, F J; Schouten, M J; Fekkes, D; Bruinvels, J

    1985-11-01

    The conversion of succinic semialdehyde into gamma-aminobutyric acid (GABA) by GABA-transaminase was measured in rat brain homogenate in the presence of different concentrations of the cosubstrate glutamate. The calculated kinetic parameters of succinic semialdehyde for GABA-transaminase were a limiting Km value of 168 microM and a limiting Vmax value of 38 mumol g-1 h-1. Combination with previously obtained data for the conversion of GABA into succinic semialdehyde revealed a kEq value of 0.04, indicating that equilibrium of GABA-transaminase is biased toward the formation of GABA. The increased formation of GABA in the presence of succinic semialdehyde was not due to an increased conversion of glutamate into GABA by glutamic acid decarboxylase. Therefore these results indicate that succinic semialdehyde can act as a precursor for GABA synthesis.

  3. A microbial biomanufacturing platform for natural and semisynthetic opioids.

    Science.gov (United States)

    Thodey, Kate; Galanie, Stephanie; Smolke, Christina D

    2014-10-01

    Opiates and related molecules are medically essential, but their production via field cultivation of opium poppy Papaver somniferum leads to supply inefficiencies and insecurity. As an alternative production strategy, we developed baker's yeast Saccharomyces cerevisiae as a microbial host for the transformation of opiates. Yeast strains engineered to express heterologous genes from P. somniferum and bacterium Pseudomonas putida M10 convert thebaine to codeine, morphine, hydromorphone, hydrocodone and oxycodone. We discovered a new biosynthetic branch to neopine and neomorphine, which diverted pathway flux from morphine and other target products. We optimized strain titer and specificity by titrating gene copy number, enhancing cosubstrate supply, applying a spatial engineering strategy and performing high-density fermentation, which resulted in total opioid titers up to 131 mg/l. This work is an important step toward total biosynthesis of valuable benzylisoquinoline alkaloid drug molecules and demonstrates the potential for developing a sustainable and secure yeast biomanufacturing platform for opioids.

  4. Evaluation of carbon degradation during co-composting of exhausted grape marc with different biowastes.

    Science.gov (United States)

    Fernández, F J; Sánchez-Arias, V; Villaseñor, J; Rodríguez, L

    2008-10-01

    In this work the carbon biodegradation of exhausted grape marc (EGM) combined with other organic wastes using the turned pile composting system was studied. Four different piles were made of EGM in Pile 1, EGM mixed with cow manure and straw (CMS) in Pile 2, EGM mixed with municipal solid waste (MSW) in Pile 3 and EGM mixed with grape stalks (GS) in Pile 4. The results obtained were modelled to determine the main kinetic and stoichiometric parameters. Regarding to the rate constants of the composting processes they were increased from 0.033d(-1), the value obtained when EGM was composted alone, to 0.040 and 0.044d(-1) when MSW and GS were added, respectively as co-substrates. However, the addition of CMS reduced the rate constant. About the biodegradable carbon fractions, it was observed that the co-composting reduced significantly the remanent carbon concentration after composting in all the piles whilst increased the readily biodegradable carbon fractions from 35, the value obtained when EGM was composted alone, to 50 and 60%, respectively when MSW or GS were added. As regards the temperature profiles, only Piles 1 and 4 achieved thermal hygienization values and about the nitrogen losses, the lowest percentage of nitrogen loss took place when GS were added, because of its optimum pH and C/N initial ratio. Thus, though any of these wastes could be used for co-composting with EGM, the use of GS as co-substrate and bulking agent for the co-composting process of EGM was recommended.

  5. Bacteria obtained from a sequencing batch reactor that are capable of growth on dehydroabietic acid.

    Science.gov (United States)

    Mohn, W W

    1995-06-01

    Eleven isolates capable of growth on the resin acid dehydroabietic acid (DhA) were obtained from a sequencing batch reactor designed to treat a high-strength process stream from a paper mill. The isolates belonged to two groups, represented by strains DhA-33 and DhA-35, which were characterized. In the bioreactor, bacteria like DhA-35 were more abundant than those like DhA-33. The population in the bioreactor of organisms capable of growth on DhA was estimated to be 1.1 x 10(6) propagules per ml, based on a most-probable-number determination. Analysis of small-subunit rRNA partial sequences indicated that DhA-33 was most closely related to Sphingomonas yanoikuyae (Sab = 0.875) and that DhA-35 was most closely related to Zoogloea ramigera (Sab = 0.849). Both isolates additionally grew on other abietanes, i.e., abietic and palustric acids, but not on the pimaranes, pimaric and isopimaric acids. For DhA-33 and DhA-35 with DhA as the sole organic substrate, doubling times were 2.7 and 2.2 h, respectively, and growth yields were 0.30 and 0.25 g of protein per g of DhA, respectively. Glucose as a cosubstrate stimulated growth of DhA-33 on DhA and stimulated DhA degradation by the culture. Pyruvate as a cosubstrate did not stimulate growth of DhA-35 on DhA and reduced the specific rate of DhA degradation of the culture. DhA induced DhA and abietic acid degradation activities in both strains, and these activities were heat labile. Cell suspensions of both strains consumed DhA at a rate of 6 mumol mg of protein-1 h-1.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Potential uses of Elodea nuttallii-harvested biomass

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Escobar, Marcela; Fuehner, Christoph; Zehnsdorf, Andreas [Centre for Environmental Biotechnology (UBZ), Leipzig (Germany); Voyevoda, Maryna [UFZ-Helmholtz Centre for Environmental Research, Leipzig (Germany). Analytical Chemistry Dept.

    2011-12-15

    Elodea nuttallii (PLANCH) St. John, an aquatic plant native to North America, shows invasive traits outside of its area of origin. In Europe, the plant has spread rapidly in water bodies. In Germany, the massive occurrence of E. nuttallii restricts recreational activities on lakes. Massive occurrences of E. nuttallii have been managed up to now by harvesting the plant and disposing of the biomass as organic waste, which results in high maintenance costs for lake administrators. Alternative uses to the disposal of the biomass were investigated. Analyzing the components and elemental composition of E. nuttallii samples from nine lakes in Germany, several potential uses were identified, such as the use of E. nuttallii biomass as a co-substrate with maize silage for biogas generation. Other potential applications, such as biochart production, soil amelioration, and energy recovery of feedstock chars in combustion plants, were identified from a hydrothermal carbonization process. The presence of {beta}-sitosterol in E. nuttallii, which is used in the treatment of enlarged prostates, indicates a pharmaceutical use. Even though the elemental composition of E. nuttallii biomass contains the elements of a complete fertilizer, this particular use is not recommended given its slow decomposition in soil. The most feasible alternative identified was the use of E. nuttallii biomass as a co-substrate for biogas generation in combination with maize silage. The mixing of E. nuttallii with maize silage to facilitate storage and short distances between biogas plants and lakes with massive occurrence of E. nuttallii are important factors for its applicability. (orig.)

  7. Investigation of decolorization of textile wastewater in an anaerobic/aerobic biological activated carbon system (A/A BAC).

    Science.gov (United States)

    Pasukphun, N; Vinitnantharat, S; Gheewala, S

    2010-04-01

    The aim of this study is to investigate the decolorization in anaerobic/aerobic biological activated carbon (A/A BAC) system. The experiment was divided into 2 stages; stage I is batch test for preliminary study of dye removal equilibrium time. The preliminary experiment (stage I) provided the optimal data for experimental design of A/A BAC system in SBR (stage II). Stage II is A/A BAC system imitated Sequencing Batch Reactor (SBR) which consist of 5 main periods; fill, react, settle, draw and idle. React period include anaerobic phase followed by aerobic phase. The BAC main media; Granular Activated Carbon (GAC), Mixed Cultures (MC) and Biological Activated Carbon (BAC) were used for dye and organic substances removal in three different solutions; Desizing Agent Solution (DAS), dye Solution (DS) and Synthetic Textile Wastewater (STW). Results indicate that GAC adsorption plays role in dye removal followed by BAC and MC activities, respectively. In the presence desizing agent, decolorization by MC was improved because desizing agent acts as co-substrates for microorganisms. It was found that 50% of dye removal efficiency was achieved in Fill period by MC. GC/MS analysis was used to identify dye intermediate from decolorization. Dye intermediate containing amine group was found in the solution and on BAC surfaces. The results demonstrated that combination of MC and BAC in the system promotes decolorization and dye intermediate removal. In order to improve dye removal efficiency in an A/A BAC system, replacement of virgin GAC, sufficient co-substrates supply and the appropriate anaerobic: aerobic period should be considered.

  8. Assessing anaerobic co-digestion of pig manure with agroindustrial wastes: the link between environmental impacts and operational parameters.

    Science.gov (United States)

    Rodriguez-Verde, Ivan; Regueiro, Leticia; Carballa, Marta; Hospido, Almudena; Lema, Juan M

    2014-11-01

    Anaerobic co-digestion (AcoD) is established as a techno-economic profitable process by incrementing biogas yield (increased cost-efficiency) and improving the nutrient balance (better quality digestate) in comparison to mono-digestion of livestock wastes. However, few data are available on the environmental consequences of AcoD and most of them are mainly related to the use of energy crops as co-substrates. This work analysed the environmental impact of the AcoD of pig manure (PM) with several agroindustrial wastes (molasses, fish, biodiesel and vinasses residues) using life cycle assessment (LCA) methodology. For comparative purposes, mono digestion of PM has also been evaluated. Four out of six selected categories (acidification, eutrophication, global warming and photochemical oxidation potentials) showed environmental impacts in all the scenarios assessed, whereas the other two (abiotic depletion and ozone layer depletion potentials) showed environmental credits, remarking the benefit of replacing fossil fuels by biogas. This was also confirmed by the sensitivity analysis applied to the PM quality (i.e. organic matter content) and the avoided energy source demonstrating the importance of the energy recovery step. The influence of the type of co-substrate could not be discerned; however, a link between the environmental performance and the hydraulic retention time, the organic loading rate and the nutrient content in the digestate could be established. Therefore, LCA results were successfully correlated to process variables involved in AcoD, going a step further in the combination of techno-economic and environmental feasibilities. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Phosphorus recycling potential assessment by a biological test applied to wastewater sludge.

    Science.gov (United States)

    Braak, Etienne; Auby, Sarah; Piveteau, Simon; Guilayn, Felipe; Daumer, Marie-Line

    2016-01-01

    Phosphorus (P) recycling as mineral fertilizer from wastewater activated sludge (WAS) depends on the amount that can be dissolved and separated from the organic matter before the final crystallization step. The aim of the biological phosphorus dissolution potential (BPDP) test developed here was to assess the maximum amount of P that could be biologically released from WAS prior that the liquid phase enters the recovery process. It was first developed for sludge combining enhanced biological phosphorus removal and iron chloride. Because carbohydrates are known to induce acidification during the first stage of anaerobic digestion, sucrose was used as a co-substrate. Best results were obtained after 24-48 h, without inoculum, with a sugar/sludge ratio of 0.5 gCOD/gVS and under strict anaerobic conditions. Up to 75% of the total phosphorus in sludge from a wastewater treatment plant combining enhanced biological phosphorus removal and iron chloride phosphorus removal could be dissolved. Finally, the test was applied to assess BPDP from different sludge using alum compounds for P removal. No dissolution was observed when alum polychloride was used and less than 20% when alum sulphate was used. In all the cases, comparison to chemical acidification showed that the biological process was a major contributor to P dissolution. The possibility to crystallize struvite was discussed from the composition of the liquids obtained. The BPDP will be used not only to assess the potential for phosphorus recycling from sludge, but also to study the influence of the co-substrates available for anaerobic digestion of sludge.

  10. A review of dark fermentative hydrogen production from biodegradable municipal waste fractions

    Energy Technology Data Exchange (ETDEWEB)

    De Gioannis, G., E-mail: degioan@unica.it [DICAAR – Department of Civil and Environmental Engineering and Architecture, University of Cagliari, Cagliari (Italy); IGAG-CNR, Environmental Geology and Geoengineering Institute of the National Research Council (Italy); Muntoni, A. [DICAAR – Department of Civil and Environmental Engineering and Architecture, University of Cagliari, Cagliari (Italy); IGAG-CNR, Environmental Geology and Geoengineering Institute of the National Research Council (Italy); Polettini, A.; Pomi, R. [Department of Hydraulics, Transportation and Roads, University of Rome “La Sapienza” (Italy)

    2013-06-15

    Highlights: ► A large number of factors affect fermentative hydrogen production. ► Harmonization and systematic comparison of results from different literature sources are needed. ► More than 80 publications on H{sub 2} production from food waste and OFMSW have been examined. ► Experimental data from the reviewed literature were analyzed using statistical tools. ► For a reliable assessment of the process performance, the use of multiple parameters appears to be recommended. - Abstract: Hydrogen is believed to play a potentially key role in the implementation of sustainable energy production, particularly when it is produced from renewable sources and low energy-demanding processes. In the present paper an attempt was made at critically reviewing more than 80 recent publications, in order to harmonize and compare the available results from different studies on hydrogen production from FW and OFMSW through dark fermentation, and derive reliable information about process yield and stability in view of building related predictive models. The review was focused on the effect of factors, recognized as potentially affecting process evolution (including type of substrate and co-substrate and relative ratio, type of inoculum, food/microorganisms [F/M] ratio, applied pre-treatment, reactor configuration, temperature and pH), on the fermentation yield and kinetics. Statistical analysis of literature data from batch experiments was also conducted, showing that the variables affecting the H{sub 2} production yield were ranked in the order: type of co-substrate, type of pre-treatment, operating pH, control of initial pH and fermentation temperature. However, due to the dispersion of data observed in some instances, the ambiguity about the presence of additional hidden variables cannot be resolved. The results from the analysis thus suggest that, for reliable predictive models of fermentative hydrogen production to be derived, a high level of consistency between data is

  11. Interaction of periodate-oxidized UDP-glucuronic acid with recombinant human liver UDP-glucuronosyltransferase 1A6.

    Science.gov (United States)

    Battaglia, E; Terrier, N; Mizeracka, M; Senay, C; Magdalou, J; Fournel-Gigleux, S; Radominska-Pandya, A

    1998-08-01

    Sodium periodate reacts with UDP-glucuronic acid (UDP-GlcUA) to generate a reactive derivative [periodate-oxidized UDP-GlcUA (o-UDP-GlcUA)]. The ability of this analog of UDP-GlcUA to inactivate and label the human recombinant UDP-glucuronosyltransferase (UGT) UGT1A6 via the UDP-GlcUA binding site was investigated. At an o-UDP-GlcUA concentration of 20 mM, the enzymatic activity of UGT1A6 was totally inactivated after 30 min of incubation at pH 7.4. Inhibition was irreversible, time-dependent, and concentration-dependent and exhibited pseudo-first order kinetics (kinact = 4.0 M-1.min-1). Cosubstrate protection with UDP-GlcUA was biphasic, with no protection in the first phase and almost total protection in the second phase, suggesting that at least 65% of the cross-linking occurs at the cosubstrate binding site. Partial inactivation by o-UDP-GlcUA led to a decrease in Vmax, suggesting that o-UDP-GlcUA can act as an active site-directed inhibitor. Furthermore, proteins, including the UGTs, from membrane fractions of a recombinant V79 cell line expressing the UGT1A6 enzyme and from rat liver microsomes were cross-linked by in situ periodate oxidation of [beta-32P]UDP-GlcUA. The present results suggest that periodate-oxidized UDP-GlcUA, which inactivates UGT1A6 by the possible formation of a Schiff base adduct with active site lysyl residues, can be used as a new affinity label for the UDP-GlcUA binding site.

  12. High acetone-butanol-ethanol production in pH-stat co-feeding of acetate and glucose.

    Science.gov (United States)

    Gao, Ming; Tashiro, Yukihiro; Wang, Qunhui; Sakai, Kenji; Sonomoto, Kenji

    2016-08-01

    We previously reported the metabolic analysis of butanol and acetone production from exogenous acetate by (13)C tracer experiments (Gao et al., RSC Adv., 5, 8486-8495, 2015). To clarify the influence of acetate on acetone-butanol-ethanol (ABE) production, we first performed an enzyme assay in Clostridium saccharoperbutylacetonicum N1-4. Acetate addition was found to drastically increase the activities of key enzymes involved in the acetate uptake (phosphate acetyltransferase and CoA transferase), acetone formation (acetoacetate decarboxylase), and butanol formation (butanol dehydrogenase) pathways. Subsequently, supplementation of acetate during acidogenesis and early solventogenesis resulted in a significant increase in ABE production. To establish an efficient ABE production system using acetate as a co-substrate, several shot strategies were investigated in batch culture. Batch cultures with two substrate shots without pH control produced 14.20 g/L butanol and 23.27 g/L ABE with a maximum specific butanol production rate of 0.26 g/(g h). Furthermore, pH-controlled (at pH 5.5) batch cultures with two substrate shots resulted in not only improved acetate consumption but also a further increase in ABE production. Finally, we obtained 15.13 g/L butanol and 24.37 g/L ABE at the high specific butanol production rate of 0.34 g/(g h) using pH-stat co-feeding method. Thus, in this study, we established a high ABE production system using glucose and acetate as co-substrates in a pH-stat co-feeding system with C. saccharoperbutylacetonicum N1-4.

  13. The First Aspartic Acid of the DQxD Motif for Human UDP-Glucuronosyltransferase 1A10 Interacts with UDP-Glucuronic Acid during Catalysis

    Science.gov (United States)

    Xiong, Yan; Patana, Anne-Sisko; Miley, Michael J.; Zielinska, Agnieszka K.; Bratton, Stacie M.; Miller, Grover P.; Goldman, Adrian; Finel, Moshe; Redinbo, Matt R.; Radominska-Pandya, Anna

    2008-01-01

    All UDP-glucuronosyltransferase enzymes (UGTs) share a common cofactor, UDP-glucuronic acid (UDP-GlcUA). The binding site for UDP-GlcUA is localized to the C-terminal domain of UGTs on the basis of amino acid sequence homology analysis and crystal structures of glycosyltransferases, including the C-terminal domain of human UGT2B7. We hypothesized that the 393DQMD-NAK399 region of human UGT1A10 interacts with the glucuronic acid moiety of UDP-GlcUA. Using site-directed mutagenesis and enzymatic analysis, we demonstrated that the D393A mutation abolished the glucuronidation activity of UGT1A10 toward all substrates. The effects of the alanine mutation at Q394, D396, and K399 on glucuronidation activities were substrate-dependent. Previously, we examined the importance of these residues in UGT2B7. Although D393 (D398 in UGT2B7) is similarly critical for UDP-GlcUA binding in both enzymes, the effects of Q394 (Q399 in UGT2B7) to Ala mutation on activity were significant but different between UGT1A10 and UGT2B7. A model of the UDP-GlcUA binding site suggests that the contribution of other residues to cosubstrate binding may explain these differences between UGT1A10 and UGT2B7. We thus postulate that D393 is critical for the binding of glucuronic acid and that proximal residues, e.g., Q394 (Q399 in UGT2B7), play a subtle role in cosubstrate binding in UGT1A10 and UGT2B7. Hence, this study provides important new information needed for the identification and understanding of the binding sites of UGTs, a major step forward in elucidating their molecular mechanism. PMID:18048489

  14. Structural and mechanistic studies on carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily catalyzing the first step in carbapenem biosynthesis.

    Science.gov (United States)

    Sleeman, Mark C; Sorensen, John L; Batchelar, Edward T; McDonough, Michael A; Schofield, Christopher J

    2005-10-14

    The first step in the biosynthesis of the medicinally important carbapenem family of beta-lactam antibiotics is catalyzed by carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily. CarB catalyzes formation of (2S,5S)-carboxymethylproline [(2S,5S)-t-CMP] from malonyl-CoA and l-glutamate semialdehyde. In addition to using a cosubstrate, CarB catalyzes C-C and C-N bond formation processes as well as an acyl-coenzyme A hydrolysis reaction. We describe the crystal structure of CarB in the presence and absence of acetyl-CoA at 2.24 A and 3.15 A resolution, respectively. The structures reveal that CarB contains a conserved oxy-anion hole probably required for decarboxylation of malonyl-CoA and stabilization of the resultant enolate. Comparison of the structures reveals that conformational changes (involving His(229)) in the cavity predicted to bind l-glutamate semialdehyde occur on (co)substrate binding. Mechanisms for the formation of the carboxymethylproline ring are discussed in the light of the structures and the accompanying studies using isotopically labeled substrates; cyclization via 1,4-addition is consistent with the observed labeling results (providing that hydrogen exchange at the C-6 position of carboxymethylproline does not occur). The side chain of Glu(131) appears to be positioned to be involved in hydrolysis of the carboxymethylproline-CoA ester intermediate. Labeling experiments ruled out the possibility that hydrolysis proceeds via an anhydride in which water attacks a carbonyl derived from Glu(131), as proposed for 3-hydroxyisobutyryl-CoA hydrolase. The structural work will aid in mutagenesis studies directed at altering the selectivity of CarB to provide intermediates for the production of clinically useful carbapenems.

  15. The mechanism of oxidative halophenol dehalogenation by Amphitrite ornata dehaloperoxidase is initiated by H2O2 binding and involves two consecutive one-electron steps: role of ferryl intermediates.

    Science.gov (United States)

    Osborne, Robert L; Coggins, Michael K; Raner, Gregory M; Walla, Mike; Dawson, John H

    2009-05-26

    The enzymatic globin, dehaloperoxidase (DHP), from the terebellid polychaete Amphitrite ornata is designed to catalyze the oxidative dehalogenation of halophenol substrates. In this study, the ability of DHP to catalyze this reaction by a mechanism involving two consecutive one-electron steps via the normal order of addition of the oxidant cosubstrate (H(2)O(2)) before organic substrate [2,4,6-trichlorophenol (TCP)] is demonstrated. Specifically, 1 equiv of H(2)O(2) will fully convert 1 equiv of TCP to 2,6-dichloro-1,4-benzoquinone, implicating the role of multiple ferryl [Fe(IV)O] species. A significant amount of heterolytic cleavage of the O-O bond of cumene hydroperoxide, consistent with transient formation of a Compound I [Fe(IV)O/porphyrin pi-cation radical] species, is observed upon its reaction with ferric DHP. In addition, a more stable high-valent Fe(IV)O-containing DHP intermediate [Compound II (Cpd II) or Compound ES] is characterized by UV-visible absorption and magnetic circular dichroism spectroscopy. Spectral similarities are seen between this intermediate and horse heart myoglobin Cpd II. It is also shown in single-turnover experiments that the DHP Fe(IV)O intermediate is an active oxidant in halophenol oxidative dehalogenation. Furthermore, reaction of DHP with 4-chlorophenol leads to a dimeric product. The results presented herein are consistent with a normal peroxidase order of addition of the oxidant cosubstrate (H(2)O(2)) followed by organic substrate (TCP) and indicate that the enzymatic mechanism of DHP-catalyzed oxidative halophenol dehalogenation involves two consecutive one-electron steps with a dissociable radical intermediate.

  16. Synergistic effect of co-digestion to enhance anaerobic degradation of catering waste and orange peel for biogas production.

    Science.gov (United States)

    Anjum, Muzammil; Khalid, Azeem; Qadeer, Samia; Miandad, Rashid

    2017-09-01

    Catering waste and orange peel were co-digested using an anaerobic digestion process. Orange peel is difficult to degrade anaerobically due to the presence of antimicrobial agents such as limonene. The present study aimed to examine the feasibility of anaerobic co-digestion of catering waste with orange peel to provide the optimum nutrient balance with reduced inhibitory effects of orange peel. Batch experiments were conducted using catering waste as a potential substrate mixed in varying ratios (20-50%) with orange peel. Similar ratios were followed using green vegetable waste as co-substrate. The results showed that the highest organic matter degradation (49%) was achieved with co-digestion of catering waste and orange peel at a 50% mixing ratio (CF4). Similarly, the soluble chemical oxygen demand (sCOD) was increased by 51% and reached its maximum value (9040 mg l(-1)) due to conversion of organic matter from insoluble to soluble form. Biogas production was increased by 1.5 times in CF4 where accumulative biogas was 89.61 m(3) t(-1)substrate compared with 57.35 m(3) t(-1)substrate in the control after 80 days. The main reason behind the improved biogas production and degradation is the dilution of inhibitory factors (limonene), with subsequent provision of balanced nutrients in the co-digestion system. The tCOD of the final digestate was decreased by 79.9% in CF4, which was quite high as compared with 68.3% for the control. Overall, this study revealed that orange peel waste is a highly feasible co-substrate for anaerobic digestion with catering waste for enhanced biogas production.

  17. Flavin redox chemistry precedes substrate chlorination during the reaction of the flavin-dependent halogenase RebH.

    Science.gov (United States)

    Yeh, Ellen; Cole, Lindsay J; Barr, Eric W; Bollinger, J Martin; Ballou, David P; Walsh, Christopher T

    2006-06-27

    The flavin-dependent halogenase RebH catalyzes chlorination at the C7 position of tryptophan as the initial step in the biosynthesis of the chemotherapeutic agent rebeccamycin. The reaction requires reduced FADH(2) (provided by a partner flavin reductase), chloride ion, and oxygen as cosubstrates. Given the similarity of its sequence to those of flavoprotein monooxygenases and their common cosubstrate requirements, the reaction of FADH(2) and O(2) in the halogenase active site was presumed to form the typical FAD(C4a)-OOH intermediate observed in monooxygenase reactions. By using stopped-flow spectroscopy, formation of a FAD(C4a)-OOH intermediate was detected during the RebH reaction. This intermediate decayed to yield a FAD(C4a)-OH intermediate. The order of addition of FADH(2) and O(2) was critical for accumulation of the FAD(C4a)-OOH intermediate and for subsequent product formation, indicating that conformational dynamics may be important for protection of labile intermediates formed during the reaction. Formation of flavin intermediates did not require tryptophan, nor were their rates of formation affected by the presence of tryptophan, suggesting that tryptophan likely does not react directly with any flavin intermediates. Furthermore, although final oxidation to FAD occurred with a rate constant of 0.12 s(-)(1), quenched-flow kinetic data showed that the rate constant for 7-chlorotryptophan formation was 0.05 s(-)(1) at 25 degrees C. The kinetic analysis establishes that substrate chlorination occurs after completion of flavin redox reactions. These findings are consistent with a mechanism whereby hypochlorite is generated in the RebH active site from the reaction of FADH(2), chloride ion, and O(2).

  18. Balance of groundwaterstreams below dumps with the application of environmental isotopes within hydrogeological examinations. Final report; Bilanzierung von Grundwasserstroemen unter Deponien mit Hilfe von umweltisotopen-hydrologischen Analysen im Rahmen hydrogeologischer Untersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Geyh, M.A.; Ays, G.

    1995-08-15

    Deponiesickerwaesser eine von der natuerlichen Isotopenzusammensetzung abweichende Markierung haben koennten, die vom Deponieinhalt und Isotopen-Fraktionierungen bei dessen Abbau gepraegt ist. Die Isotopenwerte des Grundwassers ober- oder unterstrom der Deponien wurden zu verschiedenen Jahreszeiten gemessen, um natuerliche und anthropogene Veraenderungen der Isotopenzusammensetzungen im Deponiebereich zu erfassen. Es wurde erwartet, dass die Mobilitaet der chemischen Kontaminanten durch physikalische, chemische und biologische Retardation gegenueber der der isotopisch markierten Wassermolekuele eingeschraenkt sei. Im Abstrom von Hausmuelldeponien koennen mit Hilfe der Sauerstoff- und Kohlenstoff-Isotopenzusammensetzung im Sickerwasser unterschiedlich stark von der Deponie beeinflusste Bereiche voneinander abgegrenzt werden. Die Kohlenstoff-Isotopenzusammensetzung kann zur Verfolgung der Phasen des chemischen Abbaus organischer Inhaltsstoffe eingesetzt werden. In Sonderabfalldeponien treten spezielle Isotopen-Effekte auf, die mit der andersartigen Zusammensetzung der Inhaltsstoffe zu erklaeren sind. (orig.)

  19. Decontamination of PAH polluted soils by fungi. Subproject: PAH degradation balance and testing of the extended laboratory process. Final report; Dekontamination von PAK belasteten Boeden durch Pilze. Teilprojekt: Bilanzierung des PAK-Abbaus und Erprobung des erweiterten Laborverfahrens. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Martens, R.; Zadrazil, F.; Wolter, M.; Bahadir, M.

    1997-09-01

    The aim of the research project was first to select a fungus with a high potential for mineralization of polycyclic aromatic hydrocarbons (PAH) and a good ability to colonize different soils. The application of this fungus for a degradation of PAH in soil had to be tested. In a screening of 57 white rot fungi the fungus Pleurotus sp. Florida fulfilled these requirements best. In pure culture it was able to metabolize and mineralize highly condensed 4-6 ring PAH to a great extent. For instance, up to 50% of {sup 14}C-pyrene or 39% of {sup 14}C-benzo(a)pyrene was mineralized to {sup 14}CO{sub 2} within 15 weeks. If different carriers for {sup 14}C-pyrene were used the mineralization correlated with the bioavailability, which was characterized by the desorption of the compound from the carriers with water. The mineralization of {sup 14}C-pyrene, {sup 14}C-benz(a)anthracene; {sup 14}C-benzo(a)-pyrene and {sup 14}C-dibenz(a, h)anthracene in native soils showed that a colonization with Pl. sp Florida inhibited the degradation of the less recalcitrant {sup 14}C-pyrene by the indigenous soil microflora. However, the mineralization of the carcinogenic, very recalcitrant and high condensed {sup 14}C-PAH was considerably supported by the fungus. Therefore this capabilities of the fungus could not be proven in a joint medium-scale soil experiment (0.8 m{sup 3} soil) which had been conducted within a parmership with scientists in Jena and an industriell firm. Because of safety aspects only the low condensed less recalcitrant PAH could be applied in this experiment. (orig./MG) [Deutsch] Ziel der Untersuchungen war es, zunaechst aus einer groesseren Zahl von Weissfaeulepilzen Pilze zu selektieren, die ein hohes Abbaupotential fuer PAK besitzen. Fuer die effektive Bildung der fuer den Xenobiotika-Abbau wahrscheinlich verantwortlichen lignolytischen Enzyme sollten die Pilze auf Stroh mit einer Kontamination von {sup 14}C-Pyren angezogen werden. An Hand der Freisetzung von {sup 14

  20. “Green” or “Red”? Reframing the Environmental Discourse in Nigeria „Grün“ oder „Rot“? Zur Themenverschiebung im nigerianischen umweltpolitischen Diskurs

    Directory of Open Access Journals (Sweden)

    Akin Iwilade

    2012-01-01

    zentrale Thema eines sozialen Diskurses zum Abbau von Ressourcen ist die Eigentumsfrage und nicht notwendigerweise die Nachhaltigkeit; wird der Diskurs von sozialen Bewegungen bestimmt, wird die einzigartige umweltpolitische Relevanz möglicherweise nicht ausreichend herausgestellt. Der Autor plädiert für eine alternative Themensetzung im umweltpolitischen Diskurs in Entwicklungsländern wie Nigeria.

  1. Evaluation and development of soil values for the pathway 'soil to plant'. Transfer factors soil to plant; Ueberpruefung und Fortentwicklung der Bodenwerte fuer den Boden-Pflanze-Pfad. Teilbericht 1: Transferfaktoren Boden-Pflanze

    Energy Technology Data Exchange (ETDEWEB)

    Trapp, S.; Matthies, M.; Reiter, B.; Gaeth, S.

    2001-10-01

    . Aufnahme aus der Bodenloesung und Translokation mit den Pflanzensaeften spielt - ausser fuer Phenanthren - kaum eine Rolle. Bei den untersuchten Moehren und Kartoffeln ist vorwiegend die Schale kontaminiert. Die Transferfaktoren der PCB sind durchweg hoeher als die der PAK. Es wird vermutet, dass dafuer der photolytische Abbau von PAK auf Blattoberflaechen verantwortlich ist. Des Weiteren gibt es Hinweise darauf, dass die Metabolisierung von PAK in Pflanzen schneller ablaeuft als die der PCB. (orig.)

  2. Laser diagnosis and plasma technology: Fundamentals for reduction of emissions and fuel consumption in DI internal combustion engines. Sub-project: Purification of diesel exhaust in pulsed plasma. Final report; Laserdiagnostische und plasmatechnologische Grundlagen zur Verminderung von Emissionen und Kraftstoffverbrauch von DI-Verbrennungsmotoren. Teilvorhaben: Reinigung von Dieselabgasen in gepulsten Plasmen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, T.; Kishimoto, T.; Birckigt, R.

    2000-12-01

    gezeigt werden, dass es sich um einen synergetischen Effekt handelt, bei dem die katalytische Reduktion durch plasmainduzierte Oxidation eines Teils des NO's ausgeloest wird. Basierend auf dieser Kenntnis des Reaktionsmechanismus wurden geeignet dimensionierte Pulsplasma- und SCR-Reaktoren aufgebaut und in Pruefstandsmessungen an einem modernen Pkw-Motor gestestet. Unter kaltstart- und stadtverkehrsaehnlichen Bedingungen konnten mit Plasmaleistungen unter 300 W rund 60% des NOx reduziert werden, maximale Reduktionsgrade von bis zu 85% wurden erreicht. Der plasmainduzierte Abbau von Kohlenwasserstoffen und Partikeln, die Bildung von Nebenprodukten und der Einfluss von Kohlenwasserstoffen und Partikeln auf den plasmainduzierten SCR-Prozess wurden untersucht. Prozesse, die gegen einen Einsatz des Plasma-SCR-Verfahrens sprechen, wurden nicht gefunden. (orig.)

  3. Estudios ecológicos en el Páramo de Cruz Verde, Colombia. IV. La actividad biológica del suelo en diferentes asociaciones vegetales Estudios ecológicos en el Páramo de Cruz Verde, Colombia. IV. La actividad biológica del suelo en diferentes asociaciones vegetales

    Directory of Open Access Journals (Sweden)

    Schnetter Marie-Luise

    1976-09-01

    - Gesellschaft überhaupt kein Abbau feststellbar war.

  4. Zero-emission wood chip drier with terpene recovery. Project 2: Condensate treatment and terpene production. Final report; Emissonsfreier Holzspaenetrockner mit Rueckgewinnung von Terpenen. Teilvorhaben 2: Kondensataufbereitung und Terpengewinnung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bormann, H.; Sievers, M.

    2002-07-01

    Ausbeuten fuer Kiefernholzoel in Hoehe von 0,5 bis 1,7 Liter Oel je m{sup 3} Kondensat in Abhaengigkeit von der Kondensationstemperatur ermittelt. Die Holzoele enthalten 40 bis 70% Terpenverbindungen (Mono-, Sesqui-, Diterpene sowie Terpineole) und liegen in einer parfuemistisch und flavoristisch interessanten Zusammensetzung vor. Weitere Untersuchungen zur Kondensataufbereitung zeigten, dass sowohl eine Pervaporation als auch eine Vakuumdestillation eine gute Abtrennung weiterer geloester Terpenverbindungen ermoeglichen. Untersuchungen zur biologischen Behandlung bestaetigen einen guten und weitestgehenden Abbau der Kondensatinhaltsstoffe bis auf Direkteinleiterqualitaet. Die Wirtschaftlichkeitsbetrachtung auf Basis der Pilotversuche ergab, dass eine integrierte Terpengewinnung insbesondere im Zusammenhang mit einer Nutzung der Kondensate als Prozesswasser sowie einer teilweisen Nutzung der freiwerdenden Kondensationswaerme oekonomisch interessant sein kann. (orig.)

  5. Suspension membrane reactor for biological elimination of non-degradable materials from mixed effluents. Final report; Suspensionsmembranreaktor zur biologischen Eliminierung schwer abbaubarer Stoffe aus Abwassergemischen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Raebiger, N.; Schierenbeck, A.

    2002-07-01

    zurueckgefuehrt, um einen vollstaendigen Abbau durch die Einstellung einer substratspezifischen Verweilzeit zu gewaehrleisten. Durch eine zwischengeschaltete Mikrofiltration wird die Biomasse zurueckgehalten und somit das Aufwachsen eines Biofilms im Nanofiltrationsteil verhindert. Die Anwendung des bestehenden Suspensions-Membranreaktors und der neuen zweistufigen Anlagen erfolgt im zweiten Teil des Forschungsvorhabens anhand eines synthetischen Abwassers mit dem praxisrelevanten Modellschadstoff 4-Chlorphenol sowie anhand eines realen industriellen Prozessabwassers der Filzfrei-Behandlung aus der Bremer Wollkaemmerei mit einem erhoehten AOX-Gehalt. (orig.)

  6. Coordinated field measurements to determine the effects of leewaves on the formation of polar stratospheric clouds. Final report; Koordinierte Feldmessungen zum Einfluss von Leewellen auf Wolkenfelder in der polaren Stratosphaere. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, K.H.

    2000-09-21

    Heterogenous reactions on polar stratospheric clouds (PSC) initiate a long chain of chemical reactions which lead to catalytic destruction of ozone. In the relatively warm Arctic winter stratosphere PSCs are mainly generated in leewave dominated areas. The active remote sensing instrumentation at Alomar and the Esrange on either side of the Scandinavian mountain ridge was used to study the formation of leewave-PSCs in coordinated field measurements. This project supported the University of Bonn backscatter lidar operations in these leewave campaigns. The Bonn Lidar was setup at the Esrange and operated during several campaigns from 1997 to 1999. PSCs were detected in the first two winters, while there were no PSCs in the third winter because of a major stratospheric warming. In the first winter we counted almost three times more PSCs than expected from the large scale temperature fields. Modifying the synoptic temperatures by leewave cooling estimated from a parameterization of internal waves leads to a much better agreement of observations with predictions. We deduce that leewaves double the instants of PSC formation in the downwind area of the Scandinavian mountains. The number of cases with highly reactive PSC II (mother-of-pearl clouds) increases by more than an order of magnitude. Leewaves are directly visible in the lidar derived temperature profiles above the aerosol layer. (orig.) [German] Heterogene Reaktionen an Wolken in der polaren Stratosphaere (PSC) setzen einen langkettigen Chemismus in Gang, der zum katalytischen Abbau von Ozon fuehrt. In der relativ warmen arktischen Winterstratosphaere entstehen PSCs bevorzugt in Leewellengebieten. Mit aktiver Fernerkundung von den Stationen Alomar und Esrange beiderseits des skandinavischen Bergrueckens wurde in koordinierten Feldmessungen die Bildung von Leewellen-PSCs untersucht. Mit diesem Vorhaben wurde das Rueckstreulidar der Universitaet Bonn auf der Esrange gefoerdert. Das Lidar wurde dort aufgebaut und

  7. Depth profiles of the inorganic chemical composition of soil water in the unsaturated zone; Tiefenprofile der anorganisch-chemischen Zusammensetzung von Bodenwasser in der ungesaettigten Zone

    Energy Technology Data Exchange (ETDEWEB)

    Hoess, J.

    1992-04-01

    gemeinsamen Forschungsvorhaben des Projekts `Wasser-Abfall-Boden` des Landes Baden-Wuerttemberg. Es wurden verschiedene Flaechen beprobt, insbesondere zwei Aecker, wovon der eine `konventionell`, der andere `umweltschonend`, d.h. mit geringerem Einsatz von Agrarchemikalien und reduzierter Bodenbearbeitung bewirtschaftet wurde. Die Nitrat-Konzentration betrug im Mittel der drei untersuchten Bewirtschaftungsjahre unter der umweltschonend bewirtschafteten Flaeche nur 30% der unter der konventionell bewirtschafteten. Dies bedeutet, dass der Nitrateintrag in das darunter anstehende Grundwasser durch die Art der gewaehlten Bewirtschaftung um das gleiche Mass reduziert werden konnte. Die Untersuchungen zum Salzgehalt des Bodenwassers ergaben, dass er bereits in der obersten Bodenzone (0 - 25 cm) sehr hoch ist und mit zunehmender Bodentiefe nicht mehr steigt. Daraus kann geschlossen werden, dass er durch Vorgaenge in der Wurzelzone und durch die dort vorhandene hohe mikrobiologische Aktivitaet bestimmt wird. Die Sickerung durch die darunterliegenden Schichten bewirkt im wesentlichen nur eine Verschiebung im Kationen- bzw. Anionenverhaeltnis. (orig.).

  8. Boosting biogas production from sewage sludge by adding small amount of agro-industrial by-products and food waste residues.

    Science.gov (United States)

    Maragkaki, A E; Fountoulakis, M; Kyriakou, A; Lasaridi, K; Manios, T

    2017-04-17

    In Greece, in many cities, wastewater treatment plants (WWTPs) operate their own anaerobic digestion (AD) facility in order to treat sewage sludge rather than achieve optimum biogas production. Nowadays, there is a growing interest regarding the addition of other co-substrates in these existing facilities in order to increase gas yield from the biomass. This practice may be possible by adding small amount of co-substrates which will not affect significantly in the designed hydraulic retention time. Nonetheless, the lack of experimental data regarding this option is a serious obstacle. In this study, the effect of co-digestion sewage sludge, with small amount of agro-industrial by-products and food wastes is examined in lab-scale experiments. Specifically, co-digestion of SS and food waste (FW), grape residues (GR), crude glycerol (CG), cheese whey (CW) and sheep manure (SM), in a small ratio of 5-10% (v/v) was investigated. The effect of agro-industrial by-products and food waste residues on biogas production was investigated using one 1L and three 3L lab-scale reactors under mesophilic conditions at a 24-day hydraulic retention time. The biogas production rate reached 223, 259, 406, 572, 682 and 1751 mlbiogas/lreactor/d for 100% SS, 5% SM & 95% SS, 10% CW & 90% SS, 5% FW & 95% SS, 5% FW & 5% CG & 90% SS and 5% CG & 95% SS respectively. Depending on the co-digestion material, the average removal of total chemical oxygen demand (TCOD) ranged between 20% (5% SM & 95% SS) and 76% (5% FW & 5% CG & 90% SS). Reduction in the volatile solids ranged between 26% (5% SM & 95% SS) and 62% (5% FW & 5% CG & 90% SS) for organic loading rates between 0.8kgVSm(-3)d(-1) and 2.0kgVSm(-3)d(-1). Moreover, co-digestion improved biogas production from 14% (5% SM & 95% SS) to 674% (5% CG & 95% SS). This work suggests that WWTPs in Greece can increase biogas production by adding other wastes to the sewage sludge without affecting the operation of existing digesters and without requiring

  9. Identification of PAHX, a Refsum disease gene.

    Science.gov (United States)

    Mihalik, S J; Morrell, J C; Kim, D; Sacksteder, K A; Watkins, P A; Gould, S J

    1997-10-01

    Refsum disease is an autosomal recessive disorder characterized by retinitis pigmentosa, peripheral polyneuropathy, cerebellar ataxia and increased cerebrospinal fluid protein. Biochemically, the disorder is defined by two related properties: pronounced accumulation of phytanic acid and selective loss of the peroxisomal dioxygenase required for alpha-hydroxylation of phytanoyl-CoA2. Decreased phytanic-acid oxidation is also observed in human cells lacking PEX7, the receptor for the type-2 peroxisomal targetting signal (PTS2; refs 3,4), suggesting that the enzyme defective in Refsum disease is targetted to peroxisomes by a PTS2. We initially identified the human PAHX and mouse Pahx genes as expressed sequence tags (ESTs) capable of encoding PTS2 proteins. Human PAHX is targetted to peroxisomes, requires the PTS2 receptor for peroxisomal localization, interacts with the PTS2 receptor in the yeast two-hybrid assay and has intrinsic phytanoyl-CoA alpha-hydroxylase activity that requires the dioxygenase cofactor iron and cosubstrate 2-oxoglutarate. Radiation hybrid data place PAHX on chromosome 10 between the markers D10S249 and D10S466, a region previously implicated in Refsum disease by homozygosity mapping. We find that both Refsum disease patients examined are homozygous for inactivating mutations in PAHX, demonstrating that mutations in PAHX can cause Refsum disease.

  10. Process optimization of biogas energy production from cow dung with alkali pre-treated coffee pulp.

    Science.gov (United States)

    Selvankumar, T; Sudhakar, C; Govindaraju, M; Selvam, K; Aroulmoji, V; Sivakumar, N; Govarthanan, M

    2017-08-01

    Biogas production from cow dung with co-substrate agricultural waste is one of the most demanding technologies for generating energy in a sustainable approach considering eco-friendly. In the present study, coffee pulp (CP) was pre-treated with 1% NaOH and combined with various proportions of cow dung (CD) to explore its biogas producing potentiality. The optimization of the process was studied using Response surface methodology. Statistics based on 3-D plots were generated to evaluate the changes in the response surface and to understand the relationship between the biogas yield and other parameters. The highest methane production (144 mL/kg) was achieved after 90 h of incubation with 1:3 of CP and CD at 40 °C. Gas chromatography analyzes the chemical compositions of the generated biogas and its post combustion emissions. The chemical composition of the substrates before digestion and after fermentation (biogas spent sludge) were measured in terms of fiber content and the values were noted as, total solids (0.53%), ash content (9.2%), volatile fatty acid (100 mg/L), organic carbon (46%) and a total carbohydrate (179 mg/g). The results of the optimization of biogas production presented in this work found to have significance with the process parameters. The outcome of the study has supported the fact of conventional combustion technology that has to be upgraded to prevent these hazardous emissions into the atmosphere.

  11. Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw.

    Science.gov (United States)

    Nair, Ramkumar B; Kabir, Maryam M; Lennartsson, Patrik R; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

    2017-06-08

    Integration of wheat straw for a biorefinery-based energy generation process by producing ethanol and biogas together with the production of high-protein fungal biomass (suitable for feed application) was the main focus of the present study. An edible ascomycete fungal strain Neurospora intermedia was used for the ethanol fermentation and subsequent biomass production from dilute phosphoric acid (0.7 to 1.2% w/v) pretreated wheat straw. At optimum pretreatment conditions, an ethanol yield of 84 to 90% of the theoretical maximum, based on glucan content of substrate straw, was observed from fungal fermentation post the enzymatic hydrolysis process. The biogas production from the pretreated straw slurry showed an improved methane yield potential up to 162% increase, as compared to that of the untreated straw. Additional biogas production, using the syrup, a waste stream obtained post the ethanol fermentation, resulted in a combined total energy output of 15.8 MJ/kg wheat straw. Moreover, using thin stillage (a waste stream from the first-generation wheat-based ethanol process) as a co-substrate to the biogas process resulted in an additional increase by about 14 to 27% in the total energy output as compared to using only wheat straw-based substrates. ᅟ.

  12. Purification and characterization of an NADPH-cytochrome P450 (cytochrome c) reductase from spearmint (Mentha spicata) glandular trichomes.

    Science.gov (United States)

    Ponnamperuma, K; Croteau, R

    1996-05-01

    Solubilized NADPH-cytochrome c (P450) reductase was purified to homogeneity from an extract of spearmint (Mentha spicata) glandular trichomes by dye-ligand interaction chromatography on Matrex-Gel Red A and affinity chromatography on 2', 5'-adenosine diphosphate agarose. SDS-PAGE of the purified enzyme preparation revealed the presence of two similar proteins with masses of 82 kDa (major) and 77 kDa (minor) that crossreacted on immunoblot analysis with polyclonal antibodies directed against NADPH-cytochrome P450 reductase from Jerusalem artichoke and from mung bean. Complete immunoinhibition of reductase activity was observed with both types of polyclonal antibodies, while only partial inhibition of activity resulted using a family of monoclonal antibodies directed against the Jerusalem artichoke cytochrome P450 reductase. Inhibition of the spearmint oil gland cytochrome c reductase was also observed with the diphenyliodonium ion. The K(m) values for the cosubstrates NADPH and cytochrome c were 6.2 and 3.7 microM, respectively, and the pH optimum for activity was at 8.5. The NADPH-cytochrome c reductase reconstituted NADPH-dependent (-)-4S-limonene-6-hydroxylase activity in the presence of cytochrome P450, purified from the microsomal fraction of spearmint oil gland cells and dilauroyl phosphatidyl choline. These characteristics establish the identity of the purified enzyme as a NADPH-cytochrome P450 reductase.

  13. Propofol Inhibits SIRT2 Deacetylase through a Conformation-specific, Allosteric Site*

    Science.gov (United States)

    Weiser, Brian P.; Eckenhoff, Roderic G.

    2015-01-01

    meta-Azi-propofol (AziPm) is a photoactive analog of the general anesthetic propofol. We photolabeled a myelin-enriched fraction from rat brain with [3H]AziPm and identified the sirtuin deacetylase SIRT2 as a target of the anesthetic. AziPm photolabeled three SIRT2 residues (Tyr139, Phe190, and Met206) that are located in a single allosteric protein site, and propofol inhibited [3H]AziPm photolabeling of this site in myelin SIRT2. Structural modeling and in vitro experiments with recombinant human SIRT2 determined that propofol and [3H]AziPm only bind specifically and competitively to the enzyme when co-equilibrated with other substrates, which suggests that the anesthetic site is either created or stabilized in enzymatic conformations that are induced by substrate binding. In contrast to SIRT2, specific binding of [3H]AziPm or propofol to recombinant human SIRT1 was not observed. Residues that line the propofol binding site on SIRT2 contact the sirtuin co-substrate NAD+ during enzymatic catalysis, and assays that measured SIRT2 deacetylation of acetylated α-tubulin revealed that propofol inhibits enzymatic function. We conclude that propofol inhibits the mammalian deacetylase SIRT2 through a conformation-specific, allosteric protein site that is unique from the previously described binding sites of other inhibitors. This suggests that propofol might influence cellular events that are regulated by protein acetylation state. PMID:25666612

  14. Biosynthesis of optically pure chiral alcohols by a substrate coupled and biphasic system with a short-chain dehydrogenase from Streptomyces griseus.

    Science.gov (United States)

    Tan, Zhuotao; Ma, Hongmin; Li, Qing; Pu, Lingling; Cao, Yang; Qu, Xudong; Zhu, Chenjie; Ying, Hanjie

    2016-11-01

    The increasing demand for biocatalysts in synthesizing enantiomerically pure chiral alcohols results from the outstanding characteristics of enzymes in reaction, economic, ecological issues. Many carbonyl reductases for producing chiral alcohols have been reported but there is still a lack of good catalytic efficacies. Herein, five carbonyl reductases from different Streptomyces were discovered by the strategy of genome mining. These reductases were overexpressed, and we chose SgCR for further study as it owned better enzyme activity. This protein was purified to apparent homogeneity, and its amino acid sequence was analyzed in comparison with that of the reported SDRs. The biocatalytic properties of SgCR were investigated, and this enzyme was confirmed to have the ability to convert various prochiral ketones into highly optically active alcohols. SgCR exhibited the highest activity towards ethyl 4-chloro-3-oxobutanoate (COBE) and the corresponding product ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE) was obtained with high yield and excellent e.e. value by optimizing the biphasic system. Eventually, using isopropanol as the co-substrate for NADH recycling in the substrate-coupled reaction, the yield and enantioselectivity of (S)-CHBE were obtained at the values of 90% and 99%, respectively. These results indicate that SgCR is a promising boicatalyst for the synthesis of chiral alcohols in industry. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Overcoming the bottlenecks of anaerobic digestion of olive mill solid waste by two-stage fermentation.

    Science.gov (United States)

    Stoyanova, Elitza; Lundaa, Tserennyam; Bochmann, Günther; Fuchs, Werner

    2017-02-01

    Two-stage anaerobic digestion (AD) of two-phase olive mill solid waste (OMSW) was applied for reducing the inhibiting factors by optimizing the acidification stage. Single-stage AD and co-fermentation with chicken manure were conducted coinstantaneous for direct comparison. Degradation of the polyphenols up to 61% was observed during the methanogenic stage. Nevertheless the concentration of phenolic substances was still high; the two-stage fermentation remained stable at OLR 1.5 kgVS/m³day. The buffer capacity of the system was twice as high, compared to the one-stage fermentation, without additives. The two-stage AD was a combined process - thermophilic first stage and mesophilic second stage, which pointed out to be the most profitable for AD of OMSW for the reduced hydraulic retention time (HRT) from 230 to 150 days, and three times faster than the single-stage and the co-fermentation start-up of the fermentation. The optimal HRT and incubation temperature for the first stage were determined to four days and 55°C. The performance of the two-stage AD concerning the stability of the process was followed by the co-digestion of OMSW with chicken manure as a nitrogen-rich co-substrate, which makes them viable options for waste disposal with concomitant energy recovery.

  16. Artificial concurrent catalytic processes involving enzymes.

    Science.gov (United States)

    Köhler, Valentin; Turner, Nicholas J

    2015-01-11

    The concurrent operation of multiple catalysts can lead to enhanced reaction features including (i) simultaneous linear multi-step transformations in a single reaction flask (ii) the control of intermediate equilibria (iii) stereoconvergent transformations (iv) rapid processing of labile reaction products. Enzymes occupy a prominent position for the development of such processes, due to their high potential compatibility with other biocatalysts. Genes for different enzymes can be co-expressed to reconstruct natural or construct artificial pathways and applied in the form of engineered whole cell biocatalysts to carry out complex transformations or, alternatively, the enzymes can be combined in vitro after isolation. Moreover, enzyme variants provide a wider substrate scope for a given reaction and often display altered selectivities and specificities. Man-made transition metal catalysts and engineered or artificial metalloenzymes also widen the range of reactivities and catalysed reactions that are potentially employable. Cascades for simultaneous cofactor or co-substrate regeneration or co-product removal are now firmly established. Many applications of more ambitious concurrent cascade catalysis are only just beginning to appear in the literature. The current review presents some of the most recent examples, with an emphasis on the combination of transition metal with enzymatic catalysis and aims to encourage researchers to contribute to this emerging field.

  17. Assessment of two-phase olive mill solid waste and microalgae co-digestion to improve methane production and process kinetics.

    Science.gov (United States)

    Fernández-Rodríguez, M J; Rincón, B; Fermoso, F G; Jiménez, A M; Borja, R

    2014-04-01

    Olive mill solid waste (OMSW) is a pollutant waste coming from olive oil elaboration by the two-phase centrifugation system. OMSW has a high organic matter content and unbalanced carbon to nitrogen (C/N) ratio, 31/1, which avoids obtaining high methane yields in the anaerobic digestion of this waste. In the present study a microalgae, Dunaliella salina, was employed as co-substrate for the OMSW anaerobic digestion in order to decrease the C/N ratio and increase its biodegradability. Different co-digestion mixtures (C/N ratios) were studied. The increase of D. salina from 25% to 50% in the co-digestion mixture clearly increased the biodegradability of the sole substrates. The highest biodegradability was found for the co-digestion mixture 50% OMSW-50% D. salina. Nevertheless, the maximum methane production, 330mLCH4/gVSadded, and the highest methane production rate were obtained for the co-digestion mixture 75% OMSW-25% D. salina, keeping a C/N ratio near to 26.7/1.

  18. Investigation of the pharmacokinetic interactions of deferasirox, a once-daily oral iron chelator, with midazolam, rifampin, and repaglinide in healthy volunteers.

    Science.gov (United States)

    Skerjanec, Andrej; Wang, Jixian; Maren, Kelly; Rojkjaer, Lisa

    2010-02-01

    Deferasirox, a newly developed iron chelator, was coadministered orally with either a known inducer of drug metabolism or with cosubstrates for cytochrome P450 (CYP) to characterize the potential for drug-drug interactions. In the induction assessment, single-dose deferasirox pharmacokinetics were obtained in the presence and absence of a repeated-dose regimen of rifampin. In the CYP3A interaction evaluation, midazolam and its active hydroxylated metabolite were assessed after single doses of midazolam in the presence and absence of steady-state concentrations of deferasirox. To test for interaction at the level of CPY2C8, single-dose repaglinide pharmacokinetics/pharmacodynamics were determined with and without repeated-dose administration of deferasirox. After rifampin, a significant reduction (44%) in plasma exposure (AUC) to deferasirox was observed. Upon coadministration of midazolam, there was a modest reduction of up to 22% in midazolam exposure (AUC, C(max)), suggesting a modest induction of CYP3A4/5 by deferasirox. Def erasirox caused increases in repaglinide plasma C(max) and AUC of 1.5-fold to over 2-fold, respectively, with little change in blood glucose measures. Specific patient prescribing recommendations were established when coadministering deferasirox with midazolam, repaglinide, and rifampin. These recommendations may also apply to other substrates of CYP3A4/5 and CYP2C8 or potent inducers of glucuronidation.

  19. Mitigation of the inhibitory effect of soap by magnesium salt treatment of crude glycerol--a novel approach for enhanced biohydrogen production from the biodiesel industry waste.

    Science.gov (United States)

    Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Le Bihan, Yann; Buelna, Gerardo; Soccol, Carlos Ricardo

    2014-01-01

    Owing to its inhibitory effect on microbial growth, soap present in crude glycerol (CG) is a concern in biological valorization of the biodiesel manufacturing waste. By salting out strategy, up to 42% of the soap has been removed and the approach has beneficial effect on H2 production; however, removal of more than 7% of the soap was found to be inhibitory. Actually, soap is utilized as a co-substrate and due to removal; the carbon-nitrogen ratio of the medium might have decreased to reduce the production. Alternatively, without changing the carbon-nitrogen ratio of CG, MgSO4 treatment can convert the soap to its inactive form (scum). The approach was found to increase the H2 production rate (33.82%), cumulative H2 production (34.70%) as well as glycerol utilization (nearly 2.5-folds). Additionally, the treatment can increase the Mg (a nutrient) content of the medium from 0.57 ppm to 201.92 ppm.

  20. Polyhydroxyalkanoates (PHA) production from synthetic waste using Pseudomonas pseudoflava: PHA synthase enzyme activity analysis from P. pseudoflava and P. palleronii.

    Science.gov (United States)

    Venkateswar Reddy, M; Mawatari, Yasuteru; Onodera, Rui; Nakamura, Yuki; Yajima, Yuka; Chang, Young-Cheol

    2017-03-04

    Synthetic wastewater (SW) at various carbon concentrations (5-60g/l) were evaluated for polyhydroxyalkanoates (PHA) production using the bacteria Pseudomonas pseudoflava. Bacteria showed highest PHA production with 20g/l (57±5%), and highest carbon removal at 5g/l (74±6%) concentrations respectively. Structure, molecular weight, and thermal properties of the produced PHA were evaluated using various analytical techniques. Bacteria produced homo-polymer [poly-3-hydroxybutyrate (P3HB)] when only acetate was used as carbon source; and it produced co-polymer [poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV)] by addition of co-substrate propionate. PHA synthase, the enzyme which produce PHA was extracted from two bacterial strains i.e., P. pseudoflava and P. palleronii and its molecular weight was analysed using SDS-PAGE. Protein concentration, and PHA synthase enzyme activity of P. pseudoflava and P. palleronii was carried out using spectrophotometer. Results denoted that P. pseudoflava can be used for degradation of organic carbon persistent in wastewaters and their subsequent conversion into PHA.

  1. Pathways of reductive 2,4-dinitroanisole (DNAN) biotransformation in sludge.

    Science.gov (United States)

    Olivares, Christopher; Liang, Jidong; Abrell, Leif; Sierra-Alvarez, Reyes; Field, Jim A

    2013-06-01

    As the use of the insensitive munition compound 2,4-dinitroanisole (DNAN) increases, releases to the environment may pose a threat to local ecosystems. Little is known about the environmental fate of DNAN and the conversions caused by microbial activity. We studied DNAN biotransformation rates in sludge under aerobic, microaerophilic, and anaerobic conditions, detected biotransformation products, and elucidated their chemical structures. The biotransformation of DNAN was most rapid under anaerobic conditions with H2 as a cosubstrate. The results showed that the ortho nitro group in DNAN is regioselectively reduced to yield 2-methoxy-5-nitroaniline (MENA), and then the para nitro group is reduced to give 2,4-diaminoanisole (DAAN). Both MENA and DAAN were identified as important metabolites in all redox conditions. Azo and hydrazine dimer derivatives formed from the coupling of DNAN reduction products in anaerobic conditions. Secondary pathways included acetylation and methylation of amine moieties, as well as the stepwise O-demethylation and dehydroxylation of methoxy groups. Seven unique metabolites were identified which enabled elucidation of biotransformation pathways. The results taken as a whole suggest that reductive biotransformation is an important fate of DNAN leading to the formation of aromatic amines as well as azo and hydrazine dimeric metabolites.

  2. Evolutionary analysis of Slc11 mechanism of proton-coupled metal-ion transmembrane import

    Directory of Open Access Journals (Sweden)

    Mathieu F. M. Cellier

    2016-06-01

    Full Text Available Determination of the crystal structure of ScaDMT, a member of the Slc11 family, provided opportunity to advance understanding of proton-dependent metal-ion uptake by interfacing Slc11 molecular evolution and structural biology. Slc11 carriers belong to the ancient and broadly distributed APC superfamily characterized by the pseudo-symmetric LeuT-fold. This fold comprises two topologically inverted repeats (protomers that exchange alternate configurations during carrier cycling. Examining ScaDMT molecule inserted within a model membrane allowed to pinpoint residues that may interact with surrounding lipid solvent molecules. Three-dimensional mapping of Slc11-specific sites demonstrated they distribute at the protomer interface, along the transmembrane ion-conduction pathway. Functional sites were predicted by modeling hypothetical ScaDMT alternate conformers based on APC templates; these candidate homologous sites were found to co-localize with Slc11-specific sites, a distribution pattern that fits the functional diversity in the APC superfamily. Sites that diverged among eukaryotic Slc11 (Nramp types were located in transmembrane helices that may participate in discrete steps during co-substrate translocation, suggesting these sites influence transport activity. Adding some functional dimension to Slc11 carrier evolution will inform molecular understanding of metal-ion transport selectivity and regulation, Slc11 physiological roles and contribution to host resistance to microbial infection.

  3. Enhancement of Biogas Yield of Poplar Leaf by High-Solid Codigestion with Swine Manure.

    Science.gov (United States)

    Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

    2016-05-01

    The aim of this work was to examine the improvement of anaerobic biodegradability of organic fractions of poplar leaf from codigestion with swine manure (SM), thus biogas yield and energy recovery. When poplar leaf was used as a sole substrate, the cumulative biogas yield was low, about 163 mL (g volatile solid (VS))(-1) after 45 days of digestion with a substrate/inoculum ratio of 2.5 and a total solid (TS) of 22 %. Under the same condition, the cumulative biogas yield of poplar leaf reached 321 mL (g VS)(-1) when SM/poplar leaf ratio was 2:5 (based on VS). The SM/poplar leaf ratio can determine C/N ratio of the cosubstrate and thus has significant influence on biogas yield. When the SM/poplar leaf ratio was 2:5, C/N ratio was calculated to be 27.02, and the biogas yield in 45 days of digestion was the highest. The semi-continuous digestion of poplar leaf was carried out with the organic loading rate of 1.25 and 1.88 g VS day(-1). The average daily biogas yield was 230.2 mL (g VS)(-1) and 208.4 mL (g VS)(-1). The composition analysis revealed that cellulose and hemicellulose contributed to the biogas production.

  4. Crystal structure of the homocysteine methyltransferase MmuM from Escherichia coli.

    Science.gov (United States)

    Li, Kunhua; Li, Gengnan; Bradbury, Louis M T; Hanson, Andrew D; Bruner, Steven D

    2016-02-01

    Homocysteine S-methyltransferases (HMTs, EC 2.1.1.0) catalyse the conversion of homocysteine to methionine using S-methylmethionine or S-adenosylmethionine as the methyl donor. HMTs play an important role in methionine biosynthesis and are widely distributed among micro-organisms, plants and animals. Additionally, HMTs play a role in metabolite repair of S-adenosylmethionine by removing an inactive diastereomer from the pool. The mmuM gene product from Escherichia coli is an archetypal HMT family protein and contains a predicted zinc-binding motif in the enzyme active site. In the present study, we demonstrate X-ray structures for MmuM in oxidized, apo and metallated forms, representing the first such structures for any member of the HMT family. The structures reveal a metal/substrate-binding pocket distinct from those in related enzymes. The presented structure analysis and modelling of co-substrate interactions provide valuable insight into the function of MmuM in both methionine biosynthesis and cofactor repair.

  5. Myeloperoxidase: a target for new drug development?

    Science.gov (United States)

    Malle, E; Furtmüller, P G; Sattler, W; Obinger, C

    2007-11-01

    Myeloperoxidase (MPO), a member of the haem peroxidase-cyclooxygenase superfamily, is abundantly expressed in neutrophils and to a lesser extent in monocytes and certain type of macrophages. MPO participates in innate immune defence mechanism through formation of microbicidal reactive oxidants and diffusible radical species. A unique activity of MPO is its ability to use chloride as a cosubstrate with hydrogen peroxide to generate chlorinating oxidants such as hypochlorous acid, a potent antimicrobial agent. However, evidence has emerged that MPO-derived oxidants contribute to tissue damage and the initiation and propagation of acute and chronic vascular inflammatory disease. The fact that circulating levels of MPO have been shown to predict risks for major adverse cardiac events and that levels of MPO-derived chlorinated compounds are specific biomarkers for disease progression, has attracted considerable interest in the development of therapeutically useful MPO inhibitors. Today, detailed information on the structure of ferric MPO and its complexes with low- and high-spin ligands is available. This, together with a thorough understanding of reaction mechanisms including redox properties of intermediates, enables a rationale attempt in developing specific MPO inhibitors that still maintain MPO activity during host defence and bacterial killing but interfere with pathophysiologically persistent activation of MPO. The various approaches to inhibit enzyme activity of MPO and to ameliorate adverse effects of MPO-derived oxidants will be discussed. Emphasis will be put on mechanism-based inhibitors and high-throughput screening of compounds as well as the discussion of physiologically useful HOCl scavengers.

  6. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wijetunga, Somasiri, E-mail: swije2001@yahoo.com [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Li Xiufen [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Jian Chen, E-mail: jchen@sytu.edu.cn [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China)

    2010-05-15

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels ({approx}1000 mg/L, {approx}2000 mg/L, {approx}3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  7. Decolorization and biodegradation of reactive dyes and dye wastewater by a developed bacterial consortium.

    Science.gov (United States)

    Saratale, R G; Saratale, G D; Chang, J S; Govindwar, S P

    2010-11-01

    A bacterial consortium (consortium GR) consisting of Proteus vulgaris NCIM-2027 and Micrococcus glutamicus NCIM-2168 could rapidly decolorize and degrade commonly-used sulfonated reactive dye Green HE4BD and many other reactive dyes. Consortium GR shows markedly higher decolorization activity than that of the individual strains. The preferable physicochemical parameters were identified to achieve higher dye degradation and decolorization efficiency. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of consortium GR. Extent of mineralization was determined with TOC and COD measurements, showing nearly complete mineralization of Green HE4BD by consortium GR (up to 90% TOC and COD reduction) within 24 h. Oxidoreductive enzymes seemed to be involved in fast decolorization/degradation process with the evidence of enzymes induction in the bacterial consortium. Phytotoxicity and microbial toxicity studies confirm that the biodegraded products of Green HE4BD by consortium GR are non-toxic. Consortium GR also shows significant biodegradation and decolorization activities for mixture of reactive dyes as well as the effluent from actual dye manufacturing industry. This confers the possibility of applying consortium GR for the treatment of industrial wastewaters containing dye pollutants.

  8. Genomic and molecular mechanisms for efficient biodegradation of aromatic dye.

    Science.gov (United States)

    Sun, Su; Xie, Shangxian; Chen, Hu; Cheng, Yanbing; Shi, Yan; Qin, Xing; Dai, Susie Y; Zhang, Xiaoyu; Yuan, Joshua S

    2016-01-25

    Understanding the molecular mechanisms for aromatic compound degradation is crucial for the development of effective bioremediation strategies. We report the discovery of a novel phenomenon for improved degradation of Direct Red 5B azo dye by Irpex lacteus CD2 with lignin as a co-substrate. Transcriptomics analysis was performed to elucidate the molecular mechanisms of aromatic degradation in white rot fungus by comparing dye, lignin, and dye/lignin combined treatments. A full spectrum of lignin degradation peroxidases, oxidases, radical producing enzymes, and other relevant components were up-regulated under DR5B and lignin treatments. Lignin induced genes complemented the DR5B induced genes to provide essential enzymes and redox conditions for aromatic compound degradation. The transcriptomics analysis was further verified by manganese peroxidase (MnP) protein over-expression, as revealed by proteomics, dye decolorization assay by purified MnP and increased hydroxyl radical levels, as indicated by an iron reducing activity assay. Overall, the molecular and genomic mechanisms indicated that effective aromatic polymer degradation requires synergistic enzymes and radical-mediated oxidative reactions to form an effective network of chemical processes. This study will help to guide the development of effective bioremediation and biomass degradation strategies.

  9. EFFECT OF HIGH CONCENTRATIONS OF 2.4-DCP ON ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    Ayla Uysal

    2007-02-01

    Full Text Available Biodegradation of 2.4-dichlorophenol (2.4-DCP was investigated with a mixed culture in a continuous activated sludge bioreactor. Glucose was used as co-substrate. Experiments were carried out at the feed 2.4-DCP concentrations between 5-450 mg/l, and the removal efficiencies of 2.4-DCP and COD were determined. The removal efficiencies and specific removal rates of 2.4-DCP for feed 2.4-DCP concentration up to 350 mg/l varied between 96.3-98.6 % and 0.007-1.15 mg/mg X.day respectively. Removal efficiencies and specific removal rates ranged between 75.66-92.0 % and 0.43-1.29 mg/mg X.day for COD. When 2.4-DCP concentration was increased from 350 to 450 mg/l, the removal efficiency and specific removal rate of 2.4-DCP decreased to 42.6 % and 0.77 mg/mg X.day due to the substrate inhibition on the microorganisms. Also, these values decreased to 7.85 % and 0.18 mg/mg X.day for COD. These results indicate that the adaptation of activated sludge could tolerate as high as 350 mg/l 2.4-DCP concentration as to the removal of 2.4-DCP and COD.

  10. The 2.7 Å resolution structure of the glycopeptide sulfotransferase Teg14

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Matthew J. [Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Banik, Jacob J. [Howard Hughes Medical Institute, Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Darst, Seth A. [Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Brady, Sean F., E-mail: sbrady@rockefeller.edu [Howard Hughes Medical Institute, Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States)

    2010-12-01

    The 2.7 Å resolution crystal structure of Teg14, a glycopeptide sulfotransferase cloned from an uncultured soil bacterium, is described. The relationship of Teg14 to other sulfotransferases is discussed. The TEG gene cluster was recently isolated from an environmental DNA library and is predicted to encode the biosynthesis of a polysulfated glycopeptide congener. Three closely related sulfotransferases found in the TEG gene cluster (Teg12, Teg13 and Teg14) have been shown to sulfate the teicoplanin aglycone at three unique sites. Crystal structures of the first sulfotransferase from the TEG cluster, Teg12, in complex with the teicoplanin aglycone and its desulfated cosubstrate PAP have recently been reported [Bick et al. (2010 ▶), Biochemistry, 49, 4159–4168]. Here, the 2.7 Å resolution crystal structure of the apo form of Teg14 is reported. Teg14 sulfates the hydroxyphenylglycine at position 4 in the teicoplanin aglycone. The Teg14 structure is discussed and is compared with those of other bacterial 3′-phosphoadenosine 5′-phosphosulfate-dependent sulfotransferases facilitating crystallographic experiments, especially in the field of microcrystallography.

  11. Structural plasticity in the human cytosolic sulfotransferase dimer and its role in substrate selectivity and catalysis.

    Science.gov (United States)

    Tibbs, Zachary E; Rohn-Glowacki, Katie Jo; Crittenden, Frank; Guidry, Amber L; Falany, Charles N

    2015-02-01

    The cytosolic sulfotransferases (SULTs) are dimeric enzymes that help maintain homeostasis through the modulation of hormone and drug activity by catalyzing their transformation into hydrophilic sulfate esters and increasing their excretion. Each of the thirteen active human SULT isoforms displays a unique substrate specificity pattern that underlies its individual role in our bodies. These specificities have proven to be complex, in some cases masking the biological role of specific isoforms. The first part of this review offers a short summary of historical underpinnings of human SULTs, primarily centered on the characterization of each isoform's kinetic and structural properties. Recent structural investigations have revealed each SULT has an active site "lid" that undergoes restructuring once the cofactor/sulfonate donor, 3'-phosphoadenosine-5'-phosphosulfate (PAPS), binds to the enzyme. This structural rearrangement can alter substrate-binding profiles, therefore complicating enzyme/substrate interactions and making substrate/cosubstrate concentrations and binding order important considerations in enzyme functionality. Molecular dynamic simulations have recently been employed to describe this restructuring in an attempt to offer insight to its effects on substrate selectivity. In addition to reviewing new data on SULT molecular dynamics, we will discuss the contribution of PAPS concentrations and SULT dimerization in the regulation of SULT activity within the human body.

  12. Conditional iron and pH-dependent activity of a non-enzymatic glycolysis and pentose phosphate pathway.

    Science.gov (United States)

    Keller, Markus A; Zylstra, Andre; Castro, Cecilia; Turchyn, Alexandra V; Griffin, Julian L; Ralser, Markus

    2016-01-01

    Little is known about the evolutionary origins of metabolism. However, key biochemical reactions of glycolysis and the pentose phosphate pathway (PPP), ancient metabolic pathways central to the metabolic network, have non-enzymatic pendants that occur in a prebiotically plausible reaction milieu reconstituted to contain Archean sediment metal components. These non-enzymatic reactions could have given rise to the origin of glycolysis and the PPP during early evolution. Using nuclear magnetic resonance spectroscopy and high-content metabolomics that allowed us to measure several thousand reaction mixtures, we experimentally address the chemical logic of a metabolism-like network constituted from these non-enzymatic reactions. Fe(II), the dominant transition metal component of Archean oceanic sediments, has binding affinity toward metabolic sugar phosphates and drives metabolism-like reactivity acting as both catalyst and cosubstrate. Iron and pH dependencies determine a metabolism-like network topology and comediate reaction rates over several orders of magnitude so that the network adopts conditional activity. Alkaline pH triggered the activity of the non-enzymatic PPP pendant, whereas gentle acidic or neutral conditions favored non-enzymatic glycolytic reactions. Fe(II)-sensitive glycolytic and PPP-like reactions thus form a chemical network mimicking structural features of extant carbon metabolism, including topology, pH dependency, and conditional reactivity. Chemical networks that obtain structure and catalysis on the basis of transition metals found in Archean sediments are hence plausible direct precursors of cellular metabolic networks.

  13. Biogas generation apple pulp.

    Science.gov (United States)

    Llaneza Coalla, H; Blanco Fernández, J M; Morís Morán, M A; López Bobo, M R

    2009-09-01

    In view of the pressing problem that appears in our region (Asturias, north of Spain) with the residues from the cider production, it was decided to test this kind of material as a co-substrate joint with slaughterhouse waste in a laboratory unit. The anaerobic digestion of apple pulp was investigated for biogas production. This paper presents the results where apple pulp was co-digested with slaughterhouse waste (pig intestine and bovine stomach content) in a biogas laboratory unit (10 l CSTR reactor). The production of biogas has reached very satisfactory values during the whole test (0.8m(3)kg(-1)OTS), verifying that the process is kept in stable conditions of pH (near 8.0), and the volatile fatty acids was always underneath 3000 mg/l, when the pulp amount was lower than 100g in mesophilic conditions. The fat concentration into the digester remained always below the value that causes inhibition of the methanogenic bacteria, 500 mg/l. Finally, methane concentration (77-80%) and H(2)S concentration (400 ppm) in the biogas, they were similar to those obtained when the test was run out in the absence of apple pulp. The process efficiency with respect to COD removal was high, near 80% of the total COD. Finally, inhibitory effects of methanogenic bacteria were observed when pulp concentration was around 10% in the input material.

  14. Reaction Characteristics of Asymmetric Synthesis of (2S,5S)-2,5-Hexanediol Catalyzed with Baker's Yeast Number 6%面包酵母No.6催化不对称合成(2S,5S)-2,5-已二醇反应特性

    Institute of Scientific and Technical Information of China (English)

    肖美添; 叶静; 张亚武; 黄雅燕

    2009-01-01

    Baker's yeast number 6 was selected by screening. It showed good catalytic activity and enantioselec-tivity for asymmetric reduction of 2,5-hexancdione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spectrometry (GC-MS) revealed that the intermediate was (S)-5-hydroxyhexane-2-one. Reduction of 2,5-hexanedione proceeded in a two-step reaction. The hydroxyketone was initially formed, and this intermediate was further re-duced to the diol. Factors influencing the product yield and the enantiomeric excess of the reduction of 2,5-hexandione catalyzed by baker's yeast number 6 were investigated. Higher concentration (≤100 mmol·L-1) of 2,5-hexandione did not influence 5-hydroxyhexane-2-one production, but 2,5-hexanediol production was inhibited by excess accumulation (>30 mmol·L-1) of intermediate. The optimal conditions were glucose as the co-substrate at an initial glucose concentration of 20 g·L-1, 34℃, pH 7.0 and cell concentration 60 g-L"1 (cell dry mass). Under the optimal condition and an initial substrate concentration of 30 mmol·L-1, the yield of 2,5-hexandiol was 78.7% and the enantiomeric excess of (2S,5S)-2,5-hexandiol was 94.4% for 24-h reduction.

  15. Consecutive anaerobic-aerobic treatment of the organic fraction of municipal solid waste and lignocellulosic materials in laboratory-scale landfill-bioreactors.

    Science.gov (United States)

    Pellera, Frantseska-Maria; Pasparakis, Emmanouil; Gidarakos, Evangelos

    2016-10-01

    The scope of this study is to evaluate the use of laboratory-scale landfill-bioreactors, operated consecutively under anaerobic and aerobic conditions, for the combined treatment of the organic fraction of municipal solid waste (OFMSW) with two different co-substrates of lignocellulosic nature, namely green waste (GW) and dried olive pomace (DOP). According to the results such a system would represent a promising option for eventual larger scale applications. Similar variation patterns among bioreactors indicate a relatively defined sequence of processes. Initially operating the systems under anaerobic conditions would allow energetic exploitation of the substrates, while the implementation of a leachate treatment system ultimately aiming at nutrient recovery, especially during the anaerobic phase, could be a profitable option for the whole system, due to the high organic load that characterizes this effluent. In order to improve the overall effectiveness of such a system, measures towards enhancing methane contents of produced biogas, such as substrate pretreatment, should be investigated. Moreover, the subsequent aerobic phase should have the goal of stabilizing the residual materials and finally obtain an end material eventually suitable for other purposes.

  16. Fermentation of pulp from coffee production; Vergaerung von Pulpa aus der Kaffee-Produktion

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, M.; Baier, U.

    2003-07-01

    Harvesting of coffee berries and production of dried coffee beans produces large amounts of solid wastes. Per ton of consumable coffee beans, roughly 2 tons of spent coffee pulp are wasted at the production facilities. Coffee pulp represents a valuable source of energy and can be used for anaerobic biogas production. In this study it was shown that coffee pulp can be anaerobically digested as a sole carbon source without further addition of co-substrates. No nutrient limitations and only a very moderate substrate inhibition have been found in concentrated pulp. The mesophilic biogas formation potential was found to be 0.38 m{sup 3} biogas per kg of organic matter. The anaerobic degradability was higher than 70%. In semi-continuously operated biogas reactors a high degradation of organics and a subsequent biogas production was shown at hydraulic detention times of 16 days. Methanization of fresh pulp is technically feasible in fully mixed tank reactors as well as in plug flow reactors. Due to the presence of easily degradable carbon sources, fresh pulp will quickly show microbiological growth. Storage in the presence of ambient oxygen will result in aerobic degradation of organics in parallel with energy loss. Additionally, anaerobic zones with methane emission will quickly occur. Therefore, it is recommended to store fresh pulp under oxygen free, lactic acid conditions (silage) until anaerobic treatment in the biogas reactor. (author)

  17. (R,R)-Butane-2,3-diol dehydrogenase from Bacillus clausii DSM 8716(T): Cloning and expression of the bdhA-gene, and initial characterization of enzyme.

    Science.gov (United States)

    Muschallik, Lukas; Molinnus, Denise; Bongaerts, Johannes; Pohl, Martina; Wagner, Torsten; Schöning, Michael J; Siegert, Petra; Selmer, Thorsten

    2017-09-20

    The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716(T) was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33-43%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12U/mg and 23U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD(+) was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development. Copyright © 2017. Published by Elsevier B.V.

  18. Glutamine inhibits ammonia-induced accumulation of cGMP in rat striatum limiting arginine supply for NO synthesis.

    Science.gov (United States)

    Hilgier, Wojciech; Freśko, Inez; Klemenska, Emilia; Beresewicz, Andrzej; Oja, Simo S; Saransaari, Pirjo; Albrecht, Jan; Zielińska, Magdalena

    2009-07-01

    Brain L-glutamine (Gln) accumulation and increased activity of the NO/cGMP pathway are immediate consequences of acute exposure to ammonia. This study tested whether excess Gln may influence NO and/or cGMP synthesis. Intrastriatal administration of the glutaminase inhibitor 6-diazo-5-oxo-L-norleucine or the system A-specific Gln uptake inhibitor methylaminoisobutyrate increased microdialysate Gln concentration and reduced basal and ammonia-induced NO and cGMP accumulation. Gln applied in vivo (via microdialysis) or in vitro (to rat brain cortical slices) reduced NO and cGMP accumulation in the presence and/or absence of ammonia, but not cGMP synthesis induced by the NO donor sodium nitroprusside. Attenuation of cGMP synthesis by Gln was prevented by administration of L-arginine (Arg). The L-arginine co-substrates of y(+)LAT2 transport system, L-leucine and cyclo-leucine, mimicked the effect of exogenous Gln, suggesting that Gln limits Arg supply for NO synthesis by interfering with y+LAT2-mediated Arg uptake across the cell membrane.

  19. Determination of biogas generation potential as a renewable energy source from supermarket wastes.

    Science.gov (United States)

    Alkanok, Gizem; Demirel, Burak; Onay, Turgut T

    2014-01-01

    Fruit, vegetable, flower waste (FVFW), dairy products waste (DPW), meat waste (MW) and sugar waste (SW) obtained from a supermarket chain were anaerobically digested, in order to recover methane as a source of renewable energy. Batch mesophilic anaerobic reactors were run at total solids (TS) ratios of 5%, 8% and 10%. The highest methane yield of 0.44 L CH4/g VS(added) was obtained from anaerobic digestion of wastes (FVFW+DPW+MW+SW) at 10% TS, with 66.4% of methane (CH4) composition in biogas. Anaerobic digestion of mixed wastes at 5% and 8% TS provided slightly lower methane yields of 0.41 and 0.40 L CH4/g VS(added), respectively. When the wastes were digested alone without co-substrate addition, the highest methane yield of 0.40 L CH4/g VS(added) was obtained from FVFW at 5% TS. Generally, although the volatile solids (VS) conversion percentages seemed low during the experiments, higher methane yields could be obtained from anaerobic digestion of supermarket wastes. A suitable carbon/nitrogen (C/N) ratio, proper adjustment of the buffering capacity and the addition of essential trace nutrients (such as Ni) could improve VS conversion and biogas production yields significantly.

  20. Efficient carbon dioxide utilization and simultaneous hydrogen enrichment from off-gas of acetone-butanol-ethanol fermentation by succinic acid producing Escherichia coli.

    Science.gov (United States)

    He, Aiyong; Kong, Xiangping; Wang, Chao; Wu, Hao; Jiang, Min; Ma, Jiangfeng; Ouyang, Pingkai

    2016-08-01

    The off-gas from acetone-butanol-ethanol (ABE) fermentation was firstly used to be CO2 source (co-substrate) for succinic acid production. The optimum ratio of H2/CO2 indicated higher CO2 partial pressures with presence of H2 could enhance C4 pathway flux and reductive product productivity. Moreover, when an inner recycling bioreactor was used for CO2 recycling at a high total pressure (0.2Mpa), a maximum succinic acid concentration of 65.7g·L(-1) was obtained, and a productivity of 0.76g·L(-1)·h(-1) and a high yield of 0.86g·g(-1) glucose were achieved. Furthermore, the hydrogen content was simultaneously enriched to 92.7%. These results showed one successful attempt to reuse the off-gas of ABE fermentation which can be an attractive CO2 source for succinic acid production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A synthetic model for the inhibition of glutathione peroxidase by antiarthritic gold compounds.

    Science.gov (United States)

    Bhabak, Krishna P; Mugesh, Govindasamy

    2009-03-16

    In this paper, inhibition of the glutathione peroxidase activity of two synthetic organoselenium compounds, bis[2-(N,N-dimethylamino)benzyl]diselenide (5) and bis[2-(N,N-dimethylamino)benzyl]selenide (9), by gold(I) thioglucose (1), chloro(triethylphosphine)gold(I), chloro(trimethylphosphine)gold(I), and chloro(triphenylphosphine)gold(I) is described. The inhibition is found to be competitive with respect to a peroxide (H(2)O(2)) substrate and noncompetitive with respect to a thiol (PhSH) cosubstrate. The diselenide 5 reacts with PhSH to produce the corresponding selenol (6), which upon treatment with 1 equiv of gold(I) chlorides produces the corresponding gold selenolate complexes 11-13. However, the addition of 1 equiv of selenol 6 to complexes 11-13 leads to the formation of bis-selenolate complex 14 by ligand displacement reactions involving the elimination of phosphine ligands. The phosphine ligands eliminated from these reactions are further converted to the corresponding phosphine oxides (R(3)P=O) and selenides (R(3)P=Se). In addition to the replacement of the phosphine ligand by selenol 6, an interchange between two different phosphine ligands is also observed. For example, the reaction of complex 11 having a trimethylphosphine ligand with triphenylphosphine produces complex 13 by phosphine interchange reactions via the formation of intermediates 15 and 16. The reactivity of selenol 6 toward gold(I) phosphines is found to be similar to that of selenocysteine.

  2. Anaerobic co-digestion of cyanide containing cassava pulp with pig manure.

    Science.gov (United States)

    Glanpracha, Naraporn; Annachhatre, Ajit P

    2016-08-01

    Anaerobic co-digestion of cyanide-containing cassava pulp with pig manure was evaluated using laboratory scale mesophilic digester. The digester was operated in a semi-continuous mode with the mixed feedstock having C/N ratio of 35:1. Digester startup was accomplished in 60days with loading of 0.5-1kgVS/m(3)d. Subsequently, the loading to digester was increased step-wise from 2 to 9kgVS/m(3)d. Digester performance was stable at loading between 2 and 6kgVS/m(3)d with an average volatile solid removal and methane yield of 82% and 0.38m(3)/kgVSadded, respectively. However, beyond loading of 7kgVS/m(3)d, solubilization of particulate matter did not take place efficiently. Cyanide present in cassava pulp was successfully degraded indicating that anaerobic sludge in the digester was well acclimatized to cyanide. The results show that cassava pulp can be successfully digested anaerobically with pig manure as co-substrate without any inhibitory effect of cyanide present in the cassava pulp.

  3. Microbial community structure and performance of an anaerobic reactor digesting cassava pulp and pig manure.

    Science.gov (United States)

    Panichnumsin, P; Ahring, B; Nopharatana, A; Chaiprasert, P

    2012-01-01

    Microbial community dynamics in response to changes in substrate types (i.e. pig manure (PM), cassava pulp (CP) and mixtures of PM and CP) were investigated in an anaerobic continuously stirred tank reactor (CSTR). Molecular identification of bacterial and archaeal domains were performed, using a 16S rDNA clone library with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) screening and phylogenetic analysis. Analysis of bacterial clone libraries revealed that the differences in the community structure corresponded to the substrate types. However, the Bacteroidetes were the most abundant group in all substrates, followed by the Clostridia. With pure PM, the dominant bacterial groups were Bacteroidales, Clostridia and Paludibacter. With a co-substrate, at CP to PM (CP:PM) ratio of 50:50, the sequences analysis revealed the greatest diversity of bacterial communities at class level, and the sequences affiliated with Cytophaga sp. became an exclusive predominant. With CP alone, Bacteroides sp. was the dominant species and this reactor had the lowest diversity of bacteria. Archaea observed in the CSTR fed with all substrate types were Methanosaeta sp., Methanosaeta concilii and Methanospirillum hungatei. Among the Archaea, Methanosaeta sp. was the exclusive predominant. The relative distribution of Archaea also changed regarding to the substrate types.

  4. Anaerobic treatment of olive mill wastewater and piggery effluents fermented with Candida tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Garcia, Gregorio [Department of Chemical and Process Engineering, University of Sheffield, S1 3JD Sheffield (United Kingdom); Johnson, Anbu Clemensis, E-mail: acj265@yahoo.com [Department of Chemical and Process Engineering, University of Sheffield, S1 3JD Sheffield (United Kingdom)] [School of Environmental Engineering, Universiti Malaysia Perlis, 02600 Jejawi, Perlis (Malaysia); Bachmann, Robert T. [Department of Chemical and Process Engineering, University of Sheffield, S1 3JD Sheffield (United Kingdom)] [Malaysian Institute of Chemical and Bioengineering Technology, Universiti Kuala Lumpur, 1988 Vendor City, 7800 Taboh Naning, Alor Gajah, Melaka (Malaysia); Williams, Ceri J. [Yorkshire-Forward, Victoria House, Victoria Place, LS11 5AE Leeds (United Kingdom); Burgoyne, Andrea; Edyvean, Robert G.J. [Department of Chemical and Process Engineering, University of Sheffield, S1 3JD Sheffield (United Kingdom)

    2009-05-30

    Olive mill wastewater (OMW) contains high concentrations of phenolic compounds that are inhibitory to many microorganisms making it difficult to treat biologically prior to discharge in waterways. The total mono-cyclic phenol reduction in OMW in this study was carried out by aerobic pre-treatment using the yeast Candida tropicalis in a 18 L batch reactor at 30 deg. C for 12 days followed by anaerobic co-digestion. A COD removal of 62% and a reduction in the total mono-cyclic phenol content by 51% of the mixture was achieved in the aerobic pre-treatment. Pig slurry was added as co-substrate to supplement the low nitrogen levels in the olive mill wastewater. Subsequent anaerobic treatment was carried out in a 20 L fixed-bed reactor at 37 deg. C and HRT between 11 and 45 days. After a long start-up period, the OLR was increased from 1.25 to 5 kg COD m{sup -3} day{sup -1} during the last 30 days, resulting in subsequent increase in overall COD removal and biogas production, up to maximum values of 85% and 29 L{sub biogas}L{sub reactor}{sup -1}day{sup -1}, respectively. Methane content of the biogas produced from the anaerobic digestion ranged between 65% and 74%.

  5. Substrate profiling of glutathione S-transferase with engineered enzymes and matched glutathione analogues.

    Science.gov (United States)

    Feng, Shan; Zhang, Lei; Adilijiang, Gulishana; Liu, Jieyuan; Luo, Minkui; Deng, Haiteng

    2014-07-01

    The identification of specific substrates of glutathione S-transferases (GSTs) is important for understanding drug metabolism. A method termed bioorthogonal identification of GST substrates (BIGS) was developed, in which a reduced glutathione (GSH) analogue was developed for recognition by a rationally engineered GST to label the substrates of the corresponding native GST. A K44G-W40A-R41A mutant (GST-KWR) of the mu-class glutathione S-transferases GSTM1 was shown to be active with a clickable GSH analogue (GSH-R1) as the cosubstrate. The GSH-R1 conjugation products can react with an azido-based biotin probe for ready enrichment and MS identification. Proof-of-principle studies were carried to detect the products of GSH-R1 conjugation to 1-chloro-2,4-dinitrobenzene (CDNB) and dopamine quinone. The BIGS technology was then used to identify GSTM1 substrates in the Chinese herbal medicine Ganmaocongji.

  6. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Eiteman

    2005-11-01

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The first phase of this research has focused on strain development and on process development. Progress in strain development has been made in three areas. The gene encoding for alcohol dehydrogenase has been ''knocked out'' of the bacteria, and thereby eliminating the synthesis of the by-product ethanol. The gene for glucokinase has been overexpressed in the production strain with the goal of faster utilization of glucose (and hence CO{sub 2}). Efforts have continued toward integrating pyruvate carboxylase gene (pyc) onto the E. coli chromosome. Progress in process development has come in conducting several dozen fermentation experiments to find a defined medium that would be successful for the growth of the bacteria, while permitting a high rate of CO{sub 2} utilization in a subsequent prolonged production phase. Using this defined medium, the strains that continue to be constructed are being compared for CO{sub 2} utilization, so that we may understand the factors that govern the biological sequestration process.

  7. Ethylene-Regulated Glutamate Dehydrogenase Fine-Tunes Metabolism during Anoxia-Reoxygenation.

    Science.gov (United States)

    Tsai, Kuen-Jin; Lin, Chih-Yu; Ting, Chen-Yun; Shih, Ming-Che

    2016-11-01

    Ethylene is an essential hormone in plants that is involved in low-oxygen and reoxygenation responses. As a key transcription factor in ethylene signaling, ETHYLENE INSENSITIVE3 (EIN3) activates targets that trigger various responses. However, most of these targets are still poorly characterized. Through analyses of our microarray data and the published Arabidopsis (Arabidopsis thaliana) EIN3 chromatin immunoprecipitation sequencing data set, we inferred the putative targets of EIN3 during anoxia-reoxygenation. Among them, GDH2, which encodes one subunit of glutamate dehydrogenase (GDH), was chosen for further studies for its role in tricarboxylic acid cycle replenishment. We demonstrated that both GDH1 and GDH2 are induced during anoxia and reoxygenation and that this induction is mediated via ethylene signaling. In addition, the results of enzymatic assays showed that the level of GDH during anoxia-reoxygenation decreased in the ethylene-insensitive mutants ein2-5 and ein3eil1 Global metabolite analysis indicated that the deamination activity of GDH might regenerate 2-oxoglutarate, which is a cosubstrate that facilitates the breakdown of alanine by alanine aminotransferase when reoxygenation occurs. Moreover, ineffective tricarboxylic acid cycle replenishment, disturbed carbohydrate metabolism, reduced phytosterol biosynthesis, and delayed energy regeneration were found in gdh1gdh2 and ethylene mutants during reoxygenation. Taken together, these data illustrate the essential role of EIN3-regulated GDH activity in metabolic adjustment during anoxia-reoxygenation.

  8. Fe(II)EDTA-NO reduction coupled with Fe(II)EDTA oxidation by a nitrate- and Fe(III)-reducing bacterium.

    Science.gov (United States)

    Dong, Xiyang; Zhang, Yu; Zhou, Jiti; Chen, Mingxiang; Wang, Xiaojun; Shi, Zhuang

    2013-06-01

    The nitrate- and Fe(III)-reducing bacterium Paracoccus versutus LYM was characterized in terms of its ability to perform Fe(II)EDTA-NO reduction coupled with Fe(II)EDTA oxidation (NO-dependent Fe(II)EDTA oxidation, NDFO). It experienced a single anaerobic FeEDTA redox cycling through NDFO and dissimilatory Fe(III)EDTA reduction in FeEDTA culture. The increase in the Fe(II)EDTA concentration contributed to the ascending Fe(II)EDTA-NO reduction rate. The amount of glucose controlled the rate and extent of Fe(II) oxidation during NDFO. Without glucose addition, Fe(II)EDTA-NO reduction rate was at a rather slow rate even in presence of relatively sufficient Fe(II)EDTA. Unlike aqueous Fe(2+) and solid-phase Fe(II), Fe(II)EDTA could prevent cells from encrustations. These findings suggested the occurrence of NDFO preferred being beneficial via a mixotrophic physiology in the presence of an organic cosubstrate to being out of consideration for metabolic strategy.

  9. Sirtuin 1 is a key regulator of the interleukin-12 p70/interleukin-23 balance in human dendritic cells.

    Science.gov (United States)

    Alvarez, Yolanda; Rodríguez, Mario; Municio, Cristina; Hugo, Etzel; Alonso, Sara; Ibarrola, Nieves; Fernández, Nieves; Crespo, Mariano Sánchez

    2012-10-12

    Stimulation of human dendritic cells with the fungal surrogate zymosan produces IL-23 and a low amount of IL-12 p70. Trans-repression of il12a transcription, which encodes IL-12 p35 chain, by proteins of the Notch family and lysine deacetylation reactions have been reported as the underlying mechanisms, but a number of questions remain to be addressed. Zymosan produced the location of sirtuin 1 (SIRT1) to the nucleus, enhanced its association with the il12a promoter, increased the nuclear concentration of the SIRT1 co-substrate NAD(+), and decreased chromatin accessibility in the nucleosome-1 of il12a, which contains a κB-site. The involvement of deacetylation reactions in the inhibition of il12a transcription was supported by the absence of Ac-Lys-14-histone H3 in dendritic cells treated with zymosan upon coimmunoprecipitation of transducin-like enhancer of split. In contrast, we did not obtain evidence of a possible effect of SIRT1 through the deacetylation of c-Rel, the central element of the NF-κB family involved in il12a regulation. These data indicate that an enhancement of SIRT1 activity in response to phagocytic stimuli may reduce the accessibility of c-Rel to the il12a promoter and its transcriptional activation, thus regulating the IL-12 p70/IL-23 balance and modulating the ongoing immune response.

  10. Sirtuin 1 Is a Key Regulator of the Interleukin-12 p70/Interleukin-23 Balance in Human Dendritic Cells*

    Science.gov (United States)

    Alvarez, Yolanda; Rodríguez, Mario; Municio, Cristina; Hugo, Etzel; Alonso, Sara; Ibarrola, Nieves; Fernández, Nieves; Crespo, Mariano Sánchez

    2012-01-01

    Stimulation of human dendritic cells with the fungal surrogate zymosan produces IL-23 and a low amount of IL-12 p70. Trans-repression of il12a transcription, which encodes IL-12 p35 chain, by proteins of the Notch family and lysine deacetylation reactions have been reported as the underlying mechanisms, but a number of questions remain to be addressed. Zymosan produced the location of sirtuin 1 (SIRT1) to the nucleus, enhanced its association with the il12a promoter, increased the nuclear concentration of the SIRT1 co-substrate NAD+, and decreased chromatin accessibility in the nucleosome-1 of il12a, which contains a κB-site. The involvement of deacetylation reactions in the inhibition of il12a transcription was supported by the absence of Ac-Lys-14-histone H3 in dendritic cells treated with zymosan upon coimmunoprecipitation of transducin-like enhancer of split. In contrast, we did not obtain evidence of a possible effect of SIRT1 through the deacetylation of c-Rel, the central element of the NF-κB family involved in il12a regulation. These data indicate that an enhancement of SIRT1 activity in response to phagocytic stimuli may reduce the accessibility of c-Rel to the il12a promoter and its transcriptional activation, thus regulating the IL-12 p70/IL-23 balance and modulating the ongoing immune response. PMID:22893703

  11. Enhanced chrysene degradation by halotolerant Achromobacter xylosoxidans using Response Surface Methodology.

    Science.gov (United States)

    Ghevariya, Chirag M; Bhatt, Jwalant K; Dave, Bharti P

    2011-10-01

    Degradation of chrysene, a four ring High Molecular Weight (HMW) Polycyclic Aromatic Hydrocarbon (PAH) is of intense environmental interest, being carcinogenic, teratogenic and mutagenic. Multiple PAH degrading halotolerant Achromobacter xylosoxidans was isolated from crude oil polluted saline site. Response Surface Methodology (RSM) using Central Composite Design (CCD) of Bushnell-Haas medium components was successfully employed for optimization resulting 40.79% chrysene degradation on 4th day. The interactions between variables as chrysene and glucose concentrations, pH and inoculum size on degradation were examined by RSM. Under optimum conditions, A. xylosoxidans exhibited 85.96% chrysene degradation on 5th day. The optimum values predicted by RSM were confirmed through confirmatory experiments. It was also noted that pH and glucose as co-substrate play a dynamic role in enhancement of chrysene degradation. Hence, A. xylosoxidans can be further used for subsequent microcosm and in situ experiments for its potential to remediate PAH contaminated saline and non-saline soils.

  12. Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin.

    Science.gov (United States)

    Nakamura, Kazuhiro; Hasegawa, Hiroyuki

    2009-01-01

    Serotonin (5-hydroxytryptamine [5-HT]) has been implicated in a variety of physiological and pathological functions. Multiple steps of enzyme reactions enable biosynthesis of 5-HT. The first and rate-limiting step of the reaction is the synthesis of 5-hydroxy-L-tryptophan (5-HTP) from L-tryptophan. This step is dictated by an enzyme, tryptophan hydroxylase (TPH). TPH requires 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as a co-substrate of TPH. 5-HTP has been simply regarded as a precursor of 5-HT and it is believed that the biological significance of 5-HTP is essentially ascribed to the production of 5-HT. However, recent works shed light on the specific functions of 5-HTP in the periphery. In this review article, we focus on the specific roles of exogenous 5-HTP as well as the endogenous 5-HTP in the gut epithelial cells. Since systemic treatment with 5-HTP is applied to patients with lower 5-HT levels, the studies on the specific role of 5-HTP might create an opportunity to explore the effects of exogenously-applied 5-HTP in the gut in man.

  13. Ascorbic acid: its role in immune system and chronic inflammation diseases.

    Science.gov (United States)

    Sorice, Angela; Guerriero, Eliana; Capone, Francesca; Colonna, Giovanni; Castello, Giuseppe; Costantini, Susan

    2014-05-01

    Ascorbic acid (AA), also known as vitamin C, was initially identified as the factor preventing the scurvy disease, and became very popular for its antioxidant properties. It is an important co-substrate of a large class of enzymes, and regulates gene expression by interacting with important transcription factors. AA is important in all stressful conditions that are linked to inflammatory processes and involve immunity. It has been known for decades that the persistence of an inflammatory stimulus is responsible for the onset of many diseases. AA is essential to stimulate the immune system by increasing the strength and protection of the organism. Therefore, its immunostimulant, antinflammatory, antiviral and antibacterial roles are well known, we have summarized its main functions in different types of diseases related to the immune system and chronic inflammation. We can conclude that AA, due to its effects and diversity of regulated pathways, is suitable for use in various fields of medicine including immunology, toxicology, radiobiology and others. AA is not preferable to be used as an isolated mode of treatment, but it can be co-applied as an adjuvant to regulate immunity, gene expression and other important physiological processes. However, we propose that future studies will take into consideration the research of new combinations of antioxidant natural substances and drugs.

  14. Bioremediation of kerosene I: A case study in liquid media.

    Science.gov (United States)

    Gouda, Mona K; Omar, Sanaa H; Chekroud, Zohra A; Nour Eldin, Hemdan M

    2007-11-01

    The ability of different local isolates in addition to some isolates from Germany to degrade kerosene in liquid medium was studied. The results showed that the percent of kerosene degradation varied among the different organisms and that 59-94% of kerosene was degraded after 21d. Two local isolates (Pseudomonas sp. AP and Pseudomonas sp. CK) and one German isolate (Gordonia sp. DM) were selected for this study. The addition of wheat bran, as co-substrate, stimulated the kerosene degradation by the two local strains, while glucose inhibited the degradation rate using the three organisms with different rates. Ammonium nitrate and urea was the best nitrogen sources. The use of superphosphate (as phosphorus source) in the presence of urea stimulates the degradation rate. It was also observed that the addition of 1% surfactants, like Triton X-100, Igepal, Tergitol, or Tween 20 and 80 enhanced the kerosene degradation. The degradation percent lied between 94% and 98%. The ability of the tested organisms to degrade kerosene concentration from 2% to 8% was evaluated. It was found that the three organisms degraded about 65-85% from 8% kerosene after 21d. The use of rice straw-immobilized cells reduced the time of degradation and enhanced the degradation ability of the organisms. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of a common protein band when the tested organisms were grown on kerosene.

  15. Decolorization and detoxification of sulfonated azo dye C.I. Remazol Red and textile effluent by isolated Lysinibacillus sp. RGS.

    Science.gov (United States)

    Saratale, Rijuta G; Gandhi, Soniya S; Purankar, Madhavi V; Kurade, Mayur B; Govindwar, Sanjay P; Oh, Sang Eun; Saratale, Ganesh D

    2013-06-01

    A novel bacterium was isolated from the soil of Ichalkaranji textile industrial area. Through 16S rRNA sequence matching and morphological observation it was identified as Lysinibacillus sp. RGS. This strain has ability to decolorize various industrial dyes among which, it showed complete decolorization and degradation of toxic sulfonated azo dye C.I. Remazol Red (at 30°C, pH 7.0, under static condition) with higher chemical oxygen demand (COD) reduction (92%) within 6 h of incubation. Various parameters like agitation, pH, temperature and initial dye concentrations were optimized to develop faster decolorization process. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of Lysinibacillus sp. RGS. Induction in oxidoreductive enzymes presumably indicates involvement of these enzymes in the decolorization/degradation process. Analytical studies of the extracted metabolites confirmed the significant degradation of Remazol Red into various metabolites. The phytotoxicity assay (with respect to plants Phaseolus mungo and Sorghum vulgare) revealed that the degradation of Remazol Red produced nontoxic metabolites. Finally Lysinibacillus sp. RGS was applied to decolorize mixture of dyes and actual industrial effluent showing 87% and 72% decolorization (in terms of decrease in ADMI value) with 69% and 62% COD reduction within 48 h and 96 h, respectively. The foregoing result increases the applicability of the strain for the treatment of industrial wastewaters containing dye pollutants.

  16. Key factors regarding decolorization of synthetic anthraquinone and azo dyes.

    Science.gov (United States)

    Boonyakamol, A; Imai, T; Chairattanamanokorn, P; Higuchi, T; Sekine, M

    2009-07-01

    The factors affecting decolorization of anthraquinone dye represented by Reactive Blue 4 (RB4) and azo dye represented by Methyl Orange (MO) were studied in batch experiments under mesophilic (35 degrees C) and thermophilic (55 degrees C) anaerobic conditions. The results indicated differences in decolorization properties of the dyes with different chromophore structures. In abiotic conditions, MO could be decolorized by a physicochemical reaction when it was sterilized at 121 degrees C together with sludge cells or glucose. RB4 only showed absorption onto the cell mass. The presence of a redox mediator accelerated the decolorizing reaction when supplied together with glucose in the presence of sterilized sludge cells. In biotic conditions, the results indicated that the biological activity of microorganisms was an important factor in decolorization. The main factor involved in decolorization was the conversion of cosubstrate as electron donor, which reacted with dye as an electron acceptor in electron transfer. Redox mediators, anthraquinone-2-sulfonic acid, and anthraquinone could accelerate decolorization even if a small amount (0.2 mM) was applied. On the other hand, a high concentration of redox mediator (1.0 mM) had an inhibitory effect on decolorization especially under thermophilic conditions. In addition, the decolorization of dye was accelerated by increasing treatment temperature, as shown in biotic treatments. Based on these results, increasing the treatment temperature could be used to improve the decolorizing process of textile dye wastewater treatment, especially for recalcitrant dyes such as anthraquinone.

  17. Decolorization of azo dyes in bioelectrochemical systems.

    Science.gov (United States)

    Mu, Yang; Rabaey, Korneel; Rozendal, René A; Yuan, Zhiguo; Keller, Jürg

    2009-07-01

    Azo dyes are ubiquitously used in the textile industry. These dyes need to be removed from the effluent prior to discharge to sewage due to their intense color and toxicity. In this study we investigated the use of a bioelectrochemical system (BES) to abioticlly cathodic decolorization of a model azo dye, Acid Orange 7 (AO7), where the process was driven by microbial oxidation of acetate atthe anode. Effective decolorization of AO7 at rates up to 264 +/- 0.03 mol m(-3) NCC d(-1) (net cathodic compartment, NCC) was achieved at the cathode, with concomitant energy recovery. The AO7 decolorization rate was significantly enhanced when the BES was supplied with power, reaching 13.18 +/- 0.05 mol m(-3) NCC d(-1) at an energy consumption 0.012 +/- 0.001 kWh mol(-1) AO7 (at a controlled cathode potential of -400 mV vs SHE). Compared with conventional anaerobic biological methods, the required dosage of organic cosubstrate was significantly reduced in the BES. A possible cathodic reaction mechanism for the decolorization of AO7 is suggested based on the decolorization products identified: the azo bond of AO7 was cleaved at the cathode, resulting in the formation of the colorless sulfanilic acid and 1-amino-2-naphthol.

  18. Microbial decolorization of reactive black-5 in a two-stage anaerobic-aerobic reactor using acclimatized activated textile sludge.

    Science.gov (United States)

    Mohanty, Sagarika; Dafale, Nishant; Rao, Nageswara Neti

    2006-10-01

    A two-stage anaerobic-aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l(-1). The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by > 90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l(-1 )and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV-VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic-aerobic treatment after a reaction period of 2 days.

  19. Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

    2014-01-01

    The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

  20. An integrated bioremediation process for petroleum hydrocarbons removal and odor mitigation from contaminated marine sediment.

    Science.gov (United States)

    Zhang, Zhen; Lo, Irene M C; Yan, Dickson Y S

    2015-10-15

    This study developed a novel integrated bioremediation process for the removal of petroleum hydrocarbons and the mitigation of odor induced by reduced sulfur from contaminated marine sediment. The bioremediation process consisted of two phases. In Phase I, acetate was dosed into the sediment as co-substrate to facilitate the sulfate reduction process. Meanwhile, akaganeite (β-FeOOH) was dosed in the surface layer of the sediment to prevent S(2-) release into the overlying seawater. In Phase II, NO3(-) was injected into the sediment as an electron acceptor to facilitate the denitrification process. After 20 weeks of treatment, the sequential integration of the sulfate reduction and denitrification processes led to effective biodegradation of total petroleum hydrocarbons (TPH), in which about 72% of TPH was removed. In Phase I, the release of S(2-) was effectively controlled by the addition of akaganeite. The oxidation of S(2-) by Fe(3+) and the precipitation of S(2-) by Fe(2+) were the main mechanisms for S(2-) removal. In Phase II, the injection of NO3(-) completely inhibited the sulfate reduction process. Most of residual AVS and S(0) were removed within 4 weeks after NO3(-) injection. The 16S rRNA clone library-based analysis revealed a distinct shift of bacterial community structure in the sediment over different treatment phases. The clones affiliated with Desulfobacterales and Desulfuromonadales were the most abundant in Phase I, while the clones related to Thioalkalivibrio sulfidophilus, Thiohalomonas nitratireducens and Sulfurimonas denitrificans predominated in Phase II.

  1. Variation of ADM1 by using temperature-phased anaerobic digestion (TPAD) operation.

    Science.gov (United States)

    Lee, Myung-Yeol; Suh, Chang-Won; Ahn, Yong-Tae; Shin, Hang-Sik

    2009-06-01

    The objective of the study was to examine the application of the Anaerobic Digestion Model No. 1 (ADM1) developed by the IWA task group for mathematical modelling of anaerobic process. Lab-scale temperature-phased anaerobic digestion (TPAD) process were operated continuously, and were fed with co-substrate composed of dog food and flour. The model platform implemented in the simulation was a derivative of the ADM1. Sensitivity analysis showed that k(m.process) (maximum specific uptake rate) and K(S.process) (half saturation value) had high sensitivities to model components. Important parameters including maximum uptake rate for propionate utilisers (k(m.pro)) and half saturation constant for acetate utilisers (K(S.ac)) in the thermophilic digester and maximum uptake rate for acetate utilisers (k(m.ac)) in the mesophilic digester were estimated using iterative methods, which optimized the parameters with experimental results. Simulation with estimated parameters showed good agreement with experimental results in the case of methane production, uptake of acetate, soluble chemical oxygen demand (SCOD) and total chemical oxygen demand (TCOD). Under these conditions, the model predicted reasonably well the dynamic behavior of the TPAD process for verifying the model.

  2. Biohydrogen production by co-fermentation of crude glycerol and apple pomace hydrolysate using co-culture of Enterobacter aerogenes and Clostridium butyricum.

    Science.gov (United States)

    Pachapur, Vinayak Laxman; Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Le Bihan, Yann; Buelna, Gerardo; Verma, Mausam

    2015-10-01

    Co-substrate utilization of various wastes with complementary characteristics can provide a complete medium for higher hydrogen production. This study evaluated potential of apple pomace hydrolysate (APH) co-fermented with crude glycerol (CG) for increased H2 production and decreased by-products formation. The central composite design (CCD) along with response surface methodology (RSM) was used as tool for optimization and 15 g/L of CG, 5 g/L of APH and 15% (v/v) inoculum were found to be optimum to produce as high as 26.07 ± 1.57 mmol H2/L of medium. The p-value of 0.0017 indicated that APH at lower concentration had a significant effect on H2 production. By using CG as sole carbon source, reductive pathway of glycerol metabolism was favored with 19.46 mmol H2/L. However, with APH, oxidative pathway was favored with higher H2 production (26.07 ± 1.57 mmol/L) and decrease in reduced by-products (1,3-propanediol and ethanol) formation. APH inclusion enhanced H2 production, and decreased substrate inhibition.

  3. A rapid method for assaying thiaminase I activity in diverse biological samples.

    Directory of Open Access Journals (Sweden)

    Clifford E Kraft

    Full Text Available Vitamin B1 (thiamine deficiencies can lead to neurological disorders, reproductive failure and death in wild and domestic animal populations. In some cases, disease is brought about by the consumption of foods high in thiaminase I activity. Levels of thiaminase activity in these foods are highly variable and the factors leading to production of this enzyme are poorly understood. Here we describe improvements in a spectrophotometric thiaminase I activity assay that measures the disappearance of 4-nitrothiophenol, a favored nucleophile co-substrate that replaces the thiazole portion of thiamine during the inactivation of thiamine by the enzyme. Scalable sample processing protocols and a 96-well microtiter plate format are presented that allow the rapid evaluation of multiple, replicated samples in the course of only a few hours. Observed levels of activity in bacterial culture supernatant, fish, ferns and molluscs using this colorimetric assay were similar to previously published reports that employed a radiometric method. Organisms devoid of thiaminase I, based upon previous work, showed no activity with this assay. In addition, activity was found in a variety of fishes and one fern species from which this enzyme had not previously been reported. Overall, we demonstrate the suitability of this technique for measuring thiaminase I activity within small amounts of tissue and environmental samples with replication levels that were heretofore prohibitive. The assay provides a considerable improvement in the ability to examine and understand the properties of an enzyme that has a substantial influence on organism and ecosystem health.

  4. Biological nutrient transformation during composting of pig manure and paper waste.

    Science.gov (United States)

    Wong, Jonathan W C; Karthikeyan, Obulisamy P; Selvam, Ammaiyappan

    2017-03-01

    Composting of pig manure is a challenging task that requires appropriate co-substrate and bulking agent to provide optimum composting conditions and reduce nitrogen loss. In this study, paper waste is co-composted with pig manure as well as wood chips as the bulking agents. These raw materials were mixed at three different ratios of paper: pig manure: wood chips = 1:1:0 (pile 1), 3:2:1 (pile 2) and 3:1:1(pile 3), respectively. Each composting pile was about 11 m(3) in size equipped with negative-pressure forced aeration. The temperature of all the three piles ranged between 43 and 76°C and therefore produced pathogen-free compost. The overall total carbon reduction of 39%, 36% and 36% were achieved from pile 1, 2 and 3, respectively. The [Formula: see text] increased with the composting period, indicating the transformation of ammoniacal-N into nitrate by nitrification activity. However, all three piles showed significant variations in soluble [Formula: see text] at different stages of composting, which could be due to the microbial assimilation and mineralization. The results revealed that the co-composting of pig manure, paper along with wood chips was optimum under the mixing ratio of 3:2:1 (pile 2).

  5. Buffer-free production of gamma-aminobutyric acid using an engineered glutamate decarboxylase from Escherichia coli.

    Science.gov (United States)

    Kang, Taek Jin; Ho, Ngoc Anh Thu; Pack, Seung Pil

    2013-08-15

    Escherichia coli glutamate decarboxylase (GAD) converts glutamate into γ-aminobutyric acid (GABA) through decarboxylation using proton as a co-substrate. Since GAD is active only at acidic conditions even though pH increases as the reaction proceeds, the conventional practice of using this enzyme involved the use of relatively high concentration of buffers, which might complicate the downstream purification steps. Here we show by simulation and experiments that the free acid substrate, glutamic acid, rather than its monosodium salt can act as a substrate and buffer at the same time. This yielded the buffer- and salt-free synthesis of GABA conveniently in a batch mode. Furthermore, we engineered GAD to hyper active ones by extending or reducing the length of the enzyme by just one residue at its C-terminus. Through the buffer-free reaction with engineered GAD, we could synthesize 1M GABA in 3h, which can be translated into a space-time yield of 34.3g/L/h. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. The fasted/fed mouse metabolic acetylome: N6-acetylation differences suggest acetylation coordinates organ-specific fuel switching.

    Science.gov (United States)

    Yang, Li; Vaitheesvaran, Bhavapriya; Hartil, Kirsten; Robinson, Alan J; Hoopmann, Michael R; Eng, Jimmy K; Kurland, Irwin J; Bruce, James E

    2011-09-02

    The elucidation of extra-nuclear lysine acetylation has been of growing interest, as the cosubstrate for acetylation, acetyl CoA, is at a key metabolic intersection. Our hypothesis was that mitochondrial and cytoplasmic protein acetylation may be part of a fasted/re-fed feedback control system for the regulation of the metabolic network in fuel switching, where acetyl CoA would be provided by fatty acid oxidation, or glycolysis, respectively. To test this, we characterized the mitochondrial and cytoplasmic acetylome in various organs that have a high metabolic rate relative to their mass, and/or switch fuels, under fasted and re-fed conditions (brain, kidney, liver, skeletal muscle, heart muscle, white and brown adipose tissues). Using immunoprecipitation, coupled with LC-MS/MS label free quantification, we show there is a dramatic variation in global quantitative profiles of acetylated proteins from different organs. In total, 733 acetylated peptides from 337 proteins were identified and quantified, out of which 31 acetylated peptides from the metabolic proteins that may play organ-specific roles were analyzed in detail. Results suggest that fasted/re-fed acetylation changes coordinated by organ-specific (de)acetylases in insulin-sensitive versus -insensitive organs may underlie fuel use and switching. Characterization of the tissue-specific acetylome should increase understanding of metabolic conditions wherein normal fuel switching is disrupted, such as in Type II diabetes.

  7. Redox Enzymes of Red Beetroot Vacuoles (Beta vulgaris L.

    Directory of Open Access Journals (Sweden)

    E.V. Pradedova

    2014-12-01

    Full Text Available Years of research have shown that some of the redox elements (enzymes, coenzymes, and co-substrate are isolated from each other kinetic and spatial manner (compartmentalization in the eukaryotic cells. The redox elements forming the "highly" and "widely" specialized redox system are found in all cell structures: mitochondria, plastids, peroxisomes, apoplast, nucleus etc. In recent years the active involvement of the central vacuole in the maintenance of the plant cell redox homeostasis is discussed, actually the information about the vacuolar redox system is very small. The high-priority redox processes and "redox-specialization" of the vacuolar compartment are not known. We have begun a study of red beet-root vacuole redox systems (Beta vulgaris L. and have identified redox enzymes such as: phenol peroxidase (EC 1.11.1.7, superoxide dismutase (EC 1.15.1.1 and glutathione reductase (EC 1.8.1.7. This paper presents some of the characteristics of these enzymes and considers the probable ways of their functioning in vacuolar redox chains.

  8. Enhanced removal of PAHs by Peniophora incarnata and ascertainment of its novel ligninolytic enzyme genes.

    Science.gov (United States)

    Lee, Hwanhwi; Jang, Yeongseon; Lee, Young Min; Lee, Hanbyul; Kim, Gyu-Hyeok; Kim, Jae-Jin

    2015-12-01

    The hazardous effects of the PAHs should be managed by removal using white rot fungal ligninolytic enzymes. The white rot fungus Peniophora incarnataKUC8836 was stimulated to produce ligninolytic enzymes in a liquid medium by the addition of four substances: 0.5 g L(-1) Tween 80, 70 mg L(-1) CuSO4·5H2O, 10 mg L(-1) MnSO4·H2O, and 0.3 g L(-1) veratryl alcohol. The experiments were carried out in two different media: basal salt and 2% malt extract (ME) liquid medium. Under the experimental conditions, both laccase and manganese-dependent peroxidase (MnP) demonstrated with the highest activities in 2% ME liquid medium following the addition of Tween 80. The biodegradation of anthracene and pyrene was significantly enhanced by the induced ligninolytic enzymes when Tween 80 was added. Tween 80 is a viable co-substrate for P. incarnata, as it enhances the ability of P. incarnata to manage effective biodegradation of PAHs. Most of all, the novel laccase and MnP genes ascertained in this study, showed that the genes were involved in the production of ligninolytic enzymes from P. incarnataKUC8836.

  9. Sulfate addition as an effective method to improve methane fermentation performance and propionate degradation in thermophilic anaerobic co-digestion of coffee grounds, milk and waste activated sludge with AnMBR.

    Science.gov (United States)

    Li, Qian; Li, Yu-You; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki

    2015-06-01

    This study was conducted to investigate the effects of sulfate on propionate degradation and higher organic loading rate (OLR) achievement in a thermophilic AnMBR for 373days using coffee grounds, milk and waste activated sludge (WAS) as the co-substrate. Without the addition of sulfate, the anaerobic system failed at an OLR of 14.6g-COD/L/d, with propionate accumulating to above 2.23g-COD/L, and recovery by an alkalinity supplement was not successful. After sulfate was added into substrates at a COD/SO4(2-) ratio of 200:1 to 350:1, biogas production increased proportionally with OLR increasing from 4.06 to 15.2g-COD/L/d. Propionic acid was maintained at less than 100mg-COD/L due to the effective conversion of propionic acid to methane after the sulfate supplement was added. The long-term stable performance of the AnMBR indicated that adding sulfate was beneficial for the degradation of propionate and achieving a higher OLR under the thermophilic condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Incorporation of whey permeate, a dairy effluent, in ethanol fermentation to provide a zero waste solution for the dairy industry.

    Science.gov (United States)

    Parashar, Archana; Jin, Yiqiong; Mason, Beth; Chae, Michael; Bressler, David C

    2016-03-01

    This study proposes a novel alternative for utilization of whey permeate, a by-product stream from the dairy industry, in wheat fermentation for ethanol production using Saccharomyces cerevisiae. Whey permeates were hydrolyzed using enzymes to release fermentable sugars. Hydrolyzed whey permeates were integrated into wheat fermentation as a co-substrate or to partially replace process water. Cold starch hydrolysis-based simultaneous saccharification and fermentation was done as per the current industrial protocol for commercial wheat-to-ethanol production. Ethanol production was not affected; ethanol yield efficiency did not change when up to 10% of process water was replaced. Lactic acid bacteria in whey permeate did not negatively affect the co-fermentation or reduce ethanol yield. Whey permeate could be effectively stored for up to 4 wk at 4 °C with little change in lactose and lactic acid content. Considering the global abundance and nutrient value of whey permeate, the proposed strategy could improve economics of the dairy and biofuel sectors, and reduce environmental pollution. Furthermore, our research may be applied to fermentation strategies designed to produce value-added products other than ethanol. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Non-enzymatic chemistry enables 2-hydroxyglutarate-mediated activation of 2-oxoglutarate oxygenases

    Science.gov (United States)

    Tarhonskaya, Hanna; Rydzik, Anna M.; Leung, Ivanhoe K. H.; Loik, Nikita D.; Chan, Mun Chiang; Kawamura, Akane; McCullagh, James S. O.; Claridge, Timothy D. W.; Flashman, Emily; Schofield, Christopher J.

    2014-01-01

    Accumulation of (R)-2-hydroxyglutarate in cells results from mutations to isocitrate dehydrogenase that correlate with cancer. A recent study reports that (R)-, but not (S)-2-hydroxyglutarate, acts as a co-substrate for the hypoxia-inducible factor prolyl hydroxylases via enzyme-catalysed oxidation to 2-oxoglutarate. Here we investigate the mechanism of 2-hydroxyglutarate-enabled activation of 2-oxoglutarate oxygenases, including prolyl hydroxylase domain 2, the most important human prolyl hydroxylase isoform. We observe that 2-hydroxyglutarate-enabled catalysis by prolyl hydroxylase domain 2 is not enantiomer-specific and is stimulated by ferrous/ferric ion and reducing agents including L-ascorbate. The results reveal that 2-hydroxyglutarate is oxidized to 2-oxoglutarate non-enzymatically, likely via iron-mediated Fenton-chemistry, at levels supporting in vitro catalysis by 2-oxoglutarate oxygenases. Succinic semialdehyde and succinate are also identified as products of 2-hydroxyglutarate oxidation. Overall, the results rationalize the reported effects of 2-hydroxyglutarate on catalysis by prolyl hydroxylases in vitro and suggest that non-enzymatic 2-hydroxyglutarate oxidation may be of biological interest. PMID:24594748

  12. Schisandrin B-induced glutathione antioxidant response and cardioprotection are mediated by reactive oxidant species production in rat hearts.

    Science.gov (United States)

    Chen, Na; Ko, Ming

    2010-01-01

    To investigate the involvement of reactive oxidant species (ROS), presumably arising from cytochrome P-450 (CYP)-catalyzed metabolism of schisandrin B (Sch B), in triggering glutathione antioxidant response, Sch B induced reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent and CYP-catalyzed reaction and associated ROS production were examined in rat heart microsomes. Sch B analogs were also studied for comparison. Using rat heart microsomes as a source of CYP, Sch B and schisandrin C (Sch C), but not schisandrin A and dimethyl diphenyl bicarboxylate (an intermediate compound derived from the synthesis of Sch C), were found to serve as co-substrate for the CYP-catalyzed NADPH oxidation reaction, with concomitant production of ROS. The stimulation of CYP-catalyzed NADPH oxidation reaction and/or ROS production by Sch B or Sch C correlated with the increase in mitochondrial reduced glutathione level and protection against ischemia/reperfusion (I/R) injury in rat hearts. The involvement of ROS in Sch B-induced cardioprotection was further confirmed by the suppressive effect produced by N-acetylcysteine or alpha-tocopherol pretreatment. Taken together, these results suggest that Sch B-induced glutathione antioxidant response and cardioprotection may be mediated by ROS arising from CYP-catalyzed reaction.

  13. Novel assay for simultaneous measurement of pyridine mononucleotides synthesizing activities allows dissection of the NAD(+) biosynthetic machinery in mammalian cells.

    Science.gov (United States)

    Zamporlini, Federica; Ruggieri, Silverio; Mazzola, Francesca; Amici, Adolfo; Orsomando, Giuseppe; Raffaelli, Nadia

    2014-11-01

    The redox coenzyme NAD(+) is also a rate-limiting co-substrate for several enzymes that consume the molecule, thus rendering its continuous re-synthesis indispensable. NAD(+) biosynthesis has emerged as a therapeutic target due to the relevance of NAD(+) -consuming reactions in complex intracellular signaling networks whose alteration leads to many neurologic and metabolic disorders. Distinct metabolic routes, starting from various precursors, are known to support NAD(+) biosynthesis with tissue/cell-specific efficiencies, probably reflecting differential expression of the corresponding rate-limiting enzymes, i.e. nicotinamide phosphoribosyltransferase, quinolinate phosphoribosyltransferase, nicotinate phosphoribosyltransferase and nicotinamide riboside kinase. Understanding the contribution of these enzymes to NAD(+) levels depending on the tissue/cell type and metabolic status is necessary for the rational design of therapeutic strategies aimed at modulating NAD(+) availability. Here we report a simple, fast and sensitive coupled fluorometric assay that enables simultaneous determination of the four activities in whole-cell extracts and biological fluids. Its application to extracts from various mouse tissues, human cell lines and plasma yielded for the first time an overall picture of the tissue/cell-specific distribution of the activities of the various enzymes. The screening enabled us to gather novel findings, including (a) the presence of quinolinate phosphoribosyltransferase and nicotinamide riboside kinase in all examined tissues/cell lines, indicating that quinolinate and nicotinamide riboside are relevant NAD(+) precursors, and (b) the unexpected occurrence of nicotinate phosphoribosyltransferase in human plasma.

  14. The NAD(+) precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesity.

    Science.gov (United States)

    Cantó, Carles; Houtkooper, Riekelt H; Pirinen, Eija; Youn, Dou Y; Oosterveer, Maaike H; Cen, Yana; Fernandez-Marcos, Pablo J; Yamamoto, Hiroyasu; Andreux, Pénélope A; Cettour-Rose, Philippe; Gademann, Karl; Rinsch, Chris; Schoonjans, Kristina; Sauve, Anthony A; Auwerx, Johan

    2012-06-06

    As NAD(+) is a rate-limiting cosubstrate for the sirtuin enzymes, its modulation is emerging as a valuable tool to regulate sirtuin function and, consequently, oxidative metabolism. In line with this premise, decreased activity of PARP-1 or CD38-both NAD(+) consumers-increases NAD(+) bioavailability, resulting in SIRT1 activation and protection against metabolic disease. Here we evaluated whether similar effects could be achieved by increasing the supply of nicotinamide riboside (NR), a recently described natural NAD(+) precursor with the ability to increase NAD(+) levels, Sir2-dependent gene silencing, and replicative life span in yeast. We show that NR supplementation in mammalian cells and mouse tissues increases NAD(+) levels and activates SIRT1 and SIRT3, culminating in enhanced oxidative metabolism and protection against high-fat diet-induced metabolic abnormalities. Consequently, our results indicate that the natural vitamin NR could be used as a nutritional supplement to ameliorate metabolic and age-related disorders characterized by defective mitochondrial function.

  15. Optimization of the heterologous production of a Rhizopus oryzae lipase in Pichia pastoris system using mixed substrates on controlled fed-batch bioprocess.

    Science.gov (United States)

    Arnau, Carolina; Ramon, Ramon; Casas, Carles; Valero, Francisco

    2010-05-05

    In this work a systematic study of the influence of methanol set-point and sorbitol feeding rate in fed-batch operation with a Pichia pastoris Mut(s) strain producing Rhizopus oryzae lipase is presented. Different experiments were made at a constant methanol set-point of 0.5, 2 and 4gl(-1), controlled by a predictive algorithm at two different sorbitol feeding rates to assure a constant specific growth rate of 0.01 and 0.02h(-1), by means of a pre-programmed exponential feeding rate strategy. Lipolytic activity, yields, productivity and specific productivity, but also specific growth, consumption and production rates were analyzed showing that the best values were reached when the methanol set-point was 2gl(-1) with a low influence of the constant specific growth rate tested. The sorbitol addition as a co-substrate during the induction phase avoids the severe decrease of the specific production rate obtained when methanol was used as a sole carbon source and it permits to achieve higher ROL production.

  16. Epoxy Coenzyme A Thioester pathways for degradation of aromatic compounds.

    Science.gov (United States)

    Ismail, Wael; Gescher, Johannes

    2012-08-01

    Aromatic compounds (biogenic and anthropogenic) are abundant in the biosphere. Some of them are well-known environmental pollutants. Although the aromatic nucleus is relatively recalcitrant, microorganisms have developed various catabolic routes that enable complete biodegradation of aromatic compounds. The adopted degradation pathways depend on the availability of oxygen. Under oxic conditions, microorganisms utilize oxygen as a cosubstrate to activate and cleave the aromatic ring. In contrast, under anoxic conditions, the aromatic compounds are transformed to coenzyme A (CoA) thioesters followed by energy-consuming reduction of the ring. Eventually, the dearomatized ring is opened via a hydrolytic mechanism. Recently, novel catabolic pathways for the aerobic degradation of aromatic compounds were elucidated that differ significantly from the established catabolic routes. The new pathways were investigated in detail for the aerobic bacterial degradation of benzoate and phenylacetate. In both cases, the pathway is initiated by transforming the substrate to a CoA thioester and all the intermediates are bound by CoA. The subsequent reactions involve epoxidation of the aromatic ring followed by hydrolytic ring cleavage. Here we discuss the novel pathways, with a particular focus on their unique features and occurrence as well as ecological significance.

  17. Biofiltration of methyl tert-butyl ether vapors by cometabolism with pentane: modeling and experimental approach.

    Science.gov (United States)

    Dupasquier, David; Revah, Sergio; Auria, Richard

    2002-01-15

    Degradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with pentane using a culture of pentane-oxidizing bacteria (Pseudomonas aeruginosa) was studied in a 2.4-L biofilter packed with vermiculite, an inert mineral support. Experimental pentane elimination capacity (EC) of approximately 12 g m(-3) h(-1) was obtained for an empty bed residence time (EBRT) of 1.1 h and inlet concentration of 18.6 g m(-3). For these experimental conditions, EC of MTBE between 0.3 and 1.8 g m(-3) h(-1) were measured with inlet MTBE concentration ranging from 1.1 to 12.3 g m(-3). The process was modeled with general mass balance equations that consider a kinetic model describing cross-competitive inhibition between MTBE (cosubstrate) and pentane (substrate). The experimental data of pentane and MTBE removal efficiencies were compared to the theoretical predictions of the model. The predicted pentane and MTBE concentration profiles agreed with the experimental data for steady-state operation. Inhibition by MTBE of the pentane EC was demonstrated. Increasing the inlet pentane concentration improved the EC of MTBE but did not significantly change the EC of pentane. MTBE degradation rates obtained in this study were much lower than those using consortia or pure strains that can mineralize MTBE. Nevertheless, the system can be improved by increasing the active biomass.

  18. Naphthalene degradation by bacterial consortium (DV-AL) developed from Alang-Sosiya ship breaking yard, Gujarat, India.

    Science.gov (United States)

    Patel, Vilas; Jain, Siddharth; Madamwar, Datta

    2012-03-01

    Naphthalene degrading bacterial consortium (DV-AL) was developed by enrichment culture technique from sediment collected from the Alang-Sosiya ship breaking yard, Gujarat, India. The 16S rRNA gene based molecular analyzes revealed that the bacterial consortium (DV-AL) consisted of four strains namely, Achromobacter sp. BAB239, Pseudomonas sp. DV-AL2, Enterobacter sp. BAB240 and Pseudomonas sp. BAB241. Consortium DV-AL was able to degrade 1000 ppm of naphthalene in Bushnell Haas medium (BHM) containing peptone (0.1%) as co-substrate with an initial pH of 8.0 at 37°C under shaking conditions (150 rpm) within 24h. Maximum growth rate and naphthalene degradation rate were found to be 0.0389 h(-1) and 80 mg h(-1), respectively. Consortium DV-AL was able to utilize other aromatic and aliphatic hydrocarbons such as benzene, phenol, carbazole, petroleum oil, diesel fuel, and phenanthrene and 2-methyl naphthalene as sole carbon source. Consortium DV-AL was also efficient to degrade naphthalene in the presence of other pollutants such as petroleum hydrocarbons and heavy metals.

  19. Process Evaluation Tools for Enzymatic Cascades Welcome Message

    DEFF Research Database (Denmark)

    Abu, Rohana

    Biocatalysis is attracting significant attention from both academic and industrial scientists due to the excellent capability of enzyme to catalyse selective reactions. Recently, much interest has been shown in the application of enzymatic cascades as a useful tool in organic synthesis to synthes......Biocatalysis is attracting significant attention from both academic and industrial scientists due to the excellent capability of enzyme to catalyse selective reactions. Recently, much interest has been shown in the application of enzymatic cascades as a useful tool in organic synthesis...... the atom economy. The scheme consists of two primary enzymes (alcohol dehydrogenase and ω-transaminase) that are directly involved in the main synthesis. Alanine dehydrogenase was introduced as a secondary enzyme to regenerate the co-factor NAD+ and co-substrate alanine in situ as well as to shift...... the equilibrium positions in the main syntheses. In principle, this strategy could successfully achieve high conversion, using ammonia as the sole reagent used in excess to drive the conversion. The findings herein indicate that quantitatively the possibilities for improving the conversion of thermodynamically...

  20. Direct Bioconversion of Oil Palm Empty Fruit Bunches for Bioethanol Production By Solid State Bioconversion

    Directory of Open Access Journals (Sweden)

    Nassereldeen Ahmed Kabbashi

    2010-09-01

    Full Text Available The bioethanol production was conducted by utilizing agriculture waste, palm oil empty fruit bunches (EFB with the aid of T. harzianum and yeast, Saccharomyces cerevisiae using solid state bioconversion method. The compatibility of various fungal strains was done as to develop the direct bioconversion process of compatible mixed culture. Analyzes such ethanol estimation, reducing sugar and glucosamine as growth indicator were conducted in order to select the best experimented run for optimization. The optimization of process conditions, by using central composite design (CCD was carried out. Optimization of process condition was done with varied level of moisture content, pH, inoculum size, concentration of co-substrate (wheat flour and mineral solutions. Statistical analysis showed that the optimum process condition for moisture content was 50% (v/w, pH of 4, inoculum size of 10% (v/v, concentration of wheat flour of 1% (v/v and mineral solutions 1%(v/v. In this study, the application levels of the methods of environmental management in regards to the maximum production were determined. The final optimization with the developed process conditions indicated that the maximum production was increased from 14.315 (v/v to 34.785(v/v.

  1. Crystal structures of cyclohexanone monooxygenase reveal complex domain movements and a sliding cofactor.

    Science.gov (United States)

    Mirza, I Ahmad; Yachnin, Brahm J; Wang, Shaozhao; Grosse, Stephan; Bergeron, Hélène; Imura, Akihiro; Iwaki, Hiroaki; Hasegawa, Yoshie; Lau, Peter C K; Berghuis, Albert M

    2009-07-01

    Cyclohexanone monooxygenase (CHMO) is a flavoprotein that carries out the archetypical Baeyer-Villiger oxidation of a variety of cyclic ketones into lactones. Using NADPH and O(2) as cosubstrates, the enzyme inserts one atom of oxygen into the substrate in a complex catalytic mechanism that involves the formation of a flavin-peroxide and Criegee intermediate. We present here the atomic structures of CHMO from an environmental Rhodococcus strain bound with FAD and NADP(+) in two distinct states, to resolutions of 2.3 and 2.2 A. The two conformations reveal domain shifts around multiple linkers and loop movements, involving conserved arginine 329 and tryptophan 492, which effect a translation of the nicotinamide resulting in a sliding cofactor. Consequently, the cofactor is ideally situated and subsequently repositioned during the catalytic cycle to first reduce the flavin and later stabilize formation of the Criegee intermediate. Concurrent movements of a loop adjacent to the active site demonstrate how this protein can effect large changes in the size and shape of the substrate binding pocket to accommodate a diverse range of substrates. Finally, the previously identified BVMO signature sequence is highlighted for its role in coordinating domain movements. Taken together, these structures provide mechanistic insights into CHMO-catalyzed Baeyer-Villiger oxidation.

  2. Application of (13)C-stable isotope probing to identify RDX-degrading microorganisms in groundwater.

    Science.gov (United States)

    Cho, Kun-Ching; Lee, Do Gyun; Roh, Hyungkeun; Fuller, Mark E; Hatzinger, Paul B; Chu, Kung-Hui

    2013-07-01

    We employed stable isotope probing (SIP) with (13)C-labeled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to identify active microorganisms responsible for RDX biodegradation in groundwater microcosms. Sixteen different 16S rRNA gene sequences were derived from microcosms receiving (13)C-labeled RDX, suggesting the presence of microorganisms able to incorporate carbon from RDX or its breakdown products. The clones, residing in Bacteroidia, Clostridia, α-, β- and δ-Proteobacteria, and Spirochaetes, were different from previously described RDX degraders. A parallel set of microcosms was amended with cheese whey and RDX to evaluate the influence of this co-substrate on the RDX-degrading microbial community. Cheese whey stimulated RDX biotransformation, altered the types of RDX-degrading bacteria, and decreased microbial community diversity. Results of this study suggest that RDX-degrading microorganisms in groundwater are more phylogenetically diverse than what has been inferred from studies with RDX-degrading isolates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Putrescine N-methyltransferase--the start for alkaloids.

    Science.gov (United States)

    Biastoff, Stefan; Brandt, Wolfgang; Dräger, Birgit

    2009-01-01

    Putrescine N-methyltransferase (PMT) catalyses S-adenosylmethionine (SAM) dependent methylation of the diamine putrescine. The product N-methylputrescine is the first specific metabolite on the route to nicotine, tropane, and nortropane alkaloids. PMT cDNA sequences were cloned from tobacco species and other Solanaceae, also from nortropane-forming Convolvulaceae and enzyme proteins were synthesised in Escherichia coli. PMT activity was measured by HPLC separation of polyamine derivatives and by an enzyme-coupled colorimetric assay using S-adenosylhomocysteine. PMT cDNA sequences resemble those of plant spermidine synthases (putrescine aminopropyltransferases) and display little similarity to other plant methyltransferases. PMT is likely to have evolved from the ubiquitous enzyme spermidine synthase. PMT and spermidine synthase proteins share the same overall protein structure; they bind the same substrate putrescine and similar co-substrates, SAM and decarboxylated S-adenosylmethionine. The active sites of both proteins, however, were shaped differentially in the course of evolution. Phylogenetic analysis of both enzyme groups from plants revealed a deep bifurcation and confirmed an early descent of PMT from spermidine synthase in the course of angiosperm development.

  4. Towards Controlling the Glycoform: A Model Framework Linking Extracellular Metabolites to Antibody Glycosylation

    Directory of Open Access Journals (Sweden)

    Philip M. Jedrzejewski

    2014-03-01

    Full Text Available Glycoproteins represent the largest group of the growing number of biologically-derived medicines. The associated glycan structures and their distribution are known to have a large impact on pharmacokinetics. A modelling framework was developed to provide a link from the extracellular environment and its effect on intracellular metabolites to the distribution of glycans on the constant region of an antibody product. The main focus of this work is the mechanistic in silico reconstruction of the nucleotide sugar donor (NSD metabolic network by means of 34 species mass balances and the saturation kinetics rates of the 60 metabolic reactions involved. NSDs are the co-substrates of the glycosylation process in the Golgi apparatus and their simulated dynamic intracellular concentration profiles were linked to an existing model describing the distribution of N-linked glycan structures of the antibody constant region. The modelling framework also describes the growth dynamics of the cell population by means of modified Monod kinetics. Simulation results match well to experimental data from a murine hybridoma cell line. The result is a modelling platform which is able to describe the product glycoform based on extracellular conditions. It represents a first step towards the in silico prediction of the glycoform of a biotherapeutic and provides a platform for the optimisation of bioprocess conditions with respect to product quality.

  5. Biodecolorization of Reactive Yellow-2 by Serratia sp. RN34 Isolated from Textile Wastewater.

    Science.gov (United States)

    Najme, Rabia; Hussain, Sabir; Maqbool, Zahid; Imran, Muhammad; Mahmood, Faisal; Manzoor, Hamid; Yasmeen, Tahira; Shehzad, Tanvir

    2015-12-01

    Remediation of colored textile wastewaters is a matter of interest. In this study, 49 bacteria were isolated from the textile wastewater and tested for their ability to decolorize reactive yellow-2 (RY2) dye. The most efficient isolate, RN34, was identified through amplification, sequencing, and phylogenetic analysis of its 16S rDNA and was designated as Serratia sp. RN34. This bacterium was also found capable of decolorizing other related reactive azo-dyes, including reactive black-5, reactive red-120, and reactive orange-16 but at varying rates. The optimum pH for decolorization of RY2 by the strain RN34 was 7.5 using yeast extract as cosubstrate under static incubation at 30 °C. The strain RN34 also showed potential to decolorize RY2 in the presence of considerable amounts of hexavalent chromium and sodium chloride. A phytotoxicity study demonstrated relatively reduced toxicity of RY2 decolorized products on Vigna radiata plant as compared to the uninoculated RY2 solution.

  6. Decolourisation of Acid Orange 7 recalcitrant auto-oxidation coloured by-products using an acclimatised mixed bacterial culture.

    Science.gov (United States)

    Bay, Hui Han; Lim, Chi Kim; Kee, Thuan Chien; Ware, Ismail; Chan, Giek Far; Shahir, Shafinaz; Ibrahim, Zaharah

    2014-03-01

    This study focuses on the biodegradation of recalcitrant, coloured compounds resulting from auto-oxidation of Acid Orange 7 (AO7) in a sequential facultative anaerobic-aerobic treatment system. A novel mixed bacterial culture, BAC-ZS, consisting of Brevibacillus panacihumi strain ZB1, Lysinibacillus fusiformis strain ZB2, and Enterococcus faecalis strain ZL bacteria were isolated from environmental samples. The acclimatisation of the mixed culture was carried out in an AO7 decolourised solution. The acclimatised mixed culture showed 98 % decolourisation within 2 h of facultative anaerobic treatment using yeast extract and glucose as co-substrate. Subsequent aerobic post treatment caused auto-oxidation reaction forming dark coloured compounds that reduced the percentage decolourisation to 73 %. Interestingly, further agitations of the mixed culture in the solution over a period of 48 h significantly decolourise the coloured compounds and increased the decolourisation percentage to 90 %. Analyses of the degradation compounds using UV-visible spectrophotometer, Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) showed complete degradation of recalcitrant AO7 by the novel BAC-ZS. Phytotoxicity tests using Cucumis sativus confirmed the dye solution after post aerobic treatment were less toxic compared to the parent dye. The quantitative real-time PCR revealed that E. faecalis strain ZL was the dominant strain in the acclimatised mix culture.

  7. Accelerated azo dye degradation and concurrent hydrogen production in the single-chamber photocatalytic microbial electrolysis cell.

    Science.gov (United States)

    Hou, Yanping; Zhang, Renduo; Yu, Zebin; Huang, Lirong; Liu, Yuxin; Zhou, Zili

    2017-01-01

    The single-chamber microbial electrolysis cell constructed with a TiO2-coated photocathode, termed photocatalytic microbial electrolysis cell (PMEC), was developed to accelerate methyl orange (MO) degradation and concurrent hydrogen (H2) recovery under UV irradiation. Results showed that faster MO decolorization rates were achieved from the PMEC compared with those without UV irradiation or with open circuit. With increase of MO concentrations (acetate as co-substrate) from 50 to 300mg/L at an applied voltage of 0.8V, decolorization efficiencies decreased from 98% to 76% within 12h, and cyclic H2 production declined from 113 to 68mL. As the possible mechanism of MO degradation, bioelectrochemical reduction, co-metabolism reduction, and photocatalysis were involved; and degradation intermediates (mainly sulfanilic acid and N,N-dimethylaniline) were further degraded by OH generated from photocatalysis. This makes MO mineralization be possible in the single-chamber PMEC. Hence, the PMEC is a promising system for dyeing wastewater treatment and simultaneous H2 production.

  8. [Cooperation of mixed culturing bacteria in the hydrogen production by fermentation].

    Science.gov (United States)

    Lin, Ming; Ren, Nanqi; Wang, Aijie; Wang, Xiangjing

    2003-03-01

    In order to discuss the cooperation of H2-producing fermentation bacteria (HPFB) in mixed culture, a batch test fed with glucose and complex organic substance (starch, beef, PEP and peptone) respectively, was conducted to investigate the effects of mixed culture on H2-producing ability. For the systemic and accurate analysis, three kinds of the mixed culture were use to this batch test. It included that the mixed culture with five strains of HPFB (B49, H1, LM12, LM11 and B51), B49 and three stains of non-HPFB (L10, Bacteroide 3-2, Sporobacterl), and B49 and hydrogen producing sludge. The results showed that the cooperation of mixed culturing bacteria was conditional on the substrates. When fed with glucose, which were easily utilized by HPB, the H2-producing ability of HPB was restrained because of the competition on the co-substrate between HPB and other fermentation bacteria, and it was quite difficult for the cooperation of mixed culturing bacteria to be performed. When fed with complex organic substance, the H2-producing ability of HPB was enhanced via the cooperation of mixed culturing bacteria. Furthermore, a strategy was put forward, that is, different kind of HPB cultures could be adopted according to the difference of substrates.

  9. Production of L-phenylacetylcarbinol by free and immobilized yeast cells.

    Science.gov (United States)

    Tripathi, C K; Agarwal, S C; Bihari, V; Joshi, A K; Basu, S K

    1997-08-01

    Production of L-phenylacetylcarbinol (L-PAC) through biotransformation of benzaldehyde by free and immobilized cells of the yeast Saccharomyces cerevisiae has been attempted. L-PAC production was found to be maximum (0.4 microliter/ml) when anaerobically grown free cells were used as biocatalyst during aerobic biotransformation for two hours with magnetically stirred bioreactor. Growth under oxygen limited conditions led to accumulation of higher amount of pyruvate decarboxylase enzyme and co-substrate, pyruvate, resulting in higher L-PAC formation. L-PAC yield was low when biotransformations were carried out anaerobically either for aerobically or anaerobically grown free cells. Free cells were found to be more efficient biocatalyst for L-PAC production, as compared with the immobilized cells, with the investigated benzaldehyde concentration (0.3% v/v) and cell density (17.5% w/v). The study has explored and indicated the possibility of optimizing the yield of L-PAC by growing the yeast cells under oxygen limited condition for suitable aerobic mode of benzaldehyde biotransformation.

  10. Enhancement of Peroxidase Stability Against Oxidative Self-Inactivation by Co-immobilization with a Redox-Active Protein in Mesoporous Silicon and Silica Microparticles

    Science.gov (United States)

    Sahare, P.; Ayala, M.; Vazquez-Duhalt, R.; Pal, U.; Loni, A.; Canham, L. T.; Osorio, I.; Agarwal, V.

    2016-09-01

    The study of the stability enhancement of a peroxidase immobilized onto mesoporous silicon/silica microparticles is presented. Peroxidases tend to get inactivated in the presence of hydrogen peroxide, their essential co-substrate, following an auto-inactivation mechanism. In order to minimize this inactivation, a second protein was co-immobilized to act as an electron acceptor and thus increase the stability against self-oxidation of peroxidase. Two heme proteins were immobilized into the microparticles: a fungal commercial peroxidase and cytochrome c from equine heart. Two types of biocatalysts were prepared: one with only covalently immobilized peroxidase (one-protein system) and another based on covalent co-immobilization of peroxidase and cytochrome c (two-protein system), both immobilized by using carbodiimide chemistry. The amount of immobilized protein was estimated spectrophotometrically, and the characterization of the biocatalyst support matrix was performed using Brunauer-Emmett-Teller (BET), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared (FTIR) analyses. Stability studies show that co-immobilization with the two-protein system enhances the oxidative stability of peroxidase almost four times with respect to the one-protein system. Thermal stability analysis shows that the immobilization of peroxidase in derivatized porous silicon microparticles does not protect the protein from thermal denaturation, whereas biogenic silica microparticles confer significant thermal stabilization.

  11. The effect of dilution and L-malic acid addition on bio-hydrogen production with Rhodopseudomonas palustris from effluent of an acidogenic anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Azbar, Nuri; Cetinkaya Dokgoz, F.Tuba [Ege University, Faculty of Engineering, Bioengineering Department, 35100 Izmir (Turkey)

    2010-05-15

    In this study, H{sub 2} was produced from cheese whey wastewater in a two-stage biological process: i) first stage; thermophilic dark fermentation ii) second stage; the photo fermentation using Rhodopseudomonas palustris strain DSM 127 (R. palustris). The effect of both dilution and addition of L-malic acid on the hydrogen production was investigated. Among the dilution rates used, 1/5 dilution ratio was found to produce the best hydrogen production (349 ml H{sub 2}/g COD{sub fed}). On the other hand, It was seen that the mixing the effluent with L-malic acid at increasing ratios had further positive effect and improved the hydrogen production significantly. It was concluded that dilution of the feeding helps to reduce the nitrogen content and the volatile fatty acid content that might be otherwise harmful to the photo-heterotrophic organisms. Overall hydrogen production yield (for dark + photo fermentation) was found to vary 2 and 10 mol H{sub 2}/mol lactose. Second conclusion is that cheese whey effluent should be mixed with a co-substrate containing L-malic acid such as apple juice processing effluents before fed into the photo fermentation reactor. (author)

  12. A NADH-accepting imine reductase variant: Immobilization and cofactor regeneration by oxidative deamination.

    Science.gov (United States)

    Gand, Martin; Thöle, Christian; Müller, Hubertus; Brundiek, Henrike; Bashiri, Ghader; Höhne, Matthias

    2016-07-20

    Engineering cofactor specificity of enzymes is a promising approach that can expand the application of enzymes for biocatalytic production of industrially relevant chemicals. Until now, only NADPH-dependent imine reductases (IREDs) are known. This limits their applications to reactions employing whole cells as a cost-efficient cofactor regeneration system. For applications of IREDs as cell-free catalysts, (i) we created an IRED variant showing an improved activity for NADH. With rational design we were able to identify four residues in the (R)-selective IRED from Streptomyces GF3587 (IR-Sgf3587), which coordinate the 2'-phosphate moiety of the NADPH cofactor. From a set of 15 variants, the highest NADH activity was caused by the single amino acid exchange K40A resulting in a 3-fold increased acceptance of NADH. (ii) We showed its applicability using an immobilisate obtained either from purified enzyme or from lysate using the EziG(™) carriers. Applying the variant and NADH, we reached 88% conversion in a preparative scale biotransformation when employing 4% (w/v) 2-methylpyrroline. (iii) We demonstrated a one-enzyme cofactor regeneration approach using the achiral amine N-methyl-3-aminopentanone as a hydrogen donor co-substrate. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Microbial production of biovanillin

    Directory of Open Access Journals (Sweden)

    A. Converti

    2010-10-01

    Full Text Available This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.

  14. Potential of Penicillium Species in the Bioremediation Field

    Science.gov (United States)

    Leitão, Ana Lúcia

    2009-01-01

    The effects on the environment of pollution, particularly that caused by various industrial activities, have been responsible for the accelerated fluxes of organic and inorganic matter in the ecosphere. Xenobiotics such as phenol, phenolic compounds, polycyclic aromatic hydrocarbons (PAHs), and heavy metals, even at low concentrations, can be toxic to humans and other forms of life. Many of the remediation technologies currently being used for contaminated soil and water involve not only physical and chemical treatment, but also biological processes, where microbial activity is the responsible for pollutant removal and/or recovery. Fungi are present in aquatic sediments, terrestrial habitats and water surfaces and play a significant part in natural remediation of metal and aromatic compounds. Fungi also have advantages over bacteria since fungal hyphae can penetrate contaminated soil, reaching not only heavy metals but also xenobiotic compounds. Despite of the abundance of such fungi in wastes, penicillia in particular have received little attention in bioremediation and biodegradation studies. Additionally, several studies conducted with different strains of imperfecti fungi, Penicillium spp. have demonstrated their ability to degrade different xenobiotic compounds with low co-substrate requirements, and could be potentially interesting for the development of economically feasible processes for pollutant transformation. PMID:19440525

  15. Asymmetric Reduction of3,5-Bistrifluoromethyl Acetophenone with NADH Regeneration by Immobilized Cells of Saccharomyces rhodotorula in Aqueous-Organic Solvent Biphasic System%Asymmetric Reduction of 3,5-Bistrifluoromethyl Acetophenone with NADH Regeneration by Immobilized Cells of Saccharomyces rhodotorula in Aqueous-Organic Solvent Biphasic System

    Institute of Scientific and Technical Information of China (English)

    ZHANGFang; XUEYing; LILi; WANG Min

    2011-01-01

    Asymmetric reduction of 3,5-bistrifluoromethyl acetophenone to produce (S)-3,5-bistrifluoromethylphenyl ethanol was successfully carried out with sodium alginate immobilized Saccharomyces rhodotorula cells in an aqueous-organic solvent biphasic system.The possible influential factors were examined thoroughly according to their effects on conversion rate and e.e of the product.Organic solvents were rated by their biocompatibility and conversion potential.The immobilized cells [125 mg/mL in 20 mmol/L Tris-HCl buffer and 5%(φ) octane at pH 8] showed the best conversion with a substrate concentration of 1.42 g/L at 30C with glucose as co-substrate for cofactor regeneration.Sequential 8-batch process was carried out with immobilized cells with a slow decrease in conversion and e.e.The immobilized cells showed stable catalytic activity with 50% reserved activity and are superior especially in reusability in comparison with resting cells.

  16. Enhancement of biofuels production by means of co-pyrolysis of Posidonia oceanica (L.) and frying oil wastes: Experimental study and process modeling.

    Science.gov (United States)

    Zaafouri, Kaouther; Ben Hassen Trabelsi, Aida; Krichah, Samah; Ouerghi, Aymen; Aydi, Abdelkarim; Claumann, Carlos Alberto; André Wüst, Zibetti; Naoui, Silm; Bergaoui, Latifa; Hamdi, Moktar

    2016-05-01

    Energy recovery from lignocellulosic solid marine wastes, Posidonia oceanica wastes (POW) with slow pyrolysis responds to the growing trend of alternative energies as well as waste management. Physicochemical, thermogravimetric (TG/DTG) and spectroscopic (FTIR) characterizations of POW were performed. POW were first converted by pyrolysis at different temperatures (450°C, 500°C, 550°C and 600°C) using a fixed-bed reactor. The obtained products (bio-oil, syngas and bio char) were analyzed. Since the bio-oil yield obtained from POW pyrolysis is low (2wt.%), waste frying oil (WFO) was added as a co-substrate in order to improve of biofuels production. The co-pyrolysis gave a better yield of liquid organic fraction (37wt.%) as well as syngas (CH4,H2…) with a calorific value around 20MJ/kg. The stoichiometric models of both pyrolysis and co-pyrolysis reactions were performed according to the biomass formula: CαHβOγNδSε. The thermal kinetic decomposition of solids was validated through linearized Arrhenius model.

  17. Anaerobic treatment of olive mill wastewater and piggery effluents fermented with Candida tropicalis.

    Science.gov (United States)

    Martinez-Garcia, Gregorio; Johnson, Anbu Clemensis; Bachmann, Robert T; Williams, Ceri J; Burgoyne, Andrea; Edyvean, Robert G J

    2009-05-30

    Olive mill wastewater (OMW) contains high concentrations of phenolic compounds that are inhibitory to many microorganisms making it difficult to treat biologically prior to discharge in waterways. The total mono-cyclic phenol reduction in OMW in this study was carried out by aerobic pre-treatment using the yeast Candida tropicalis in a 18 L batch reactor at 30 degrees C for 12 days followed by anaerobic co-digestion. A COD removal of 62% and a reduction in the total mono-cyclic phenol content by 51% of the mixture was achieved in the aerobic pre-treatment. Pig slurry was added as co-substrate to supplement the low nitrogen levels in the olive mill wastewater. Subsequent anaerobic treatment was carried out in a 20L fixed-bed reactor at 37 degrees C and HRT between 11 and 45 days. After a long start-up period, the OLR was increased from 1.25 to 5 kg COD m(-3)day(-1) during the last 30 days, resulting in subsequent increase in overall COD removal and biogas production, up to maximum values of 85% and 29 L(biogas)L(reactor)(-1)day(-1), respectively. Methane content of the biogas produced from the anaerobic digestion ranged between 65% and 74%.

  18. Biodegradation of azo dyes in a sequential anaerobic-aerobic system.

    Science.gov (United States)

    Rajaguru, P; Kalaiselvi, K; Palanivel, M; Subburam, V

    2000-08-01

    A sequential anaerobic aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent-contaminated soil was used to degrade sulfonated azo dyes Orange G (OG), Amido black 10B (AB), Direct red 4BS (DR) and Congo red (CR). Under anaerobic conditions in a fixed-bed column using glucose as co-substrate, the azo dyes were reduced and amines were released by the bacterial biomass. The amines were completely mineralized in a subsequent aerobic treatment using the same isolates. The maximum degradation rate observed in the treatment system for OG was 60.9 mg/l per day (16.99 mg/g glucose utilized), for AB 571.3 mg/l per day (14.46 mg/g glucose utilized), for DR 112.5 mg/l per day (32.02 mg/g glucose utilized) and for CR 134.9 mg/l per day (38.9 mg/g glucose utilized).

  19. Melatonin prevents myeloperoxidase heme destruction and the generation of free iron mediated by self-generated hypochlorous acid.

    Directory of Open Access Journals (Sweden)

    Faten Shaeib

    Full Text Available Myeloperoxidase (MPO generated hypochlorous acid (HOCl formed during catalysis is able to destroy the MPO heme moiety through a feedback mechanism, resulting in the accumulation of free iron. Here we show that the presence of melatonin (MLT can prevent HOCl-mediated MPO heme destruction using a combination of UV-visible photometry, hydrogen peroxide (H2O2-specific electrode, and ferrozine assay techniques. High performance liquid chromatography (HPLC analysis showed that MPO heme protection was at the expense of MLT oxidation. The full protection of the MPO heme requires the presence of a 1:2 MLT to H2O2 ratio. Melatonin prevents HOCl-mediated MPO heme destruction through multiple pathways. These include competition with chloride, the natural co-substrate; switching the MPO activity from a two electron oxidation to a one electron pathway causing the buildup of the inactive Compound II, and its subsequent decay to MPO-Fe(III instead of generating HOCl; binding to MPO above the heme iron, thereby preventing the access of H2O2 to the catalytic site of the enzyme; and direct scavenging of HOCl. Collectively, in addition to acting as an antioxidant and MPO inhibitor, MLT can exert its protective effect by preventing the release of free iron mediated by self-generated HOCl. Our work may establish a direct mechanistic link by which MLT exerts its antioxidant protective effect in chronic inflammatory diseases with MPO elevation.

  20. Effect of co-culture and nutrients supplementation on bioremediation of crude petroleum sludge

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Mamilla Prathima; Reddy, Motakatla Venkateswar; Sarma, Ponnapalli Nageswara; Mohan, Srinivasula Reddy Venkata [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Hyderabad (India); Juwarkar, Asha [Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur (India)

    2011-10-15

    Ex-situ bioremediation of real-field crude petroleum sludge was evaluated to elucidate the role of co-culture (bioaugmentation) and external nutrients supplementation (biostimulation) under anaerobic microenvironment. Maximum removal of total petroleum hydrocarbons (TPH) was observed by integrating biostimulation with bioaugmentation (R5, 44.01%) followed by bioaugmentation alone (R4, 34.47%), co-substrate supplemented operations [R6, 23.36%; R3, 16.5%; R2, 9.88%] and control (R1, 4.36%). Aromatics fraction showed higher degradation in all the conditions studied. Fate of six selected polycyclic aromatic hydrocarbons (PAHs) was evaluated during bioremediation. Among these, four ring PAHs compounds showed good degradation by integration of biostimulation with bioaugmentation (R5) while bioaugmentation alone (R4) documented good degradation of three ring PAHs. Lower ring PAHs compounds showed good degradation with the application of biostimulation (R6). Fluorescent in situ hybridization (FISH) detected the presence of known PAHs degrading microorganisms viz., Bacillus, Pseudomonas, Acido bacteria, Sulphur reducing bacteria Firmicutes, etc. Application of biostimulation and bioaugmentation strategies alone or in combinations documented noticeable influence on the degradation of petroleum sludge. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Electrochemically driven biocatalysis of the oxygenase domain of neuronal nitric oxide synthase in indium tin oxide nanoparticles/polyvinyl alcohol nanocomposite.

    Science.gov (United States)

    Xu, Xuan; Wollenberger, Ulla; Qian, Jing; Lettau, Katrin; Jung, Christiane; Liu, Songqin

    2013-12-01

    Nitric oxide synthase (NOS) plays a critical role in a number of key physiological and pathological processes. Investigation of electron-transfer reactions in NOS would contribute to a better understanding of the nitric oxide (NO) synthesis mechanism. Herein, we describe an electrochemically driven catalytic strategy, using a nanocomposite that consisted of the oxygenase domain of neuronal NOS (D290nNOSoxy), indium tin oxide (ITO) nanoparticles and polyvinyl alcohol (PVA). Fast direct electron transfer between electrodes and D290nNOSoxy was observed with the heterogeneous electron transfer rate constant (ket) of 154.8 ± 0.1s(-1) at the scan rate of 5 Vs(-1). Moreover, the substrate N(ω)-hydroxy-L-arginine (NHA) was used to prove the concept of electrochemically driven biocatalysis of D290nNOSoxy. In the presence of the oxygen cosubstrate and tetrahydrobiopterin (BH4) cofactor, the addition of NHA caused the decreases of both oxidation current at +0.1 V and reduction current at potentials ranging from -0.149 V to -0.549 V vs Ag/AgCl. Thereafter, a series of control experiments such as in the absence of BH4 or D290nNOSoxy were performed. All the results demonstrated that D290nNOSoxy biocatalysis was successfully driven by electrodes in the presence of BH4 and oxygen. This novel bioelectronic system showed potential for further investigation of NOS and biosensor applications.

  2. Anaerobic co-digestion of Tunisian green macroalgae Ulva rigida with sugar industry wastewater for biogas and methane production enhancement.

    Science.gov (United States)

    Karray, Raida; Karray, Fatma; Loukil, Slim; Mhiri, Najla; Sayadi, Sami

    2017-03-01

    Ulva rigida is a green macroalgae, abundantly available in the Mediterranean which offers a promising source for the production of valuable biomaterials, including methane. In this study, anaerobic digestion assays in a batch mode was performed to investigate the effects of various inocula as a mixture of fresh algae, bacteria, fungi and sediment collected from the coast of Sfax, on biogas production from Ulva rigida. The results revealed that the best inoculum to produce biogas and feed an anaerobic reactor is obtained through mixing decomposed macroalgae with anaerobic sludge and water, yielding into 408mL of biogas. The process was then investigated in a sequencing batch reactor (SBR) which led to an overall biogas production of 375mL with 40% of methane. Further co-digestion studies were performed in an anaerobic up-flow bioreactor using sugar wastewater as a co-substrate. A high biogas production yield of 114mL g(-1) VSadded was obtained with 75% of methane. The co-digestion proposed in this work allowed the recovery of natural methane, providing a promising alternative to conventional anaerobic microbial fermentation using Tunisian green macroalgae. Finally, in order to identify the microbial diversity present in the reactor during anaerobic digestion of Ulva rigida, the prokaryotic diversity was investigated in this bioreactor by the denaturing gradient gel electrophoresis (DGGE) method targeting the 16S rRNA gene. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Utilization of Biodiesel By-Products for Biogas Production

    Science.gov (United States)

    Kolesárová, Nina; Hutňan, Miroslav; Bodík, Igor; Špalková, Viera

    2011-01-01

    This contribution reviews the possibility of using the by-products from biodiesel production as substrates for anaerobic digestion and production of biogas. The process of biodiesel production is predominantly carried out by catalyzed transesterification. Besides desired methylesters, this reaction provides also few other products, including crude glycerol, oil-pressed cakes, and washing water. Crude glycerol or g-phase is heavier separate liquid phase, composed mainly by glycerol. A couple of studies have demonstrated the possibility of biogas production, using g-phase as a single substrate, and it has also shown a great potential as a cosubstrate by anaerobic treatment of different types of organic waste or energy crops. Oil cakes or oil meals are solid residues obtained after oil extraction from the seeds. Another possible by-product is the washing water from raw biodiesel purification, which is an oily and soapy liquid. All of these materials have been suggested as feasible substrates for anaerobic degradation, although some issues and inhibitory factors have to be considered. PMID:21403868

  4. Novel degradation pathway and kinetic analysis for buprofezin removal by newly isolated Bacillus sp.

    Science.gov (United States)

    Wang, Guangli; Xu, Dayong; Xiong, Minghua; Zhang, Hui; Li, Feng; Liu, Yuan

    2016-09-15

    Given the intensive and widespread application of the pesticide, buprofezin, its environmental residues potentially pose a problem; yet little is known about buprofezin's kinetic and metabolic behaviors. In this study, a novel gram-positive strain, designated BF-5, isolated from aerobic activated sludge, was found to be capable of metabolizing buprofezin as its sole energy, carbon, and nitrogen source. Based on its physiological and biochemical characteristics, other aspects of its phenotype, and a phylogenetic analysis, strain BF-5 was identified as Bacillus sp. This study investigated the effect of culture conditions on bacterial growth and substrate degradation, such as pH, temperature, initial concentration, different nitrogen source, and additional nitrogen sources as co-substrates. The degradation rate parameters, qmax, Ks, Ki and Sm were determined to be 0.6918 h(-1), 105.4 mg L(-1), 210.5 mg L(-1), and 148.95 mg L(-1) respectively. The capture of unpublished potential metabolites by gas chromatography-mass spectrometry (GC-MS) analysis has led to the proposal of a novel degradation pathway. Taken together, our results clarify buprofezin's biodegradation pathway(s) and highlight the promising potential of strain BF-5 in bioremediation of buprofezin-contaminated environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Rue-Van Es, J.E. La.

    1993-05-01

    Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs.

  6. The initial metabolic conversion of levulinic acid in Cupriavidus necator.

    Science.gov (United States)

    Jaremko, Matt; Yu, Jian

    2011-09-20

    Levulinic acid or 4-ketovaleric acid is a potential renewable substrate for production of polyhydroxyalkanoates. In this work, the initial reactions of LA metabolism by Cupriavidus necator were examined in vitro. The organic acid was converted by membrane-bound crude enzymes obtained from the cells pre-grown on LA, while no LA activity was detected from cells pre-grown on acetic acid. Acetyl-CoA and propionyl-CoA were two major intermediates in the initial reactions of LA conversion. A mass balance on propionyl-CoA accounts for 84 mol% of LA added in vitro. It explains an interesting phenomenon that 3-hydroxbutyrate and 3-hydroxyvalerate are two major monomers of the biopolyester formed from LA, instead of 4-hydroxvalerate that has the similar chemical structure of LA as the precursor. A Monod model was used to describe the kinetics of LA utilization as a sole carbon source or a co-substrate of glucose and fructose. The μ(max) and K(m) of LA alone were 0.26 h⁻¹ and 0.01 g/L, respectively. The content and composition of PHA are also dependent on the culture conditions such as carbon to nitrogen ratio. The in vitro observation is supported by the high utilization rate of LA and the high molar percentage of 3HB and 3HV in the PHA derived from LA. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Enzymatic Synthesis of Glucose-Based Fatty Acid Esters in Bisolvent Systems Containing Ionic Liquids or Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kai-Hua Zhao

    2016-09-01

    Full Text Available Sugar fatty acid esters (SFAEs are biocompatible nonionic surfactants with broad applications in food, cosmetic, and pharmaceutical industries. They can be synthesized enzymatically with many advantages over their chemical synthesis. In this study, SFAE synthesis was investigated by using two reactions: (1 transesterification of glucose with fatty acid vinyl esters and (2 esterification of methyl glucoside with fatty acids, catalyzed by Lipozyme TLIM and Novozym 435 respectively. Fourteen ionic liquids (ILs and 14 deep eutectic solvents (DESs were screened as solvents, and the bisolvent system composed of 1-hexyl-3-methylimidazolium trifluoromethylsulfonate ([HMIm][TfO] and 2-methyl-2-butanol (2M2B was the best for both reactions, yielding optimal productivities (769.6 and 397.5 µmol/h/g, respectively which are superior to those reported in the literature. Impacts of different reaction conditions were studied for both reactions. Response surface methodology (RSM was employed to optimize the transesterification reaction. Results also demonstrated that as co-substrate, methyl glucoside yielded higher conversions than glucose, and that conversions increased with an increase in the chain length of the fatty acid moieties. DESs were poor solvents for the above reactions presumably due to their high viscosity and high polarity.

  8. Biodegradation of Basic Violet 3 by Candida krusei isolated from textile wastewater.

    Science.gov (United States)

    Deivasigamani, Charumathi; Das, Nilanjana

    2011-11-01

    Basic Violet 3 (BV) belongs to the most important group of synthetic colorants and is used extensively in textile industries. It is considered as xenobiotic compound which is recalcitrant to biodegradation. As Candida krusei could not use BV as sole carbon source, experiments were conducted to study the effect of cosubstrates on decolorization of BV in semi synthetic medium using glucose, sucrose, lactose, maltose, yeast extract, peptone, urea and ammonium sulphate. Maximum decolorization (74%) was observed in media supplemented with sucrose. Use of sugarcane bagasse extract as sole nutrient source showed 100% decolorization of BV within 24 h under optimized condition. UV-visible, FTIR spectral analysis and HPLC analysis confirmed the biodegradation of BV. Six degradation products were isolated and identified. We propose the biodegradation pathway for BV which occurs via stepwise reduction and demethylation process to yield mono-, di-, tri-, tetra-, penta- and hexa-demethylated BV species which was degraded completely. The study of the enzymes responsible for decolorization showed the activities of lignin peroxidase, lacasse, tyrosinase, NADH-DCIP reductase, MG reductase and azoreductase in cells before and after decolorization. A significant increase in activities of NADH-DCIP reductase and laccase was observed in the cells after decolorization. The yeast C. krusei could show the ability to decolorize the textile dye BV using inexpensive source like sugarcane bagasse extract for decolorization.

  9. Cometabolic bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2009-02-15

    Cometabolic bioremediation is probably the most under appreciated bioremediation strategy currently available. Cometabolism strategies stimulate only indigenous microbes with the ability to degrade the contaminant and cosubstrate e.g. methane, propane, toluene and others. This highly targeted stimulation insures that only those microbes that can degrade the contaminant are targeted, thus reducing amendment costs, well and formation plugging, etc. Cometabolic bioremediation has been used on some of the most recalcitrant contaminants, e.g. PCE, TCE, MTBE, TNT, dioxane, atrazine, etc. Methanotrophs have been demonstrated to produce methane monooxygense, an oxidase that can degrade over 300 compounds. Cometabolic bioremediation also has the advantage of being able to degrade contaminants to trace concentrations, since the biodegrader is not dependent on the contaminant for carbon or energy. Increasingly we are finding that in order to protect human health and the environment that we must remediate to lower and lower concentrations, especially for compounds like endocrine disrupters, thus cometabolism may be the best and maybe the only possibility that we have to bioremediate some contaminants.

  10. Go it alone: four-electron oxidations by mononuclear non-heme iron enzymes.

    Science.gov (United States)

    Peck, Spencer C; van der Donk, Wilfred A

    2017-04-01

    This review discusses the current mechanistic understanding of a group of mononuclear non-heme iron-dependent enzymes that catalyze four-electron oxidation of their organic substrates without the use of any cofactors or cosubstrates. One set of enzymes acts on α-ketoacid-containing substrates, coupling decarboxylation to oxygen activation. This group includes 4-hydroxyphenylpyruvate dioxygenase, 4-hydroxymandelate synthase, and CloR involved in clorobiocin biosynthesis. A second set of enzymes acts on substrates containing a thiol group that coordinates to the iron. This group is comprised of isopenicillin N synthase, thiol dioxygenases, and enzymes involved in the biosynthesis of ergothioneine and ovothiol. The final group of enzymes includes HEPD and MPnS that both carry out the oxidative cleavage of the carbon-carbon bond of 2-hydroxyethylphosphonate but generate different products. Commonalities amongst many of these enzymes are discussed and include the initial substrate oxidation by a ferric-superoxo-intermediate and a second oxidation by a ferryl species.

  11. Potential of Penicillium Species in the Bioremediation Field

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Leitão

    2009-04-01

    Full Text Available The effects on the environment of pollution, particularly that caused by various industrial activities, have been responsible for the accelerated fluxes of organic and inorganic matter in the ecosphere. Xenobiotics such as phenol, phenolic compounds, polycyclic aromatic hydrocarbons (PAHs, and heavy metals, even at low concentrations, can be toxic to humans and other forms of life. Many of the remediation technologies currently being used for contaminated soil and water involve not only physical and chemical treatment, but also biological processes, where microbial activity is the responsible for pollutant removal and/or recovery. Fungi are present in aquatic sediments, terrestrial habitats and water surfaces and play a significant part in natural remediation of metal and aromatic compounds. Fungi also have advantages over bacteria since fungal hyphae can penetrate contaminated soil, reaching not only heavy metals but also xenobiotic compounds. Despite of the abundance of such fungi in wastes, penicillia in particular have received little attention in bioremediation and biodegradation studies. Additionally, several studies conducted with different strains of imperfecti fungi, Penicillium spp. have demonstrated their ability to degrade different xenobiotic compounds with low co-substrate requirements, and could be potentially interesting for the development of economically feasible processes for pollutant transformation.

  12. Xylitol production at high temperature by engineered Kluyveromyces marxianus.

    Science.gov (United States)

    Zhang, Jia; Zhang, Biao; Wang, Dongmei; Gao, Xiaolian; Hong, Jiong

    2014-01-01

    Several recombinant Kluyveromyces marxianus strains were constructed through overexpressing the Neurospora crassa xylose reductase genes. YZJ015, which maintained the original xylitol dehydrogenase gene, produced xylitol with the highest productivity (1.49 g L(-1) h(-1)) from 100 g L(-1) xylose at 42 °C. Even at 45 °C, YZJ015 was still able to produce 60.03 g L(-1) xylitol from 100 g L(-1) xylose with a productivity of 1.25 g L(-1)h(-1). In addition, for 20 rounds of cell recycling at 42 °C, YZJ015 produced 71.35 g L(-1) xylitol from 100 g L(-1) xylose with a productivity of 4.43 g L(-1) h(-1) per cycle. YZJ017, in which the xylitol dehydrogenase gene was disrupted, produced 100.02 g L(-1) xylitol at a yield of 1.01 g g(-1) from 100 g L(-1) xylose with 40 g L(-1) glycerol as co-substrate at 42 °C. These engineered strains provide an excellent foundation for xylitol production at elevated temperatures.

  13. Modeling of spherical fluorescent glucose microsensor systems: design of enzymatic smart tattoos.

    Science.gov (United States)

    Brown, J Quincy; McShane, Michael J

    2006-03-15

    A two-substrate mathematical model of microspherical optical enzymatic glucose sensors is presented. The sensors are based on the well-known oxidation of glucose by glucose oxidase, and are constructed by the encapsulation of glucose oxidase within hydrogel microspheres coated with ultrathin polyelectrolyte multilayer films. In order to measure glucose via changes in oxygen concentration, a fluorescent oxygen indicator is co-encapsulated with the enzyme. The model was used to predict the temporal and spatial distributions of glucose and oxygen within the sphere for step increases in bulk glucose concentration. In addition, the model was used to observe the effect of varying sensor parameters, namely sphere size, film thickness, enzyme concentration, and mass transport of substrate and co-substrate within the sphere and film coatings, on the response of the sensors. A major finding was that the application of {PSS/PAH} films as thin as 12 nm can drastically improve the sensor performance over uncoated sensors based on calcium alginate microspheres. The model is proposed as an important tool for a priori design of these complex sensor structures.

  14. Anaerobic and aerobic transformation of TNT

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  15. A root-expressed L-phenylalanine:4-hydroxyphenylpyruvate aminotransferase is required for tropane alkaloid biosynthesis in Atropa belladonna.

    Science.gov (United States)

    Bedewitz, Matthew A; Góngora-Castillo, Elsa; Uebler, Joseph B; Gonzales-Vigil, Eliana; Wiegert-Rininger, Krystle E; Childs, Kevin L; Hamilton, John P; Vaillancourt, Brieanne; Yeo, Yun-Soo; Chappell, Joseph; DellaPenna, Dean; Jones, A Daniel; Buell, C Robin; Barry, Cornelius S

    2014-09-01

    The tropane alkaloids, hyoscyamine and scopolamine, are medicinal compounds that are the active components of several therapeutics. Hyoscyamine and scopolamine are synthesized in the roots of specific genera of the Solanaceae in a multistep pathway that is only partially elucidated. To facilitate greater understanding of tropane alkaloid biosynthesis, a de novo transcriptome assembly was developed for Deadly Nightshade (Atropa belladonna). Littorine is a key intermediate in hyoscyamine and scopolamine biosynthesis that is produced by the condensation of tropine and phenyllactic acid. Phenyllactic acid is derived from phenylalanine via its transamination to phenylpyruvate, and mining of the transcriptome identified a phylogenetically distinct aromatic amino acid aminotransferase (ArAT), designated Ab-ArAT4, that is coexpressed with known tropane alkaloid biosynthesis genes in the roots of A. belladonna. Silencing of Ab-ArAT4 disrupted synthesis of hyoscyamine and scopolamine through reduction of phenyllactic acid levels. Recombinant Ab-ArAT4 preferentially catalyzes the first step in phenyllactic acid synthesis, the transamination of phenylalanine to phenylpyruvate. However, rather than utilizing the typical keto-acid cosubstrates, 2-oxoglutarate, pyruvate, and oxaloacetate, Ab-ArAT4 possesses strong substrate preference and highest activity with the aromatic keto-acid, 4-hydroxyphenylpyruvate. Thus, Ab-ArAT4 operates at the interface between primary and specialized metabolism, contributing to both tropane alkaloid biosynthesis and the direct conversion of phenylalanine to tyrosine. © 2014 American Society of Plant Biologists. All rights reserved.

  16. A Root-Expressed l-Phenylalanine:4-Hydroxyphenylpyruvate Aminotransferase Is Required for Tropane Alkaloid Biosynthesis in Atropa belladonna[C][W

    Science.gov (United States)

    Bedewitz, Matthew A.; Góngora-Castillo, Elsa; Uebler, Joseph B.; Gonzales-Vigil, Eliana; Wiegert-Rininger, Krystle E.; Childs, Kevin L.; Hamilton, John P.; Vaillancourt, Brieanne; Yeo, Yun-Soo; Chappell, Joseph; DellaPenna, Dean; Jones, A. Daniel; Buell, C. Robin; Barry, Cornelius S.

    2014-01-01

    The tropane alkaloids, hyoscyamine and scopolamine, are medicinal compounds that are the active components of several therapeutics. Hyoscyamine and scopolamine are synthesized in the roots of specific genera of the Solanaceae in a multistep pathway that is only partially elucidated. To facilitate greater understanding of tropane alkaloid biosynthesis, a de novo transcriptome assembly was developed for Deadly Nightshade (Atropa belladonna). Littorine is a key intermediate in hyoscyamine and scopolamine biosynthesis that is produced by the condensation of tropine and phenyllactic acid. Phenyllactic acid is derived from phenylalanine via its transamination to phenylpyruvate, and mining of the transcriptome identified a phylogenetically distinct aromatic amino acid aminotransferase (ArAT), designated Ab-ArAT4, that is coexpressed with known tropane alkaloid biosynthesis genes in the roots of A. belladonna. Silencing of Ab-ArAT4 disrupted synthesis of hyoscyamine and scopolamine through reduction of phenyllactic acid levels. Recombinant Ab-ArAT4 preferentially catalyzes the first step in phenyllactic acid synthesis, the transamination of phenylalanine to phenylpyruvate. However, rather than utilizing the typical keto-acid cosubstrates, 2-oxoglutarate, pyruvate, and oxaloacetate, Ab-ArAT4 possesses strong substrate preference and highest activity with the aromatic keto-acid, 4-hydroxyphenylpyruvate. Thus, Ab-ArAT4 operates at the interface between primary and specialized metabolism, contributing to both tropane alkaloid biosynthesis and the direct conversion of phenylalanine to tyrosine. PMID:25228340

  17. Two Decades of Laccases: Advancing Sustainability in the Chemical Industry.

    Science.gov (United States)

    Cannatelli, Mark D; Ragauskas, Arthur J

    2017-01-01

    Given the current state of environmental affairs and that our future on this planet as we know it is in jeopardy, research and development into greener and more sustainable technologies within the chemical and forest products industries is at its peak. Given the global scale of these industries, the need for environmentally benign practices is propelling new green processes. These challenges are also impacting academic research and our reagents of interest are laccases. These enzymes are employed in a variety of biotechnological applications due to their native function as catalytic oxidants. They are about as green as it gets when it comes to chemical processes, requiring O2 as their only co-substrate and producing H2 O as the sole by-product. The following account will review our twenty year journey on the use of these enzymes within our research group, from their initial use in biobleaching of kraft pulps and for fiber modification within the pulp and paper industry, to their current application as green catalytic oxidants in the field of synthetic organic chemistry.

  18. Economic viability of present-day biomass energy installations; Wirtschaftlichkeit von heutigen Biomasse-Energieanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Markus Sommerhalder, M.; Schelske, O. [Ernst Basler und Partner AG, Zuerich (Switzerland); Nussbaumer, T. [Verenum, Zuerich (Switzerland); Engeli, H. [Engeli Engineering, Neerach (Switzerland); Membrez, Y.; Ndoh, M.; Tacchini, C. [EREP SA, Aclens (Switzerland)

    2007-03-15

    This illustrated, comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at the economic viability of biomass energy installations. The installations examined included wood-fired installations, biogas installations and those using bio-diesel and bio-ethanol. The system boundaries involved are defined and various factors that influence cost calculations are examined. The resulting heat and electricity prices for various energy sources and systems are presented and discussed. Examples of small and large-scale installations are presented. For wood-energy, combined heat and power system producing electricity at powers of 1 to 5 MWe are looked at and the various factors influencing their viability are discussed. Biogas installations of various sizes are discussed and the differing investment costs involved are commented on. Here, large industrial installations using communal green wastes are also examined and the influence of communal waste-collection charges on the price for the electricity generated is discussed, as is the influence of the market for the residual compost produced. The production and use of biogas in public wastewater treatment plants is also looked at, including the use of co-substrates. As far as biogenic liquid fuels such as bio-diesel and bio-ethanol are concerned, the report takes a brief look at the situation concerning installations in Switzerland and reviews the production costs involved. Various conclusions are drawn for the various energy sources reviewed as well as for the prices for heat and electrical energy obtained.

  19. A structural basis for the pH-dependent xanthophyll cycle in Arabidopsis thaliana.

    Science.gov (United States)

    Arnoux, Pascal; Morosinotto, Tomas; Saga, Giorgia; Bassi, Roberto; Pignol, David

    2009-07-01

    Plants adjust their photosynthetic activity to changing light conditions. A central regulation of photosynthesis depends on the xanthophyll cycle, in which the carotenoid violaxanthin is converted into zeaxanthin in strong light, thus activating the dissipation of the excess absorbed energy as heat and the scavenging of reactive oxygen species. Violaxanthin deepoxidase (VDE), the enzyme responsible for zeaxanthin synthesis, is activated by the acidification of the thylakoid lumen when photosynthetic electron transport exceeds the capacity of assimilatory reactions: at neutral pH, VDE is a soluble and inactive enzyme, whereas at acidic pH, it attaches to the thylakoid membrane where it binds its violaxanthin substrate. VDE also uses ascorbate as a cosubstrate with a pH-dependent Km that may reflect a preference for ascorbic acid. We determined the structures of the central lipocalin domain of VDE (VDEcd) at acidic and neutral pH. At neutral pH, VDEcd is monomeric with its active site occluded within a lipocalin barrel. Upon acidification, the barrel opens up and the enzyme appears as a dimer. A channel linking the two active sites of the dimer can harbor the entire carotenoid substrate and thus may permit the parallel deepoxidation of the two violaxanthin beta-ionone rings, making VDE an elegant example of the adaptation of an asymmetric enzyme to its symmetric substrate.

  20. Biotin determination in food supplements by an electrochemical magneto biosensor.

    Science.gov (United States)

    Kergaravat, Silvina V; Gómez, Gabriel A; Fabiano, Silvia N; Laube Chávez, Tamara I; Pividori, María I; Hernández, Silvia R

    2012-08-15

    An electrochemical magneto biosensor for the rapid determination of biotin in food samples is reported. The affinity reaction was performed on streptavidin-modified magnetic microbeads as a solid support in a direct competitive format. The biotinylated horseradish peroxidase enzyme (biotin-HRP) competes with free biotin in the sample for the binding sites of streptavidin on the magnetic microbeads. The modified magnetic beads were then easily captured by a magneto graphite-epoxy composite electrode and the electrochemical signal was based on the enzymatic activity of the HRP enzyme under the addition of H(2)O(2) as the substrate and o-phenilendiamine as cosubstrate. The response was electrochemically detected by square wave voltammetry. The limit of detection was 8.4×10(-8) mol L(--1) of biotin (20 μg L(--1)) with a dynamic range from 0.94 to 2.4×10(-7) mol L(--1). Biotin-fortified commercial dietary supplement and infant formula samples were evaluated obtaining good performances in the results. Total time of analysis was 40 min per 20 assays.

  1. The orphan transporter v7-3 (slc6a15) is a Na+-dependent neutral amino acid transporter (B0AT2)

    DEFF Research Database (Denmark)

    Bröer, Angelika; Tietze, Nadine; Kowalczuk, Sonja;

    2006-01-01

    Transporters of the SLC6 (solute carrier 6) family play an important role in the removal of neurotransmitters in brain tissue and in amino acid transport in epithelial cells. In the present study, we demonstrate that mouse v7-3 (slc6a15) encodes a transporter for neutral amino acids...... low-affinity substrates of the transporter, with K(0.5) values in the millimolar range. Transport of neutral amino acids via B(0)AT2 was Na+-dependent, Cl--independent and electrogenic. Superfusion of mouse B(0)AT2-expressing oocytes with amino acid substrates generated robust inward currents. Na......+-activation kinetics of proline transport and uptake under voltage clamp suggested a 1:1 Na+/amino acid co-transport stoichiometry. Susbtrate and co-substrate influenced each other's K(0.5) values, suggesting that they share the same binding site. A mouse B(0)AT2-like transport activity was detected in synaptosomes...

  2. Vitamin A as an enzyme that catalyzes the reduction of MTT to formazan by vitamin C.

    Science.gov (United States)

    Chakrabarti, R; Kundu, S; Kumar, S; Chakrabarti, R

    2000-09-18

    The tetrazolium salt 3(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) is reduced to formazan by the succinate dehydrogenase system of active mitochondria, and hence, specifically used to assay for the viable cells, such as measurement of cell proliferation, cytotoxicity, and cell number. However, in the present study we have shown that some component specifically present in M199 but not in RPMI 1640 media can reduce MTT to formazan in the absence of a living system. Further study revealed that ascorbic acid reduced MTT to formazan, which was profoundly increased by a very small amount of retinol, whereas retinol alone had no effect. Oxidation of ascorbic acid by H(2)O(2) destroyed its ability to reduce MTT. The rate of MTT reduction was directly proportional to the concentration of MTT in the absence of retinol, but approached a zero-order state beyond a certain concentration of MTT in the presence of retinol. Furthermore, retinol remained unchanged after the completion of the reaction. Taken together, these results showed that retinol acts as a reductase that catalyzes the reduction of MTT to formazan using ascorbic acid as the cosubstrate (electron donor).

  3. Batch anaerobic co-digestion of waste activated sludge and microalgae (Chlorella sorokiniana) at mesophilic temperature.

    Science.gov (United States)

    Beltrán, Carolina; Jeison, David; Fermoso, Fernando G; Borja, Rafael

    2016-08-23

    The microalgae Chlorella sorokiniana are used as co-substrate for waste activated sludge (WAS) anaerobic digestion. The specific objective of this research was to evaluate the feasibility of improving methane production from anaerobic digestion of WAS in co-digestion with this microalga, based on an optimized mixture percentage. Thus, the anaerobic co-digestion of both substrates aims to overcome the drawbacks of the anaerobic digestion of single WAS, simultaneously improving its management. Different co-digestion mixtures (0% WAS-100% microalgae; 25% WAS-75% microalgae; 50% WAS-50% microalgae; 75% WAS-25% microalgae; 100% WAS-0% microalgae) were studied. The highest methane yield (442 mL CH4/g VS) was obtained for the mixture with 75% WAS and 25% microalgae. This value was 22% and 39% higher than that obtained in the anaerobic digestion of the sole substrates WAS and microalgae, respectively, as well as 16% and 25% higher than those obtained for the co-digestion mixtures with 25% WAS and 75% microalgae and 50% WAS and 50% microalgae, respectively. The kinetic constant of the process increased 42%, 42% and 12%, respectively, for the mixtures with 25%, 50% and 75% of WAS compared to the substrate without WAS. Anaerobic digestion of WAS, together with C. sorokiniana, has been clearly improved by ensuring its viability, suitability and efficiency.

  4. Thiol peroxidase-like activity of some intramolecularly coordinated diorganyl diselenides

    Indian Academy of Sciences (India)

    Sangit Kumar; Harkesh B Singh

    2005-11-01

    Several new diaryl diselenides having intramolecular coordinating groups have been synthesized by ortho-lithiation/Na2Se2 routes in good yield. Bis[2-(N-phenylferrocenecarboxamide)] diselenide (10), bis[2-(N-tert-butylferrocenecarboxamide)] diselenide (11), ()()-bis[2(--phenethylferrocenecarboxamide)] diselenide (12) were synthesized by the ortho-lithiation route. Bis[2-(N,N-dimethylaminomethylnaphthyl)] diselenide (13) was synthesized by lithium/bromide exchange reaction whereas bis(2,4-dinitrophenyl) diselenide (14) was prepared by the reaction of disodium diselenide with 2,4- dinitro-1-chlorobenzene. Thiol peroxidase-like activities of the diorganodiselenides have been evaluated by using H2O2 as substrate and PhSH as cosubstrate. Diselenides (13) and (14) with dimethylaminomethyl- or nitro-donor groups in close proximity to selenium, show much better thiol peroxidase-like activities compared to diselenides 10-12 with amide donor groups. Cyclic voltammetry study of diselenides 10-12 derived from redox-active ferrocenamide has been carried out.

  5. Optimal management of substrates in anaerobic co-digestion: An ant colony algorithm approach.

    Science.gov (United States)

    Verdaguer, Marta; Molinos-Senante, María; Poch, Manel

    2016-04-01

    Sewage sludge (SWS) is inevitably produced in urban wastewater treatment plants (WWTPs). The treatment of SWS on site at small WWTPs is not economical; therefore, the SWS is typically transported to an alternative SWS treatment center. There is increased interest in the use of anaerobic digestion (AnD) with co-digestion as an SWS treatment alternative. Although the availability of different co-substrates has been ignored in most of the previous studies, it is an essential issue for the optimization of AnD co-digestion. In a pioneering approach, this paper applies an Ant-Colony-Optimization (ACO) algorithm that maximizes the generation of biogas through AnD co-digestion in order to optimize the discharge of organic waste from different waste sources in real-time. An empirical application is developed based on a virtual case study that involves organic waste from urban WWTPs and agrifood activities. The results illustrate the dominate role of toxicity levels in selecting contributions to the AnD input. The methodology and case study proposed in this paper demonstrate the usefulness of the ACO approach in supporting a decision process that contributes to improving the sustainability of organic waste and SWS management.

  6. Anaerobic co-digestion of sewage sludge and primary clarifier skimmings for increased biogas production.

    Science.gov (United States)

    Alanya, S; Yilmazel, Y D; Park, C; Willis, J L; Keaney, J; Kohl, P M; Hunt, J A; Duran, M

    2013-01-01

    The objective of the study was to identify the impact of co-digesting clarifier skimmings on the overall methane generation from the treatment plant and additional energy value of the increased methane production. Biogas production from co-digesting clarifier skimmings and sewage sludge in pilot-scale fed-batch mesophilic anaerobic digesters has been evaluated. The digester was fed with increasing quantities of clarifier skimmings loads: 1.5, 2.6, 3.5 and 7.0 g COD equivalent/(L·d) (COD: chemical oxygen demand). Average volatile solids reduction of 65% was achieved in the scum-fed digester, compared with 51% in the control digester. Average 69% COD removal was achieved at highest scum loading (7 g COD eq/(L·d)) with approximate methane yield of 250 L CH(4)/kg COD fed (4 ft(3)/lb COD fed). The results show that scum as co-substrate in anaerobic digestion systems improves biogas yields while a 29% increase in specific CH(4) yield could be achieved when scum load is 7 g COD eq/(L·d). Based on the pilot-scale study results and full-scale data from South East Water Pollution Control Plant and Northeast Water Pollution Control Plant the expected annual energy recovery would be approximately 1.7 billion BTUs or nearly 0.5 million kWh.

  7. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Mark Eiteman

    2007-07-31

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzymes PEP carboxylase and pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The study reports on strain development and process development. In the area of strain development, knockouts in genes which divert carbon from the enzymatic steps involved in CO{sub 2} consumption were completed, and were shown not to affect significantly the rate of CO{sub 2} sequestration and succinic acid generation. Furthermore, the pyc gene encoding for pyruvate carboxylase proved to be unstable when integrated onto the chromosome. In the area of process development, an optimal medium, pH and base counterion were obtained, leading to a sequestration rate as great as 800 mg/Lh. Detailed studies of gas phase composition demonstrated that CO{sub 2} composition has a significant affect on CO{sub 2} sequestration, while the presence of 'toxic' compounds in the gas, including NO{sub 2}, CO and SO{sub 2} did not have a detrimental effect on sequestration. Some results on prolonging the rate of sequestration indicate that enzyme activities decrease with time, suggesting methods to prolong enzyme activity may benefit the overall process.

  8. Treatment of linear alkylbenzene sulfonate in a horizontal anaerobic immobilized biomass reactor.

    Science.gov (United States)

    Duarte, I C S; Oliveira, L L; Saavedra, N K; Fantinatti-Garboggini, F; Menezes, C B A; Oliveira, V M; Varesche, M B A

    2010-01-01

    Linear alkylbenzene sulfonate (LAS) is an anionic surfactant widely used to manufacture detergents and found in domestic and industrial wastewater. LAS removal was evaluated in a horizontal anaerobic immobilized biomass reactor. The system was filled with polyurethane foam and inoculated with sludge that was withdrawn from an up flow anaerobic sludge blanket reactor that is used to treat swine wastewater. The reactor was fed with easily degradable substrates and a solution of commercial LAS for 313 days. The hydraulic retention time applied was 12h. The system was initially operated without detergent and resulted to 94% reduction of demand. The mass balance in the system indicated that the LAS removal efficiency was 45% after 18 0days. From the 109 th day to the 254 th day, a removal efficiency of 32% was observed. The removal of LAS was approximately 40% when 1500 mg of LAS were applied in the absence of co-substrates suggesting that the LAS molecules were used selectively. Microscopic analyses of the biofilm revealed diverse microbial morphologies and denaturing gradient gel electrophoresis profiling showed variations in the total bacteria and sulfate-reducing bacteria populations. 16S rRNA sequencing and phylogenetic analyses demonstrated that members of the order Clostridiales were the major components of the bacterial community in the last step of the reactor operation.

  9. Optimization of linear alkylbenzene sulfonate (LAS) degradation in UASB reactors by varying bioavailability of LAS, hydraulic retention time and specific organic load rate.

    Science.gov (United States)

    Okada, Dagoberto Y; Delforno, Tiago P; Esteves, Andressa S; Sakamoto, Isabel K; Duarte, Iolanda C S; Varesche, Maria B A

    2013-01-01

    Degradation of linear alkylbenzene sulfonate (LAS) in UASB reactors was optimized by varying the bioavailability of LAS based on the concentration of biomass in the system (1.3-16 g TS/L), the hydraulic retention time (HRT), which was operated at 6, 35 or 80 h, and the concentration of co-substrates as specific organic loading rates (SOLR) ranging from 0.03-0.18 g COD/g TVS.d. The highest degradation rate of LAS (76%) was related to the lowest SOLR (0.03 g COD/g TVS.d). Variation of the HRT between 6 and 80 h resulted in degradation rates of LAS ranging from 18% to 55%. Variation in the bioavailability of LAS resulted in discrete changes in the degradation rates (ranging from 37-53%). According to the DGGE profiles, the archaeal communities exhibited greater changes than the bacterial communities, especially in biomass samples that were obtained from the phase separator. The parameters that exhibited more influence on LAS degradation were the SOLR followed by the HRT.

  10. Amino acids in the rhizosphere: from plants to microbes.

    Science.gov (United States)

    Moe, Luke A

    2013-09-01

    Often referred to as the "building blocks of proteins", the 20 canonical proteinogenic amino acids are ubiquitous in biological systems as the functional units in proteins. Sometimes overlooked are their varying additional roles that include serving as metabolic intermediaries, playing structural roles in bioactive natural products, acting as cosubstrates in enzymatic transformations, and as key regulators of cellular physiology. Amino acids can also serve as biological sources of both carbon and nitrogen and are found in the rhizosphere as a result of lysis or cellular efflux from plants and microbes and proteolysis of existing peptides. While both plants and microbes apparently prefer to take up nitrogen in its inorganic form, their ability to take up and use amino acids may confer a selective advantage in certain environments where organic nitrogen is abundant. Further, certain amino acids (e.g., glutamate and proline) and their betaines (e.g., glycine betaine) serve as compatible solutes necessary for osmoregulation in plants and microbes and can undergo rapid cellular flux. This ability is of particular importance in an ecological niche such as the rhizosphere, which is prone to significant variations in solute concentrations. Amino acids are also shown to alter key phenotypes related to plant root growth and microbial colonization, symbiotic interactions, and pathogenesis in the rhizosphere. This review will focus on the sources, transport mechanisms, and potential roles of the 20 canonical proteinogenic amino acids in the rhizosphere.

  11. Action patterns of amylolytic enzymes as determined by the [1-14C]malto-oligosaccharide mapping method.

    Science.gov (United States)

    Pazur, J H; Marchetti, N T

    1992-04-06

    A valuable technique for oligosaccharide mapping, utilizing radioactive malto-oligosaccharides, multiple-ascent p.c., and radioautography, has been developed for identifying the action patterns of the glucoamylase isozymes, alpha-amylases, beta-amylase, glucosyltransferase, and glucanosyltransferase. The glucoamylase isozymes act by multi-chain mechanisms on malto-oligosaccharides and most likely on starch and glycogen. The alpha-amylases act endo-wise and randomly hydrolyze alpha-(1----4)- but not alpha-(1----6)-glucosidic bonds. These amylases may act by single-chain and/or multi-chain mechanisms, depending on the number of hydrolytic attacks per single encounter of the enzyme and the substrate. The beta-amylases hydrolyze malto-oligosaccharides by a multi-chain mechanism. A fungal glucosyltransferase from Aspergillus niger transfers glucose units by a single-chain mechanism from maltose to glucosyl acceptors to yield new gluco-oligosaccharides with alpha-(1----4) and alpha-(1----6) linkages. A novel type of transferase isolated from Bacillus subtilis acts by a multi-chain mechanism and transfers segments of 2 to 5 glucose residues from malto-oligosaccharides to acceptor co-substrates. An alpha-amylase from the same organism removes maltotriose units from the non-reducing ends of oligosaccharides by a multi-chain mechanism.

  12. Anaerobic digestion and co-digestion of slaughterhouse waste (SHW): influence of heat and pressure pre-treatment in biogas yield.

    Science.gov (United States)

    Cuetos, M J; Gómez, X; Otero, M; Morán, A

    2010-10-01

    Mesophilic anaerobic digestion (34+/-1 degrees C) of pre-treated (for 20 min at 133 degrees C, >3 bar) slaughterhouse waste and its co-digestion with the organic fraction of municipal solid waste (OFMSW) have been assessed. Semi-continuously-fed digesters worked with a hydraulic retention time (HRT) of 36 d and organic loading rates (OLR) of 1.2 and 2.6 kg VS(feed)/m(3)d for digestion and co-digestion, respectively, with a previous acclimatization period in all cases. It was not possible to carry out an efficient treatment of hygienized waste, even less so when OFMSW was added as co-substrate. These digesters presented volatile fatty acids (VFA), long chain fatty acids (LCFA) and fats accumulation, leading to instability and inhibition of the degradation process. The aim of applying a heat and pressure pre-treatment to promote splitting of complex lipids and nitrogen-rich waste into simpler and more biodegradable constituents and to enhance biogas production was not successful. These results indicate that the temperature and the high pressure of the pre-treatment applied favoured the formation of compounds that are refractory to anaerobic digestion. The pre-treated slaughterhouse wastes and the final products of these systems were analyzed by FTIR and TGA. These tools verified the existence of complex nitrogen-containing polymers in the final effluents, confirming the formation of refractory compounds during pre-treatment.

  13. Aromatic amine degradation in a UASB/CSTR sequential system treating Congo Red dye.

    Science.gov (United States)

    Işik, Mustafa; Sponza, Delia Teresa

    2003-01-01

    In this study an anaerobic (upflow anaerobic sludge blanket reactor)/aerobic (completely stirred tank reactor) sequential system was used to treat a synthetic wastewater with minerals and co-substrate together with 100-4000 mg L(-1) of Congo Red dye (Direct red 28) (CR), which is a banned azo dye in Turkey. The effect of hydraulic retention time (HRT) on the decolorization and the COD removal efficiency was investigated at constant 100 mg L(-1) Congo Red concentration. 77% of COD and 95% of color was removed at a HRT of 0.486 days and a maximum organic loading rate of 6.656 kg COD m(-3) day(-1) in the anaerobic/aerobic stage. In the continuous operations, 88% of COD, 99% of color and 91% of total aromatic amine (TAA) were removed at a HRT of 3.60 days and at a CR concentration of 4000 mg L(-1). This corresponds to an organic loading rate of 1.81 kg COD m(-3) day(-1), and a CR dye loading rate of 46.37 g dye m(-3) h(-1), respectively, in the whole system. The TAA produced under anaerobic conditions was ultimately removed in the aerobic stage, resulting in very low aromatic amine recoveries (5-18%) in the last one. Therefore the aerobic effluents exhibited higher IC50 and specific methanogenic activities (SMA) compared to anaerobic and dye containing samples, indicating the reduced toxicity.

  14. Efficient production of (R-2-hydroxy-4-phenylbutyric acid by using a coupled reconstructed D-lactate dehydrogenase and formate dehydrogenase system.

    Directory of Open Access Journals (Sweden)

    Binbin Sheng

    Full Text Available (R-2-hydroxy-4-phenylbutyric acid [(R-HPBA] is a key precursor for the production of angiotensin-converting enzyme inhibitors. However, the product yield and concentration of reported (R-HPBA synthetic processes remain unsatisfactory.The Y52L/F299Y mutant of NAD-dependent D-lactate dehydrogenase (D-nLDH in Lactobacillus bulgaricus ATCC 11842 was found to have high bio-reduction activity toward 2-oxo-4-phenylbutyric acid (OPBA. The mutant D-nLDHY52L/F299Y was then coexpressed with formate dehydrogenase in Escherichia coli BL21 (DE3 to construct a novel biocatalyst E. coli DF. Thus, a novel bio-reduction process utilizing whole cells of E. coli DF as the biocatalyst and formate as the co-substrate for cofactor regeneration was developed for the production of (R-HPBA from OPBA. The biocatalysis conditions were then optimized.Under the optimum conditions, 73.4 mM OPBA was reduced to 71.8 mM (R-HPBA in 90 min. Given its high product enantiomeric excess (>99% and productivity (47.9 mM h(-1, the constructed coupling biocatalysis system is a promising alternative for (R-HPBA production.

  15. The effect of vinyl acetate in acetoclastic methanogenesis.

    Science.gov (United States)

    Durán, U; Gómez, J; Monroy, O; Ramírez, F

    2011-01-01

    The influence of vinyl acetate (VA) in the methanogenesis was evaluated, by using an upflow anaerobic sludge blanket reactor of 1.5L. The reactor was operated at 33.5 g/L volatile suspended solids to 30±2 °C, a hydraulic residence time of 1 day, an organic loading rate of 1 kgCOD/m3/d of two different mixtures of VA and glucose. The VA was methanized to 81% when its proportion was of 10% into reactor loading rate, when VA proportion increased to 25%, the methane production rate decreased to 62% and the acetate production rate increased almost 8 times. These results indicated that VA was only hydrolyzed and glucose was not used as a co-substrate. The effect of glucose on VA methanogenic degradation was evaluated through batch reactors of 60 mL, concluding that the glucose supported the methanogenesis without favoring the VA elimination. On the other hand, the results of the sludge from the reactor in the presence of VA demonstrated that VA caused an irreversibly inhibition of acetoclastic methanogenesis when the anaerobic sludge was exposed to this compound.

  16. UV photolysis for accelerating pyridine biodegradation.

    Science.gov (United States)

    Zhang, Yongming; Chang, Ling; Yan, Ning; Tang, Yingxia; Liu, Rui; Rittmann, Bruce E

    2014-01-01

    Pyridine, a nitrogen-containing heterocyclic compound, is slowly biodegradable, and coupling biodegradation with UV photolysis is a potential means to accelerate its biotransformation and mineralization. The initial steps of pyridine biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. We employed an internal circulation baffled biofilm reactor for pyridine biodegradation following three protocols: direct biodegradation (B), biodegradation after photolysis (P+B), and biodegradation with succinic acid added (B+S). Succinic acid was the main UV-photolysis product from pyridine, and its catabolic oxidation generates internal electron carriers that may accelerate the initial steps of pyridine biodegradation. Compared with direct biodegradation of pyridine (B), the removal rate for the same concentration of photolyzed pyridine (P+B) was higher by 15 to 43%, depending on the initial pyridine concentrations (increasing through the range of 130 to 310 mg/L). Adding succinic acid alone (B+S) gave results similar to P+B, which supports that succinic acid was the main agent for accelerating the pyridine biodegradation rate. In addition, protocols P+B and B+S were similar in terms of increasing pyridine mineralization over 10 h: 84% and 87%, respectively, which were higher than with protocol B (72%). The positive impact of succinic acid-whether added directly or produced via UV photolysis-confirms that its catabolism, which produced intracellular electron carriers, accelerated the initial steps of pyridine biotransformation.

  17. Ammonia-LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process.

    Science.gov (United States)

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2016-06-01

    In the current study it has been hypothesized that, when organic loading of an anaerobic reactor is increased, the additional cell biomass biosynthesis would capture more ammonia nitrogen and thereby reduce the ammonia toxicity. Therefore, the alleviation of the toxicity of high ammonia levels using lipids (glycerol trioleate-GTO) or carbohydrates (glucose-GLU) as co-substrates in manure-based thermophilic continuous stirred-tank reactors (R(GTO) and R(GLU), respectively) was tested. At 5gNH4(+)-NL(-1), relative methane production of R(GTO) and R(GLU), was 10.5% and 41% compared to the expected uninhibited production, respectively. At the same time control reactor (R(CTL)), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an "ammonia-LCFA (long chain fatty acids) synergetic co-inhibition" effect. Moreover, co-digestion with glucose in R(GLU) was more robust to ammonia toxicity compared to R(CTL). Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Utilization of Biodiesel By-Products for Biogas Production

    Directory of Open Access Journals (Sweden)

    Nina Kolesárová

    2011-01-01

    Full Text Available This contribution reviews the possibility of using the by-products from biodiesel production as substrates for anaerobic digestion and production of biogas. The process of biodiesel production is predominantly carried out by catalyzed transesterification. Besides desired methylesters, this reaction provides also few other products, including crude glycerol, oil-pressed cakes, and washing water. Crude glycerol or g-phase is heavier separate liquid phase, composed mainly by glycerol. A couple of studies have demonstrated the possibility of biogas production, using g-phase as a single substrate, and it has also shown a great potential as a cosubstrate by anaerobic treatment of different types of organic waste or energy crops. Oil cakes or oil meals are solid residues obtained after oil extraction from the seeds. Another possible by-product is the washing water from raw biodiesel purification, which is an oily and soapy liquid. All of these materials have been suggested as feasible substrates for anaerobic degradation, although some issues and inhibitory factors have to be considered.

  19. Anaerobic co-digestion of municipal organic wastes and pre-treatment to enhance biogas production from waste.

    Science.gov (United States)

    Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

    2014-01-01

    Co-digestion and pre-treatment have been recognized as effective, low-cost and commercially viable approaches to reduce anaerobic digestion process limitations and improve biogas yields. In our previous batch-scale study, fat, oil, and grease (FOG) was investigated as a suitable potential co-substrate, and thermo-chemical pre-treatment (TCPT) at pH = 10 and 55 °C improved CH4 production from FOG co-digestions. In this project, co-digestions with FOG were studied in bench-scale two-stage thermophilic semi-continuous flow co-digesters with suitable TCPT (pH = 10, 55 °C). Overall, a 25.14 ± 2.14 L/d (70.2 ± 1.4% CH4) biogas production was obtained, which was higher than in the two-stage system without pre-treatment. The results could provide valuable fundamental information to support full-scale investigations of anaerobic co-digestion of municipal organic wastes.

  20. Crystallization of prostaglandin-H synthase for X-ray structure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jahnke, K.; Degen, G.H.; Buehner, M. (Univ. of Wuerzburg (West Germany))

    1990-08-01

    Prostaglandin-H (PGH) synthase from ram seminal vesicles is a dimeric integral membrane protein of molecular weight 140 kDa. PGH synthase is a key enzyme in the biosynthesis of prostaglandins, has cyclooxygenase and peroxidase activities, and contains heme as a coenzyme. In the peroxidation step of its reaction, PGH synthase can use xenobiotics as co-substrates and can catalyze the metabolic activation of carcinogens such as diethylstilbestrol. To gain a detailed understanding of the inner workings of PGH synthase, the authors are investigating its three-dimensional structure by X-ray crystallography. A purification procedure was established that yields stable homogeneous PGH synthase that is at least 80% holoenzyme. Manipulation of these crystals is very difficult due to the small volume of the growth phase. The crystals dissolved rapidly in all aqueous media into which they were transferred for mounting in X-ray capillaries. Therefore, the authors have not yet been able to demonstrate their true X-ray scattering power. A crystal provisionally dry mounted diffracted to about 8 {angstrom} resolution.

  1. Production and Peripheral Roles of 5-HTP, a Precursor of Serotonin

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakamura

    2009-01-01

    Full Text Available Serotonin (5-hydroxytryptamine [5-HT] has been implicated in a variety of physiological and pathological functions. Multiple steps of enzyme reactions enable biosynthesis of 5-HT. The first and rate-limiting step of the reaction is the synthesis of 5-hydroxy-L-tryptophan (5-HTP from L-tryptophan. This step is dictated by an enzyme, tryptophan hydroxylase (TPH. TPH requires 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4 as a co-substrate of TPH. 5-HTP has been simply regarded as a precursor of 5-HT and it is believed that the biological significance of 5-HTP is essentially ascribed to the production of 5-HT. However, recent works shed light on the specific functions of 5-HTP in the periphery. In this review article, we focus on the specific roles of exogenous 5-HTP as well as the endogenous 5-HTP in the gut epithelial cells. Since systemic treatment with 5-HTP is applied to patients with lower 5-HT levels, the studies on the specific role of 5-HTP might create an opportunity to explore the effects of exogenously-applied 5-HTP in the gut in man.

  2. Methane emissions from digestate at an agricultural biogas plant.

    Science.gov (United States)

    Baldé, Hambaliou; VanderZaag, Andrew C; Burtt, Stephen D; Wagner-Riddle, Claudia; Crolla, Anna; Desjardins, Raymond L; MacDonald, Douglas J

    2016-09-01

    Methane (CH4) emissions were measured over two years at an earthen storage containing digestate from a mesophilic biodigester in Ontario, Canada. The digester processed dairy manure and co-substrates from the food industry, and destroyed 62% of the influent volatile solids (VS). Annual average emissions were 19gCH4m(-3)d(-1) and 0.27gCH4kg(-1)VSd(-1). About 76% of annual emissions occurred from June to October. Annual cumulative emissions from digestate corresponded to 12% of the CH4 produced within the digester. A key contributor to CH4 emissions was the sludge layer in storage, which contained as much VS as the annual discharge from the digester. These findings suggest that digestate management provides an opportunity to further enhance the benefits of biogas (i.e. reducing CH4 emissions compared to undigested liquid manure, and producing renewable energy). Potential best practices for future study include complete storage emptying, solid-liquid separation, and storage covering.

  3. SAFIRA. Sub-project B 1.3: Development of coupled in-situ reactors and optimisation of the geochemical processes in the discharge of different in situ reactor sytems. Final report; SAFIRA. Teilprojekt B 1.3: Entwicklung von gekoppelten in situ-Reaktoren und Optimierung der geochemischen Prozesse im Abstrom von verschiedenen in situ-Reaktor-Systemen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dahmke, A.; Schaefer, D.; Koeber, R.; Plagentz, V.

    2002-12-01

    langfristig kostenguenstige passive Massnahmen wie reaktive Barrieren zur Sanierung in Frage. Grundwasser, das mit mehreren und unterschiedlich reagierenden Stoffen kontaminiert ist, kann jedoch nicht mit Hilfe eines einzelnen reaktiven Materials gereinigt werden, daher wurde die Effektivitaet von Kombinationen unterschiedlicher reaktiver Materialien zur Sanierung untersucht. Von den untersuchten Kombinationen erwies sich die Hintereinanderschaltung von reduzierendem Eisen und Aktivkohle als besonders effektiv. Reduzierbare chlorierte Kohlenwasserstoffe werden im Eisen entfernt, die verbleibenden Kontaminanten adsorbieren auf der Aktivkohle. Auch die Hintereinanderschaltung von Eisen und Sauerstoff abgebenden ORC, in denen ein aerober mikrobieller Abbau statt findet, ist zur Entfernung von Mischkontaminationen geeignet. Eine Kostenschaetzung zeigt, dass die Kombination von Eisen und Aktivkohle in Abhaengigkeit von der Zusammensetzung der Kontamination guenstiger als Aktivkohle allein sein kann und generell guenstiger als die Kombination von Eisen und ORC ist. Ohne ein guenstigeres Verfahren zum Einbringen von Sauerstoff in den Aquifer wird die Hintereinanderschaltung von Eisen und Aktivkohle zur Sanierung von Mischkontaminationen empfohlen. Im direkten Abstrom von reaktiven Eisenbarrieren (auch in Kombination mit Aktivkohle) sind die Grenzwerte fuer Fe(II) und pH entsprechend der Trinkwasserverordnung ueberschritten. Im Abstrom von ORC-Reaktoren werden die zulaessigen Werte fuer Mg und pH ueberschritten. Untersuchungen im Abstrom dieser reaktiven Materialien zeigen, dass die hohen pH-Werte durch den Kontakt mit dem Aquifermaterial auf Aquifer-typische Werte gepuffert werden, die ueblicherweise unter den Grenzwerten der Trinkwasserverordnung liegen. Mit Erschoepfen der Pufferkapazitaet des Bodens breitet sich jedoch eine Zone mit erhoehtem pH-Wert im Aquifer aus. Die Geschwindigkeit dieser Ausbreitung haengt vom pH-Wert und dem Aquifermaterial ab. Gerade fuer sehr Organik

  4. Identification of hardly biodegradable residuals (sulfur- and nitrogen-containing substances) during waste water treatment, including the development of analytical methods; Identifizierung von schwer abbaubaren Reststoffen (stickstoff- und schwefelhaltigen Verbindungen) bei der Abwasserbehandlung, einschliesslich analytischer Methodenentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Moehle, E.; Huber, A.; Metzger, J.W.

    1999-07-01

    Eliminierbarkeit (Adsorption, Abbau) einiger der identifizierten Verbindungen im Belebtschlammverfahren zu erhalten, wurden erstmalig Abbauversuche im {mu}g/l-Bereich on-line mit HPLC-MS-MS unter aeroben Bedingungen durchgefuehrt. (orig.)

  5. Identification of hardly biodegradable residuals (sulfur- and nitrogen-containing substances) during waste water treatment, including the development of analytical methods; Identifizierung von schwer abbaubaren Reststoffen (stickstoff- und schwefelhaltigen Verbindungen) bei der Abwasserbehandlung, einschliesslich analytischer Methodenentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Moehle, E.; Huber, A.; Metzger, J.W.

    1999-07-01

    Eliminierbarkeit (Adsorption, Abbau) einiger der identifizierten Verbindungen im Belebt

  6. Effects of ferric hydroxid sludge dosage on sludge treatment/-disposal. Final report; Einfluesse einer Eisenschlammzugabe auf die Klaerschlammbehandlung/-entsorgung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, E.; Benzinger, S.

    1997-12-01

    Ueberschussschlamm mit Faellschlammanteilen (PRS+UeSS) gemeinsam behandelt. Eine Strasse wurde mit verschiedenen ES-Dosierungen beschickt. Die zweite Strasse diente zu Referenzzwecken. Bei der gemeinsamen Eindickung konnte zumeist eine Verbesserung der Ueberstandswasserqualitaet bezueglich der Parameter AFS, CSB und P durch die ES-Zugabe festgestellt werden. Gleichfalls wurden hoehere Feststoffgehalte nach der Eindickung erzielt. Bei der UeSS{sub BIO-P} Eindickung wurde zusaetzlich 45-70% P fixiert. Schwefelwasserstoffbedingte Schwimmschlammbildung konnte z.T. voellig unterbunden werden. Die gemeinsame Ausfaulung, sowohl mit UeSS{sub BIO-P} als auch mit PRS+UeSS wurde nicht negativ beeinflusst. Bei ES-Dosierungen >30 g Fe/kg TR{sub KS} war ein verbesserter oTR-Abbau festzustellen. Schwefelwasserstoff wurde, soweit vorhanden, deutlich reduziert; der Methangehalt des Faulgases wurde erhoeht. Rueckgeloestes Polyphosphat konnte fast vollstaendig refixiert werden. Die ES-Zugabe wirkte sich nur in geringem Masse auf das Entwaesserungverhalten aus. Dies gilt fuer die anorganische Konditionierung genauso, wie fuer die Konditionierung mit organischen FHM. Die Entsorgungsmoeglichkeiten wurden durch die ES-Dosierung nicht eingeschraenkt. Aus den Teilergebnissen der gemeinsamen Eindickung, Faulung Entwaesserung mit UeSS{sub BIO-P} laesst sich eine Abnahme der P-Rueckbelastung infolge Schlammwasserrueckfuehrung von 16,8% (bezogen auf P{sub ges} im Zulauf) in der Referenzanlage auf 11,2 bzw, 1,4% in Abhaengigkeit von der Eisendosierung errechnen. (orig.)

  7. SAFIRA. Sub-project B 1.3: Development of coupled in-situ reactors and optimisation of the geochemical processes in the discharge of different in situ reactor sytems. Final report; SAFIRA. Teilprojekt B 1.3: Entwicklung von gekoppelten in situ-Reaktoren und Optimierung der geochemischen Prozesse im Abstrom von verschiedenen in situ-Reaktor-Systemen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dahmke, A.; Schaefer, D.; Koeber, R.; Plagentz, V.

    2002-12-01

    langfristig kostenguenstige passive Massnahmen wie reaktive Barrieren zur Sanierung in Frage. Grundwasser, das mit mehreren und unterschiedlich reagierenden Stoffen kontaminiert ist, kann jedoch nicht mit Hilfe eines einzelnen reaktiven Materials gereinigt werden, daher wurde die Effektivitaet von Kombinationen unterschiedlicher reaktiver Materialien zur Sanierung untersucht. Von den untersuchten Kombinationen erwies sich die Hintereinanderschaltung von reduzierendem Eisen und Aktivkohle als besonders effektiv. Reduzierbare chlorierte Kohlenwasserstoffe werden im Eisen entfernt, die verbleibenden Kontaminanten adsorbieren auf der Aktivkohle. Auch die Hintereinanderschaltung von Eisen und Sauerstoff abgebenden ORC, in denen ein aerober mikrobieller Abbau statt findet, ist zur Entfernung von Mischkontaminationen geeignet. Eine Kostenschaetzung zeigt, dass die Kombination von Eisen und Aktivkohle in Abhaengigkeit von der Zusammensetzung der Kontamination guenstiger als Aktivkohle allein sein kann und generell guenstiger als die Kombination von Eisen und ORC ist. Ohne ein guenstigeres Verfahren zum Einbringen von Sauerstoff in den Aquifer wird die Hintereinanderschaltung von Eisen und Aktivkohle zur Sanierung von Mischkontaminationen empfohlen. Im direkten Abstrom von reaktiven Eisenbarrieren (auch in Kombination mit Aktivkohle) sind die Grenzwerte fuer Fe(II) und pH entsprechend der Trinkwasserverordnung ueberschritten. Im Abstrom von ORC-Reaktoren werden die zulaessigen Werte fuer Mg und pH ueberschritten. Untersuchungen im Abstrom dieser reaktiven Materialien zeigen, dass die hohen pH-Werte durch den Kontakt mit dem Aquifermaterial auf Aquifer-typische Werte gepuffert werden, die ueblicherweise unter den Grenzwerten der Trinkwasserverordnung liegen. Mit Erschoepfen der Pufferkapazitaet des Bodens breitet sich jedoch eine Zone mit erhoehtem pH-Wert im Aquifer aus. Die Geschwindigkeit dieser Ausbreitung haengt vom pH-Wert und dem Aquifermaterial ab. Gerade fuer sehr Organik

  8. 甘油和木糖共发酵生产1,3-丙二醇的研究%1,3-Propanediol production via cofermentation of glycerol and xylose

    Institute of Scientific and Technical Information of China (English)

    陈琳; 王领民; 金平; 凌凤香

    2013-01-01

    以克雷伯氏肺炎杆菌代谢甘油为研究对象,采用木糖作为发酵过程中的辅助底物与甘油共发酵生产1,3-丙二醇,以解决甘油单耗过大的问题,并研究了甘油和木糖共发酵过程中相关代谢物浓度的变化规律.实验表明:克雷伯氏肺炎杆菌可利用D-木糖经过磷酸戊糖途径为菌体代谢提供大量的还原力(NADPH和NADH),促进1,3-丙二醇的合成.与甘油单独发酵相比,以木糖作为辅助底物的微氧批次补料发酵中,1,3-丙二醇的质量浓度、甘油转化率及产量分别提高了10.58%,21.11%和10.98%.共发酵生产1,3-丙二醇在降低甘油到1,3-丙二醇单耗的同时,还可以促进副产物的生成,为克雷伯氏菌发酵多联产工艺提供了可能,从而较全面地降低甘油发酵生产1,3-丙二醇工艺的技术成本,具有一定的研究意义.%Taking fermentation of glycerol by Klebsiella pneumoniae as research subject,1,3-propanediol (PD) was produced by cofermentation of glycerol and xylose (as cosubstrate) so as to solve the problem of high glycerol consumption.The changes of relevant metabolites concentration in the cofermentation of glycerol and xylose were also studied.The experimental results show that the synthesis of 1,3-propanediol can be enhanced through the pentose phosphate pathways of D-xylose by Klebsiella pneumoniae,offering more reducing equivalent (NAPDH and NADH).Compared with the fermentation of glycerol alone,in fed-batch fermentation with xylose as cosubstrate,the final 1,3-PD mass concentration,conversion rate of glycerol and output are improved by 10.58%,21.11%and 10.98%,respectively.The glycerol consumption decreases during the cofermentation of glycerol and xylose to produce 1,3-propylene,which can also promote the formation of by-products,allowing a possibility that polygeneration process can be achieved by Klebsiella fermentation,thus reducing comprehensively the cost of 1,3-propanediol production by glycerol

  9. Uso de carvão ativado e resina de troca iônica para limpeza e concentração de enzimas em extratos de madeira biodegradada = Use of activated charcoal and ion-exchange resin to cleaN up and concentrate enzymes in extracts from biodegraded wood

    Directory of Open Access Journals (Sweden)

    André Ferraz

    2010-10-01

    Full Text Available Ceriporiopsis subvermispora foi utilizado para a biodegradação de cavacos de Eucalyptus grandis na presença ou ausência de cossubstratos (glicose e milhocina durante 7, 14 e 28 dias. Os cavacos obtidos em cada um desses períodos foram extraídos com tampãoacetato de sódio 50 mM (pH 5,5 adicionado de 0,01% de Tween 60. A atividade de manganês peroxidases (MnPs nos extratos foi marcante ao longo de todo o período de biodegradação, tanto na ausência (430, 765 e 896 UI kg-1, respectivamente quanto na presença de cossubstratos (1.013, 2.066 e 2.323 UI kg-1, respectivamente. Os extratos apresentaram elevadas relações entre absorbância a 280 e a 405 nm, indicando forte abundância de compostos aromáticos derivados da lignina em relação à heme-peroxidases. A adsorção em carvão ativado se mostrou uma estratégia adequada para reduzir a absorbância a280 nm em todos os extratos. Além disso, permitiu maximizar a capacidade de um leito de resina trocadora de ânions (DEAE Sepharose, utilizado para concentrar as MnPs presentes nos referidos extratos. Concluiu-se que o uso de carvão ativado seguido de adsorção em DEAE Sepharose é uma estratégia que pode ser utilizada para concentrar MnPs em extratos obtidos durante a biodegradação de E. grandis por C. subvermispora.Ceriporiopsis subvermispora was used for the biodegradation of Eucalyptus grandis chips in the presence or absence of cosubstrates(glucose and corn steep liquor during 7, 14 and 28 days. Afterwards, the biodegraded chips were extracted with 50 mM sodium acetate buffer (pH 5.5 supplemented with 0.01% Tween 60. High activities of manganese peroxidases (MnPs were observed in all the extracts, both in the absence (430, 765 and 896 UI kg-1, respectively and in the presence of co-substrates (1,013; 2,066 and 2,323 UI kg-1, respectively. The extracts presented a high ratio between absorbances at 280 and 405 nm, indicating a strong abundance of aromatic compounds derived from

  10. 一株菲降解菌的生长特性及其对荧蒽和芘的降解能力%The Growth Characteristics and Fluoranthene and Pyrene Degradation Potential of a Phenanthrene-degrading Strain

    Institute of Scientific and Technical Information of China (English)

    杨秀虹; 汤婉环; 李适宇

    2012-01-01

    The effects of different culture conditions including temperature, pH, initial phenanthrene concentration and co-substrates on the growth of a phenanthrene-degrading strain PE1501-1 affiliated to the genus Azospirillum were studied. The potential degradation of fluoranthene and pyrene by strain PE1501-1 in liquid culture medium or soil microcosm were investigated. The strain shows better growth under slightly acid culture conditions. Optimal temperature and pH are as 30 ℃ and 5. 0 respectively in a mineral salts liquid medium with phenanthrene at 50 mg/L as the sole substrate. The strain is able to tolerate higher initial phenanthrene concentration than 200 mg/L, while an obvious lag phase is observed when the strain is exposed to high initial phenanthrene concentration. The growth of strain PE1501-1 is transitorily enhanced by the individual addition of acetic acid, dissolved fulvic acid or dissolved humic acid as the co-substrate of phenanthrene. Strain PE1501-1 is able to grow in liquid culture media by utilizing phenanthrene or fluorenthene as the sole carbon and energy source with the potential to degrade flu-orenthene but not pyrene. The removal of phenanthrene, fluorenthene or pyrene is enhanced by adding strain PE 1501-1 in sterile soils.%研究了一株固氮螺菌属(Azospirillum)的菲降解菌PE1501-1在不同培养条件(温度、初始pH值、菲初始浓度、共基质)下的生长特性,并初步考察了该菌株在液体培养基和土壤中对4环PAHs-荧蒽和芘的潜在降解能力.结果表明,在含菲50 mg/L的无机盐液体培养基中,该菌株的最适生长温度为30C;偏酸性环境更有利于菌株生长,液体培养基初始pH5.0时菌株生长最好;该菌株能耐受菲的初始浓度超过200 mg/L,但菲初始浓度较高时菌株生长出现较明显的延迟期;添加乙酸、溶解性富里酸或溶解性胡敏酸作为菲的共基质对菌株生长有短暂的促进作用;在液体培养基中菌株能以菲

  11. Insights into Nitrate-Reducing Fe(II) Oxidation Mechanisms through Analysis of Cell-Mineral Associations, Cell Encrustation, and Mineralogy in the Chemolithoautotrophic Enrichment Culture KS.

    Science.gov (United States)

    Nordhoff, M; Tominski, C; Halama, M; Byrne, J M; Obst, M; Kleindienst, S; Behrens, S; Kappler, A

    2017-07-01

    Most described nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOB) are mixotrophic and depend on organic cosubstrates for growth. Encrustation of cells in Fe(III) minerals has been observed for mixotrophic NRFeOB but not for autotrophic phototrophic and microaerophilic Fe(II) oxidizers. So far, little is known about cell-mineral associations in the few existing autotrophic NRFeOB. Here, we investigate whether the designated autotrophic Fe(II)-oxidizing strain (closely related to Gallionella and Sideroxydans) or the heterotrophic nitrate reducers that are present in the autotrophic nitrate-reducing Fe(II)-oxidizing enrichment culture KS form mineral crusts during Fe(II) oxidation under autotrophic and mixotrophic conditions. In the mixed culture, we found no significant encrustation of any of the cells both during autotrophic oxidation of 8 to 10 mM Fe(II) coupled to nitrate reduction and during cultivation under mixotrophic conditions with 8 to 10 mM Fe(II), 5 mM acetate, and 4 mM nitrate, where higher numbers of heterotrophic nitrate reducers were present. Two pure cultures of heterotrophic nitrate reducers (Nocardioides and Rhodanobacter) isolated from culture KS were analyzed under mixotrophic growth conditions. We found green rust formation, no cell encrustation, and only a few mineral particles on some cell surfaces with 5 mM Fe(II) and some encrustation with 10 mM Fe(II). Our findings suggest that enzymatic, autotrophic Fe(II) oxidation coupled to nitrate reduction forms poorly crystalline Fe(III) oxyhydroxides and proceeds without cellular encrustation while indirect Fe(II) oxidation via heterotrophic nitrate-reduction-derived nitrite can lead to green rust as an intermediate mineral and significant cell encrustation. The extent of encrustation caused by indirect Fe(II) oxidation by reactive nitrogen species depends on Fe(II) concentrations and is probably negligible under environmental conditions in most habitats.IMPORTANCE Most described nitrate

  12. 离子液体/缓冲液两相体系中热带假丝酵母不对称还原制备(S)-1-[3,5-双(三氟甲基)苯基]乙醇%Asymmetric Synthesis of (S)-1-[3,5-Bis(trifluoromyl)phenyl]Ethanol in Biphasic Ionic Liquid / Water Systems with Candida tropicalis cells

    Institute of Scientific and Technical Information of China (English)

    王普; 苏会贞; 何军邀; 黄敏敏

    2012-01-01

    An ionic liquid-buffer biphasic system was employed to improve the asymmetric reduction of 3,5-bis(trifluoromethyl) acetophenone to (S)-1-[3,5-bis(trifluoromethyl)phenyl] ethanol catalyzed by Candida tropicalis 104 cells. Some key reaction parameters, such as [BMIM]PF6 content, co-substrate and its concentration, substrate concentration, cell concentration and reaction time, were investigated, respectively. The results show that these factors obviously affect the yield of the prepared product, but the optical purity of the corresponding (5)-1-[3,5-bis(trifluoromethyl)phenyl] ethanol keep intact. The optimum values of [BMIM]PF6 content, co-substrate concentration, substrate concentration, cell concentration and reaction time are 5 %, 60 g·L-1 (isopropanol), 70 mmol·L-1, 350 g·L-1 and 24 h, respectively. Under above optimal conditions, the best yield of 82.5 % and over 99.9 % of product e.e. were obtained. The results also demonstrate that the byconversion is more efficient in [BMIM]PFe/buffer biphasic systems than that in monophasic aqueous system, the substrate concentration and the yield can be markedly increased, and the reaction time is shorter for 6 h.%研究了1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF6/缓冲液两相体系中,热带假丝酵母104细胞催化3,5-双三氟甲基苯乙酮不对称还原制备(S)-1-[3,5-双(三氟甲基)苯基]乙醇的反应过程.通过考察影响生物还原反应的主要因素,如离子液体浓度、辅助底物种类和浓度、底物浓度、菌体浓度和转化时间等,发现上述因素对产率影响较大,但基本不影响产物手性醇的光学纯度.优化得到的较佳还原反应条件为:[BMIM]PF6体积分数5%,辅助底物为60 g·L-1异丙醇,底物3,5-双三氟甲基苯乙酮浓度70 mmol·L-1,菌体浓度350 g·L-1,转化时间24 h.在优化条件下,产率达82.5%,产物(S)-1-[3,5-双(三氟甲基)苯基]乙醇的对映体过量值大于99.9%.与水相转化相比,采用[BMIM]PF6/

  13. Effect of carbon/nitrogen ratio on anaerobic co-digestion of swine manure with model stalk wastes%典型秸秆废弃物与猪粪共发酵过程碳氮比的影响研究

    Institute of Scientific and Technical Information of China (English)

    成喜雨; 李强; 王静; 钟成

    2014-01-01

    研究了碳氮比对秸秆猪粪共消化的影响.与棉秆相比,木质素含量较低的玉米秆产气速率和沼气产率更高.通过秸秆猪粪共消化,产气速率和沼气产率都得到了显著提高.碳氮比为15时,延滞期较长;碳氮比为20~25时,产气速率得到提高,沼气产率也相对较高;碳氮比提高到30时,产气高峰来的最早,但沼气产率降低.玉米秆和棉秆与猪粪共消化最佳碳氮比为25,最高沼气产率分别达397 ml/g和289 ml/g,为对照产量的128%和180%.通过调节混合物比例使之达到优选的碳氮比是指导共消化操作的方法.%China produced a number of stalk wastes and their total yield reached 0.7 billion tons per year.Anaerobic digestion provided a viable alternative for the disposal of those stalk wastes.When considering their high carbon content,stalk waste may also be used as potential co-substrates of anaerobic digestion of swine manure.Although co-digestion of manure wastes with many crop residues was frequently studied,the optimal mixing ratios of co-substrates obtained in different studies were different.And the mechanism on the improvement of process performance by using co-digestion was not well understood.In the present,effect of carbon/nitrogen (C/N) ratio on co-digestion of swine manure (SM) with stalk wastes was studied.Higher daily biogas production and biogas yield was recorded from digestion of corn stalk than those in the cotton stalk with higher lignin content.In co-digestion of SM with stalk wastes,a longer lag phase were observed at a C/N of 15,while the performance in terms of biogas production rate and yield was enhanced at C/N of 20~25.At a higher C/N of 30,daily biogas production peaked earlier,but lower biogas yield was obtained.During co-digestion of SM with corn and cotton stalk,a C/N ratio of 25 was found to be the best and the highest biogas yields reached 397 and 289 mL/g TS,which were 128% and 180% of those in the control

  14. Co-fermentation of organic waste with farming waste and/or sewage sludge; Kovergaerung von Bioabfaellen mit landwirtschaftlichen Abfaellen bzw. Klaerschlaemmen

    Energy Technology Data Exchange (ETDEWEB)

    Braukmeier, J.; Stegmann, R. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abfallwirtschaft und Stadttechnik

    1998-10-01

    Co-fermentation of additional substrates with liquid manure, organic waste or sewage sludge enhances the economy of biogas plants by generating additional income and increasing biogas production. Often, it is only thanks to co-fermentation that a plant can at all be operated (for instance, plants processing liquid manure). Technical problems that may be caused by some of the additional substrates can be solved by further conditioning equipment and an extended measuring program. The economic efficiency of such investments results primarily from the envisaged throughput. The hygienization of the co-substrates permits both compliance with the regulations governing the disposal of animal carcasses and enhances acceptance in the farming sector, which buys the fermentation product. On the whole, methane fermentation of organic waste is recommendable in the light of the `Kreislaufwirtschaftsgesetz` as it harnesses existing material and energy resources and as the product cycle is closed by the use of the product in farming. (orig.) [Deutsch] Die Mitbehandlung von zusaetzlichen Substraten in Guelle, Bioabfall- oder Klaerschlamm-Faulungsanlagen ermoeglicht durch (zusaetzliche) Einnahmen und eine erhoehte Gasproduktion einen wirtschaftlicheren Betrieb von Biogasanlagen. Oft wird durch Kofermentation ein Betrieb ueberhaupt erst moeglich (z.B. Guellenanlagen). Die technischen Probleme, die durch einige der zusaetzlichen Substrate auftreten koennen, sind durch Zusatzeinrichtungen zur Aufbereitung und ein erweitertes Messprogramm loesbar. Die Wirtschaftlichkeit derartiger Investitionen ergibt sich in erster Linie aus dem angestrebten Anlagendurchsatz. Durch die Hygienisierung der Kosubstrate koennen sowohl die Vorschriften des Tierkoerperbeseitigungs-Gesetzes eingehalten als auch eine Akzeptanzsteigerung bei den das Gaerprodukt abnehmenden Landwirten erreicht werden. Insgesamt gesehen, ist die Methangaerung von organischen Abaellen nach dem Kreislaufwirtschaftsgesetz anzustreben

  15. Increasing anaerobic acetate consumption and ethanol yields in Saccharomyces cerevisiae with NADPH-specific alcohol dehydrogenase.

    Science.gov (United States)

    Henningsen, Brooks M; Hon, Shuen; Covalla, Sean F; Sonu, Carolina; Argyros, D Aaron; Barrett, Trisha F; Wiswall, Erin; Froehlich, Allan C; Zelle, Rintze M

    2015-12-01

    Saccharomyces cerevisiae has recently been engineered to use acetate, a primary inhibitor in lignocellulosic hydrolysates, as a cosubstrate during anaerobic ethanolic fermentation. However, the original metabolic pathway devised to convert acetate to ethanol uses NADH-specific acetylating acetaldehyde dehydrogenase and alcohol dehydrogenase and quickly becomes constrained by limited NADH availability, even when glycerol formation is abolished. We present alcohol dehydrogenase as a novel target for anaerobic redox engineering of S. cerevisiae. Introduction of an NADPH-specific alcohol dehydrogenase (NADPH-ADH) not only reduces the NADH demand of the acetate-to-ethanol pathway but also allows the cell to effectively exchange NADPH for NADH during sugar fermentation. Unlike NADH, NADPH can be freely generated under anoxic conditions, via the oxidative pentose phosphate pathway. We show that an industrial bioethanol strain engineered with the original pathway (expressing acetylating acetaldehyde dehydrogenase from Bifidobacterium adolescentis and with deletions of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2) consumed 1.9 g liter(-1) acetate during fermentation of 114 g liter(-1) glucose. Combined with a decrease in glycerol production from 4.0 to 0.1 g liter(-1), this increased the ethanol yield by 4% over that for the wild type. We provide evidence that acetate consumption in this strain is indeed limited by NADH availability. By introducing an NADPH-ADH from Entamoeba histolytica and with overexpression of ACS2 and ZWF1, we increased acetate consumption to 5.3 g liter(-1) and raised the ethanol yield to 7% above the wild-type level. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Revisiting the metabolism and physiological functions of caprylic acid (C8:0) with special focus on ghrelin octanoylation.

    Science.gov (United States)

    Lemarié, Fanny; Beauchamp, Erwan; Legrand, Philippe; Rioux, Vincent

    2016-01-01

    Caprylic acid (octanoic acid, C8:0) belongs to the class of medium-chain saturated fatty acids (MCFAs). Dairy products and specific oils like coconut oil are natural sources of dietary C8:0 but higher intakes of this fatty acid can be provided with MCT (Medium-Chain Triglycerides) oil that consists in 75% of C8:0. MCFAs have physical and metabolic properties that are distinct from those of long-chain saturated fatty acids (LCFAs ≥ 12 carbons). Beneficial physiological effects of dietary C8:0 have been studied for a long time and MCT oil has been used as a special energy source for patients suffering from pancreatic insufficiency, impaired lymphatic chylomicron transport and fat malabsorption. More recently, caprylic acid was also shown to acylate ghrelin, the only known peptide hormone with an orexigenic effect. Through its covalent binding to the ghrelin peptide, caprylic acid exhibits an emerging and specific role in modulating physiological functions themselves regulated by octanoylated ghrelin. Dietary caprylic acid is therefore now suspected to provide the ghrelin O-acyltransferase (GOAT) enzyme with octanoyl-CoA co-substrates necessary for the acyl modification of ghrelin. This review tries to highlight the discrepancy between the formerly described beneficial effects of dietary MCFAs on body weight loss and the C8:0 newly reported effect on appetite stimulation via ghrelin octanoylation. The subsequent aim of this review is to demonstrate the relevance of carrying out further studies to better understand the physiological functions of this particular fatty acid. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. Discovery and characterization of an F420-dependent glucose-6-phosphate dehydrogenase (Rh-FGD1) from Rhodococcus jostii RHA1.

    Science.gov (United States)

    Nguyen, Quoc-Thai; Trinco, Gianluca; Binda, Claudia; Mattevi, Andrea; Fraaije, Marco W

    2017-04-01

    Cofactor F420, a 5-deazaflavin involved in obligatory hydride transfer, is widely distributed among archaeal methanogens and actinomycetes. Owing to the low redox potential of the cofactor, F420-dependent enzymes play a pivotal role in central catabolic pathways and xenobiotic degradation processes in these organisms. A physiologically essential deazaflavoenzyme is the F420-dependent glucose-6-phosphate dehydrogenase (FGD), which catalyzes the reaction F420 + glucose-6-phosphate → F420H2 + 6-phospho-gluconolactone. Thereby, FGDs generate the reduced F420 cofactor required for numerous F420H2-dependent reductases, involved e.g., in the bioreductive activation of the antitubercular prodrugs pretomanid and delamanid. We report here the identification, production, and characterization of three FGDs from Rhodococcus jostii RHA1 (Rh-FGDs), being the first experimental evidence of F420-dependent enzymes in this bacterium. The crystal structure of Rh-FGD1 has also been determined at 1.5 Å resolution, showing a high similarity with FGD from Mycobacterium tuberculosis (Mtb) (Mtb-FGD1). The cofactor-binding pocket and active-site catalytic residues are largely conserved in Rh-FGD1 compared with Mtb-FGD1, except for an extremely flexible insertion region capping the active site at the C-terminal end of the TIM-barrel, which also markedly differs from other structurally related proteins. The role of the three positively charged residues (Lys197, Lys258, and Arg282) constituting the binding site of the substrate phosphate moiety was experimentally corroborated by means of mutagenesis study. The biochemical and structural data presented here provide the first step towards tailoring Rh-FGD1 into a more economical biocatalyst, e.g., an F420-dependent glucose dehydrogenase that requires a cheaper cosubstrate and can better match the demands for the growing applications of F420H2-dependent reductases in industry and bioremediation.

  18. Spectroscopic Evidence for the Two C-H-Cleaving Intermediates of Aspergillus nidulans Isopenicillin N Synthase.

    Science.gov (United States)

    Tamanaha, Esta; Zhang, Bo; Guo, Yisong; Chang, Wei-Chen; Barr, Eric W; Xing, Gang; St Clair, Jennifer; Ye, Shengfa; Neese, Frank; Bollinger, J Martin; Krebs, Carsten

    2016-07-20

    The enzyme isopenicillin N synthase (IPNS) installs the β-lactam and thiazolidine rings of the penicillin core into the linear tripeptide l-δ-aminoadipoyl-l-Cys-d-Val (ACV) on the pathways to a number of important antibacterial drugs. A classic set of enzymological and crystallographic studies by Baldwin and co-workers established that this overall four-electron oxidation occurs by a sequence of two oxidative cyclizations, with the β-lactam ring being installed first and the thiazolidine ring second. Each phase requires cleavage of an aliphatic C-H bond of the substrate: the pro-S-CCys,β-H bond for closure of the β-lactam ring, and the CVal,β-H bond for installation of the thiazolidine ring. IPNS uses a mononuclear non-heme-iron(II) cofactor and dioxygen as cosubstrate to cleave these C-H bonds and direct the ring closures. Despite the intense scrutiny to which the enzyme has been subjected, the identities of the oxidized iron intermediates that cleave the C-H bonds have been addressed only computationally; no experimental insight into their geometric or electronic structures has been reported. In this work, we have employed a combination of transient-state-kinetic and spectroscopic methods, together with the specifically deuterium-labeled substrates, A[d2-C]V and AC[d8-V], to identify both C-H-cleaving intermediates. The results show that they are high-spin Fe(III)-superoxo and high-spin Fe(IV)-oxo complexes, respectively, in agreement with published mechanistic proposals derived computationally from Baldwin's founding work.

  19. Purification, properties, and kinetic studies of cytoplasmic malate dehydrogenase from Taenia solium cysticerci.

    Science.gov (United States)

    Plancarte, Agustín; Nava, Gabriela; Mendoza-Hernández, Guillermo

    2009-07-01

    Malate dehydrogenase (L: -malate: NAD oxidoreductase, EC 1.1.1.37) from the cytoplasm of Taenia solium cysticerci (cMDHTs) was purified 48-fold through a four-step procedure involving salt fractionation, ionic exchange, and dye affinity chromatography. cMDHTs had a native M (r) of 64,000, while the corresponding value per subunit, obtained under denaturing conditions, was 32,000. The enzyme is partially positive, with an isoelectric point of 8.7, and had a specific activity of 2,615 U mg(-1) in the reduction of oxaloacetate. The second to the 21st amino acids from cMDHTs N-terminal group were P G P L R V L I T G A A G Q I A Y N L S. This sequence is 100% identical to that of Echinococcus granulosus. Basic kinetic parameters were determined for this enzyme. The optimum pH for enzyme reaction was at 7.6 for oxaloacetate reduction and at 9.6 for malate oxidation. K (m) values for oxaloacetate, malate, NAD, and NADH were 2.4, 215, 50, and 48 microM, respectively. V (max) values for the substrates and cosubstrates as described above were 1,490, 87.8, 104, and 1,714 micromol min(-1) mg(-1). Several NAD analogs, structurally altered in either the pyridine or purine moiety, were observed to function as coenzymes in the reaction catalyzed by the purified malate dehydrogenase. cMDHTs activity was uncompetitive inhibited by arsenate for both the forward (Ki = 8.2 mM) and reverse (Ki = 77 mM) reactions. The mechanism of the cMDHTs reactivity was investigated kinetically by the product inhibition approach. The results of this study are qualitatively consistent with an Ordered Bi Bi reaction mechanism, in which only the coenzymes can react with the free enzyme.

  20. Metal ions control product specificity of isoprenyl diphosphate synthases in the insect terpenoid pathway

    Science.gov (United States)

    Frick, Sindy; Nagel, Raimund; Schmidt, Axel; Bodemann, René R.; Rahfeld, Peter; Pauls, Gerhard; Brandt, Wolfgang; Gershenzon, Jonathan; Boland, Wilhelm; Burse, Antje

    2013-01-01

    Isoprenyl diphosphate synthases (IDSs) produce the ubiquitous branched-chain diphosphates of different lengths that are precursors of all major classes of terpenes. Typically, individual short-chain IDSs (scIDSs) make the C10, C15, and C20 isoprenyl diphosphates separately. Here, we report that the product length synthesized by a single scIDS shifts depending on the divalent metal cofactor present. This previously undescribed mechanism of carbon chain-length determination was discovered for a scIDS from juvenile horseradish leaf beetles, Phaedon cochleariae. The recombinant enzyme P. cochleariae isoprenyl diphosphate synthase 1 (PcIDS1) yields 96% C10-geranyl diphosphate (GDP) and only 4% C15-farnesyl diphosphate (FDP) in the presence of Co2+ or Mn2+ as a cofactor, whereas it yields only 18% C10 GDP but 82% C15 FDP in the presence of Mg2+. In reaction with Co2+, PcIDS1 has a Km of 11.6 μM for dimethylallyl diphosphate as a cosubstrate and 24.3 μM for GDP. However, with Mg2+, PcIDS1 has a Km of 1.18 μM for GDP, suggesting that this substrate is favored by the enzyme under such conditions. RNAi targeting PcIDS1 revealed the participation of this enzyme in the de novo synthesis of defensive monoterpenoids in the beetle larvae. As an FDP synthase, PcIDS1 could be associated with the formation of sesquiterpenes, such as juvenile hormones. Detection of Co2+, Mn2+, or Mg2+ in the beetle larvae suggests flux control into C10 vs. C15 isoprenoids could be accomplished by these ions in vivo. The dependence of product chain length of scIDSs on metal cofactor identity introduces an additional regulation for these branch point enzymes of terpene metabolism. PMID:23440195