Bioremediation of PAHs contaminated river sediment by an integrated approach with sequential injection of co-substrate and electron acceptor: Lab-scale study.

Science.gov (United States)

Liu, Tongzhou; Zhang, Zhen; Dong, Wenyi; Wu, Xiaojing; Wang, Hongjie

2017-11-01

In this study, the feasibility of employing an integrated bioremediation approach in contaminated river sediment was evaluated. Sequential addition of co-substrate (acetate) and electron acceptor (NO 3 - ) in a two-phase treatment was capable of effectively removing polycyclic aromatic hydrocarbons (PAHs) in river sediment. The residual concentration of total PAHs decreased to far below effect range low (ERL) value within 91 days of incubation, at which concentration it could rarely pose biological impairment. The biodegradation of high molecular weight PAHs were found to be mainly occurred in the sediment treated with co-substrates (i.e. acetate or methanol), in which acetate was found to be more suitable for PAHs degradation. The role of co-substrates in influencing PAHs biodegradation was tentatively discussed herein. Additionally, the sediment odorous problem and blackish appearance were intensively addressed by NO 3 - injection. The results of this study demonstrated that integrating two or more approaches/processes would be a helpful option in sediment remediation. It can lead to a more effective remediation performance, handle multiple contamination issues, as well as mitigate environmental risks caused by one of the single methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of simultaneously enzymatic fructo- and inulo-oligosaccharide production using co-substrates of sucrose and inulin from Jerusalem artichoke.

Science.gov (United States)

Kawee-Ai, Arthitaya; Ritthibut, Nuntinee; Manassa, Apisit; Moukamnerd, Churairat; Laokuldilok, Thunnop; Surawang, Suthat; Wangtueai, Sutee; Phimolsiripol, Yuthana; Regenstein, Joe M; Seesuriyachan, Phisit

2018-02-07

Prebiotic substances are extracted from various plant materials or enzymatic hydrolysis of different substrates. The production of fructo-oligosaccharide (FOS) and inulo-oligosaccharide (IOS) was performed by applying two substrates, sucrose and inulin; oligosaccharide yields were maximized using central composite design to evaluate the parameters influencing oligosaccharide production. Inulin from Jerusalem artichoke (5-15% w/v), sucrose (50-70% w/v), and inulinase from Aspergillus niger (2-7 U/g) were used as variable parameters for optimization. Based on our results, the application of sucrose and inulin as co-substrates for oligosaccharide production through inulinase hydrolysis and synthesis is viable in comparative to a method using a single substrate. Maximum yields (674.82 mg/g substrate) were obtained with 5.95% of inulin, 59.87% of sucrose, and 5.68 U/g of inulinase, with an incubation period of 9 hr. The use of sucrose and inulin as co-substrates in the reaction simultaneously produced FOS and IOS from sucrose and inulin. Total conversion yield was approximately 67%. Our results support the high value-added production of oligosaccharides using Jerusalem artichoke, which is generally used as a substrate in prebiotics and/or bioethanol production.

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

Identification of locally available structural material as co-substrate for organic waste composting in Tamil Nadu, India.

Science.gov (United States)

Springer, C; Heldt, N

2016-06-01

Owing to the lack in structural strength while composting certain kinds of organic wastes, 11 co-substrates were tested that are generally locally available in rural areas of northern Tamil Nadu, India. In addition to the classical composting parameters such as carbon/nitrogen ratio, moisture content, dry matter and organic dry matter, a compression test was conducted to evaluate the structural strength and the suitability as bulking agent for composting processes. Additionally, with respect to the climatic conditions in India, the water holding capacity was also evaluated. © The Author(s) 2016.

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

Optimization of the selection process of the co-substrates for chicken manure fermentation using neural modeling

Directory of Open Access Journals (Sweden)

Lewicki Andrzej

2016-01-01

Full Text Available Intense development of research equipment leads directly to increasing cognitive abilities. However, along with the raising amount of data generated, the development of the techniques allowing the analysis is also essential. Currently, one of the most dynamically developing branch of computer science and mathematics are the Artificial Neural Networks (ANN. Their main advantage is very high ability to solve the regression and approximation issues. This paper presents the possibility of application of artificial intelligence methods to optimize the selection of co-substrates intended for methane fermentation of chicken manure. 4-layer MLP network has proven to be the optimal structure modeling the obtained empirical data.

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.

Selection of Co-Substrate and Aeration Conditions for Vanillin Production by Escherichia coli JM109/pBB1

Directory of Open Access Journals (Sweden)

Paolo Torre

2004-01-01

Full Text Available Yeast extract, Luria-Bertani medium and tryptone were tested as co-substrates for vanillin production from ferulic acid by resting cells of Escherichia coli JM109/pBB1. Yeast extract proved to be the best component for sustaining such a bioconversion, which is not self-sustained from the bioenergetic point of view. Tests were also performed under variable aeration conditions by simultaneously varying the ratio of medium to vessel volume and the agitation speed. The results of these tests suggest that, under excess aeration, a non-specific oxidase activity was very likely responsible for the oxidation of a significant portion of vanillin to vanillic acid, thus reducing the vanillin yield.

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-01

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

Contaminated land and ground water: trends in the development of biological methods for remediation research; Altlasten und Grundwasser - Trends in der Entwicklung der biologischen Methoden in der Sanierungsforschung

Energy Technology Data Exchange (ETDEWEB)

Stottmeister, U [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Leipzig (Germany). Sektion Sanierungsforschung

1998-11-01

Future developments in environmental biotechnology and in situ-remediation processes need the understanding and the influencing of the interaction between all components of a biological biocoenosis, especially in biofilm. Better performances concerning the elimination of contaminants could be made possible by the balanced addition of both additional electron acceptors and cosubstrates, in which the studies of the physiological interaction must be studied. The application of physical methods like radio waves are able to support the microbiological processes. The understanding of the interaction between biotic and abiotic processes in contaminated sites is incomplete at the present time. Ecotechnical processes must decrease the time demand of the natural attenuation and remove inhibitions. Phytoremediation is promising; the understanding of the root - microorganism interaction is the basis of new applications. (orig.) [Deutsch] Die zukuenftigen Entwicklungen der Umweltbiotechnologie und der in situ-Sanierungsverfahren sollten durch das Erkennen und die Beeinflussung des Wechselspiels von Biozoenosen insbesondere in Biofilmen bestimmt werden. Leistungssteigerungen des Schadstoffabbaus sind moeglich durch die bilanzierte Zugabe zusaetzlicher Elektronenakzeptoren oder von Kosubstraten, deren physiologische Wirkungsweise erkannt werden muss. Physikalische Massnahmen wie z.B. die Radiowellenanwendung koennen mikrobiologische Prozesse unterstuetzen. Das Wechselspiel biotischer und abiotischer Prozesse in Altlasten ist erst unvollstaendig verstanden. Oekotechnische Prozesse muessen die natuerliche Selbstreinigung beschleunigen oder Inhibitionen aufheben. Die vielversprechenden Methoden der Phytoremediation werden neue Anwendungsgebiete finden, wenn die Wurzelraum-Mikroorganismen-Wechselwirkung verstanden wird. (orig.)

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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.)

Optimization of volatile fatty acid production with co-substrate of food wastes and dewatered excess sludge using response surface methodology.

Science.gov (United States)

Hong, Chen; Haiyun, Wu

2010-07-01

Central-composite design (CCD) and response surface methodology (RSM) were used to optimize the parameters of volatile fatty acid (VFA) production from food wastes and dewatered excess sludge in a semi-continuous process. The effects of four variables (food wastes composition in the co-substrate of food wastes and excess sludge, hydraulic retention time (HRT), organic loading rate (OLR), and pH) on acidogenesis were evaluated individually and interactively. The optimum condition derived via RSM was food wastes composition, 88.03%; HRT, 8.92 days; OLR, 8.31 g VSS/ld; and pH 6.99. The experimental VFA concentration was 29,099 mg/l under this optimum condition, which was well in agreement with the predicted value of 28,000 mg/l. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

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

Effect of increasing proportions of lignocellulosic cosubstrate on the single-phase and two-phase digestion of readily biodegradable substrate

International Nuclear Information System (INIS)

Ganesh, Rangaraj; Torrijos, Michel; Sousbie, Philippe; Lugardon, Aurelien; Steyer, Jean Philippe; Delgenes, Jean Philippe

2015-01-01

The influence of different proportions of lignocellulosic substrate (cow manure with straw, CM) on the single-phase (conventional reactor) and two-phase (acidification/methanation with solids and liquid recirculation) digestion of a readily biodegradable substrate (fruit and vegetable waste, FVW) was investigated in order to determine the optimum cosubstrate ratio and the process best suited for codigestion. Both processes were fed initially with FVW, followed by FVW and CM at 80%:20% and 60%:40% (on volatile solids, VS basis) during an experiment run over eleven months. For the single-phase process, energy yield and VS destruction decreased by 11% and 9% with the 80%:20% FVW and CM ratio and by 16% and 17% with the 60%:40% feed ratio when compared to 100% FVW feed. For the two-phase process, energy yield and VS destruction decreased by 21% and 14% with 80%:20% feed ratio and by 48% and 33% with 60%:40% feed ratio compared to 100% FVW. Substrate solubilization in the acidification reactor was very efficient for all the feed proportions but it resulted in compounds other than volatile fatty acid (non-VFA COD) which were not easily amenable to methane generation. This led to a lower energy yield per kg of VS fed in the two-phase process compared to the single-phase process for the respective waste combination. For single-phase digestion, both 80%:20% and 60%:40% ratios were effective co-substrate combinations due to their higher energy yield. The two-phase process can be used for these ratios if higher VS reduction and a higher loading rate are the objectives. - Highlights: • Effect of cow manure addition on the digestion of fruit and vegetable waste studied. • Single and two-phase processes were compared for three different waste ratios. • Methane and energy yields were higher by single-phase than the two-phase process. • FVW-Cow manure ratios of 80%:20% and 60%:40% found effective for single-phase digestion. • Two-phase process resulted in higher solids

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.)

Potential evaluation of hydrogen peroxide for in-situ bioremediation of contaminated subsoils (chances, limitations, consequences). Final report; Untersuchung des Anwendungspotentials von Wasserstoffperoxid bei der biotechnologischen in-situ-Sanierung von kontaminierten Boeden (Moeglichkeiten, Grenzen, Folgen). Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Barenschee, E R; Weppen, P; Mueller, B G; Deckwer, W D; Muennich, K; Collins, H J

1992-06-01

Intention of this investigation was the development of methods for microbiological in situ decontamination of hydrocarbon polluted subsoils as an alternative or completion of pump and treat techniques. The changes and limitations of H{sub 2}O{sub 2} as an oxygensource was investigated on soil filled fixed bed bioreactors. The aerobic biodegradation of mineraloil products is limited by the supply of oxygen up to a conversion of 70-80%. During this state the degradation rate depends strongly on the oxygen intake rate. The degree of oxygen consumption is close to the theoretical value with regard to total mineralization and build up to biomass. At conversions higher than 70-80% the degradation rate decreases sharply due to transition from 0- to C- limitation. First attempts to increase the degradation rate by increasing the bioavailability at this state were successful. The behaviour of H{sub 2}O{sub 2} during transportation in the subsoil depends strongly on biological and physical/chemical parameters. Little remobilization of heavy metals were observed at the transition from reduced to oxidized state. (orig.) With 28 refs., 11 tabs., 34 figs. [Deutsch] Vorhabens Ziel ist die Methodenentwicklung zur mikrobiologisch unterstuetzten in-situ Dekontamination kohlenwasserstoffverunreinigter Boeden als Alternative oder Ergaenzung von hydraulischen Massnahmen. Die Moeglichkeiten und Grenzen von H{sub 2}O{sub 2} als Sauerstofftraeger werden anhand von Laborstudien mit Bodenbioreaktoren dargestellt. Der aerobe Abbau von Mineraloelprodukten ist bis zu Umsaetzen von 70-80% sauerstofflimitiert. Die Geschwindigkeit laesst sich durch die Sauerstoffeintragsrate beeinflussen. Der O{sub 2}-Nutzungsgrad liegt dabei nahe am theoretischen Wert unter Beruecksichtigung weitgehender Mineralisierung und Biomassenbildung. Bei hoeheren Umsaetzen verringert sich die Abbaugeschwindigkeit deutlich aufgrund des Uebergangs von 0- zum C-limitierten Zustand. Erste Ansaetze, die Bioverfuegbarkeit zu

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.)

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

1998-12-31

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)

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)

Production of carbon-13-labeled cadaverine by engineered Corynebacterium glutamicum using carbon-13-labeled methanol as co-substrate.

Science.gov (United States)

Leßmeier, Lennart; Pfeifenschneider, Johannes; Carnicer, Marc; Heux, Stephanie; Portais, Jean-Charles; Wendisch, Volker F

2015-12-01

Methanol, a one-carbon compound, can be utilized by a variety of bacteria and other organisms as carbon and energy source and is regarded as a promising substrate for biotechnological production. In this study, a strain of non-methylotrophic Corynebacterium glutamicum, which was able to produce the polyamide building block cadaverine as non-native product, was engineered for co-utilization of methanol. Expression of the gene encoding NAD+-dependent methanol dehydrogenase (Mdh) from the natural methylotroph Bacillus methanolicus increased methanol oxidation. Deletion of the endogenous aldehyde dehydrogenase genes ald and fadH prevented methanol oxidation to carbon dioxide and formaldehyde detoxification via the linear formaldehyde dissimilation pathway. Heterologous expression of genes for the key enzymes hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase of the ribulose monophosphate (RuMP) pathway in this strain restored growth in the presence of methanol or formaldehyde, which suggested efficient formaldehyde detoxification involving RuMP key enzymes. While growth with methanol as sole carbon source was not observed, the fate of 13C-methanol added as co-substrate to sugars was followed and the isotopologue distribution indicated incorporation into central metabolites and in vivo activity of the RuMP pathway. In addition, 13C-label from methanol was traced to the secreted product cadaverine. Thus, this synthetic biology approach led to a C. glutamicum strain that converted the non-natural carbon substrate methanol at least partially to the non-native product cadaverine.

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.

PANDA a multi-purpose thermal-hydraulics facility devoted to nuclear reactor containment safety analysis

International Nuclear Information System (INIS)

Paladino, Domenico

2014-01-01

This paper presents the multi purpose facility PANDA devised for the safety analysis of nuclear reactor containment. The passive safety systems for LWRs have been explained with details about the PAssive Nachzerfallswärmeabfuhr und Druck-Abbau Testanlage (PANDA)

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.)

Production of Xylitol from D-Xylose by Overexpression of Xylose Reductase in Osmotolerant Yeast Candida glycerinogenes WL2002-5.

Science.gov (United States)

Zhang, Cheng; Zong, Hong; Zhuge, Bin; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

2015-07-01

Efficient bioconversion of D-xylose into various biochemicals is critical for the developing lignocelluloses application. In this study, we compared D-xylose utilization in Candida glycerinogenes WL2002-5 transformants expressing xylose reductase (XYL1) in D-xylose metabolism. C. glycerinogenes WL2002-5 expressing XYL1 from Schefferomyces stipitis can produce xylitol. Xylitol production by the recombinant strains was evaluated using a xylitol fermentation medium with glucose as a co-substrate. As glucose was found to be an insufficient co-substrate, various carbon sources were screened for efficient cofactor regeneration, and glycerol was found to be the best co-substrate. The effects of glycerol on the xylitol production rate by a xylose reductase gene (XYL1)-overexpressed mutant of C. glycerinogenes WL2002-5 were investigated. The XYL1-overexpressed mutant produced xylitol from D-xylose using glycerol as a co-substrate for cell growth and NAD (P) H regeneration: 100 g/L D-xylose was completely converted into xylitol when at least 20 g/L glycerol was used as a co-substrate. XYL1 overexpressed mutant grown on glycerol as co-substrate accumulated 2.1-fold increased xylitol concentration over those cells grown on glucose as co-substrate. XYL1 overexpressed mutant produced xylitol with a volumetric productivity of 0.83 g/L/h, and a xylitol yield of 98 % xylose. Recombinant yeast strains obtained in this study are promising candidates for xylitol production. This is the first report of XYL1 gene overexpression of C. glycerinogenes WL2002-5 for enhancing the efficiency of xylitol production.

Anaerobic co-digestion of agricultural by-products with manure, for enhanced biogas production

DEFF Research Database (Denmark)

Søndergaard, Marie M.; Fotidis, Ioannis; Kovalovszki, Adam

2015-01-01

Biogas is extensively promoted as a promising renewable energy. Therefore, the search of appropriate co-substrates has come into focus. In this study, we examined the potential of using agricultural byproducts as alternative co-substrates for increased biogas production. The biochemical methane p...

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

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)

Environmentally compatible sewage sludge disposal; Umweltgerechte Klaerschlammentsorgung

Energy Technology Data Exchange (ETDEWEB)

Mueller, J. [Technische Univ. Braunschweig (Germany). Inst. fuer Mechanische Verfahrenstechnik; Schwedes, J. [Technische Univ. Braunschweig (Germany). Inst. fuer Mechanische Verfahrenstechnik

1997-09-01

Cleaning of municipal and industrial waste water is done by means of biological processes: micro-organisms degrade pollutants. The resulting products are, besides cleaned waste water, sewage sludge and surplus sludge. Their disposal involves ecological and economic problems. One approach to their partial disposal is their degradation in a digester. Approximately one half of the organic substance is converted by anaerobic bacteria into energy-rich biogas. Optimization of this digestion process accelerates the anaerobic degradation process, increases the accruing amount of digester gas and reduces the volume of digested sludge to be disposed of. With these objectives, the Institute fuer Mechanische Verfahrenstechnik is conducting research into the mechanical treatment of micro-organisms remaining in surplus sludge by means of different treatment devices. The project is sponsored under the programme of the Deutsche Forschungsgemeinschaft DFG ``Biological processes with dispersive solids``. Mechanical treatment renders the cell constituents exploitable to anaerobic bacteria; the resulting sludge degradation is more rapid and more complete. (orig./ABI) [Deutsch] Zur Reinigung haeuslicher und industrieller Abwaesser werden biologische Prozesse eingesetzt. Dabei sorgen Mikroorganismen fuer den Abbau der Verunreinigungen. Neben dem gereinigten Abwasser fallen Primaer- und Ueberschussschlamm an, deren Entsorgung oekologische und oekonomische Probleme verursacht. Ein Weg zur partiellen Beseitigung dieser Klaerschlaemme ist ihr Abbau in einem Faulbehaelter. Dabei wird etwa die Haelfe der organischen Substanz durch anaerobe Bakterien zu einem energiereichen Biogas umgewandelt. Eine Optimierung dieses Faulprozesses beinhaltet: 1. Beschleunigung des anaeroben Abbauprozesses, 2. Erhoehung der anfallenden Faulgasmenge und 3. Reduzierung der zu entsorgenden Faulschlammenge. Mit diesen Zielsetzungen wird am Institut fuer Mechanische Verfahrenstechnik im Rahmen der DFG

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.)

GTP plus water mimics ATP in the active site of protein kianse 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...

Sulphur fate and anaerobic biodegradation potential during co-digestion of seaweed biomass (Ulva sp.) with pig slurry.

Science.gov (United States)

Peu, P; Sassi, J-F; Girault, R; Picard, S; Saint-Cast, Patricia; Béline, F; Dabert, P

2011-12-01

Seaweed (Ulva sp.) stranded on beaches were utilized as co-substrate for anaerobic digestion of pig slurry in three-month co-digestion tests in pilot scale anaerobic digesters in the laboratory. The methanogenic potential of Ulva sp. was low compared to that of other potential co-substrates available for use by farmers: 148 N m3CH4/t of volatile solids or 19 N m3CH4/t of crude product. When used as a co-substrate with pig manure (48%/52% w/w), Ulva sp. seaweed did not notably disrupt the process of digestion; however, after pilot stabilisation, biogas produced contained 3.5% H2S, making it unsuitable for energy recovery without treatment. Sequentially addition of the sulphate reduction inhibitor, potassium molybdate, to a final concentration of 3mM, temporarily reduced H2S emissions, but was unable to sustain this reduction over the three-month period. According to these pilot tests, the use of seaweed stranded on beaches as co-substrate in farm-based biogas plants shows some limitations. Copyright © 2011 Elsevier Ltd. All rights reserved.

In Situ Bioremediation of Energetic Compounds in Groundwater

Science.gov (United States)

2012-05-01

negligible. Thus, this project clearly shows that in situ bioremediation of explosives in groundwater using active-passive cosubstrate addition can...Arlington, NJ, offices), the National Research Council (NRC) Biotechnology Research Institute (Montreal, Canada) and the Environmental Technology...NDAB are unlikely to accumulate during in situ anaerobic bioremediation explosives using cheese whey as a cosubstrate. 7.4 ADEQUATE DISTRIBUTION OF

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lebenspartnerschaften mit und ohne Kinder: Ambivalenzen der Institutionalisierung privater Lebensformen

OpenAIRE

Lüscher, Kurt; Grabmann, Barbara

2002-01-01

Die historisch neue Aufgabe der rechtlichen Regelung von Lebensgemeinschaften gleichgeschlechtlich orientierter Menschen beinhaltet den Abbau von Diskriminierungen und stellt Fragen nach dem Verständnis von Ehe und Familie sowie deren Verhältnis zu anderen privaten Lebensformen. Die Analyse der zahlenmäßigen Verbreitung gleichgeschlechtlicher Partnerschaften und der Begründung ihrer Verrechtlichung verweist auf spezifische Ambivalenzen der Institutionalisierung privater Lebensformen. Ein Über...

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

Recht und soziales Kapital im Wohlfahrtsstaat

OpenAIRE

Karstedt, Susanne

1997-01-01

'Das Konzept des sozialen Kapitals spielt eine zentrale Rolle in der Diskussion um den Um- und Abbau des Wohlfahrtsstaates. Zerstört der Wohlfahrtsstaat soziales Kapital? Können staatliche Sozialleistungen durch das soziale Kapital in Familien, Nachbarschaften und Gemeinden umstandslos ersetzt werden, und individuelle Rechtsansprüche als Forderungen an diese sozialen Netzwerke zurückverwiesen werden? Kann die angestrebte 'Verantwortungsgesellschaft' (Etzioni) die Leistungen übernehmen, mit de...

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...

Pilot tests in enhanced ultrasonic disintegration of sewage sludge; Pilotversuche zur Intensivierung der Schlammfaulung durch Klaerschlammdesintegration mit Ultraschall

Energy Technology Data Exchange (ETDEWEB)

Nickel, K.; Tiehm, A.; Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

1999-07-01

The work has the objective to optimize ultrasonic disintegration of sewage sludge in permant routine operation. Anaerobic degradation of disintegrated crude and excess sludge was investigated on a pilot scale at a municipal sewage treatment plant. (orig.) [German] Ziel dieser Arbeit ist die Optimierung der Klaerschlammdesintegration mit Ultraschall im praktischen Dauerbetrieb. Der anaerobe Abbau von desintegriertem Roh- und Ueberschussschlamm wurde im Pilotmassstab vor Ort auf einer kommunalen Klaeranlage untersucht. (orig.)

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.)

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)

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

1997-12-31

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)

Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde

OpenAIRE

Plagens, Heike

2001-01-01

In dieser Arbeit wurden die bimolekularen Geschwindigkeitskonstanten für die Reaktionen von Hexanal, Heptanal, Oktanal und Nonanal mit OH and Cl Radikalen bei (298 ± 2) K und (1000 ± 20) mbar experimentell bestimmt. Ebenso wurde die Chlorgeschwindigkeitskonstante für Butanal gemessen. Die Werte sind (in Einheiten von cm3 Molekül-1 s-1) in Tabelle 1 zusammengefaßt. Tabelle 1: Aldehyde kOH kCl Butanal - (2,21 ± 0,16) · 10-10 Hexan...

Zur Wirkung hoher Temperaturen auf vorratsschädliche Insekten

OpenAIRE

Adler, Cornel

2008-01-01

Vorratsschädliche Insekten sind Spezialisten, die in der Lage sind, trockene pflanzliche Materialien aufzuspüren, zu besiedeln und damit über die Befeuchtung durch Respiration dem Abbau durch weitere Organismen (Pilze, Milben, Bakterien) zuzuführen. Auf diese Weise sind sie die Auslöser eines Kompostierungsprozesses. Durch ihr hervorragendes Orientierungsvermögen entlang eines Duftstoffgradienten finden sie sich regelmäßig in Vorratslagern und Gebäuden der Lebens- und Futtermittelverarbeitung...

Metatheseabbau von Butadien-Acrylnitril-Copolymeren und Neue Pfropfcopolymere aus Norbornen-terminierten Poly(ferrocenyldimethylsilan)en

OpenAIRE

Müller, Julia Maria

2008-01-01

Der Fokus des ersten Teils der Arbeit lag auf der Untersuchung des Einflusses des Katalysators, des Olefins und von Additiven auf den Metatheseabbau von Nitrilkautschuk. Die Ergebnisse zeigten, dass der aktivitätssenkende Einfluss der Nitrilgruppen den Kreis wirksamer Katalysatoren einschränkt. Der Abbau des NBR mit linearen α-Olefine führte zu einer stärkeren Molmassenabsenkung, als die Verwendung di- oder trisubstituierter Olefine. Enorme Aktivitätszunahmen wurden mit Hilfe der Additive erh...

Der Zellzyklusregulator Rca1 - Inhibitor und Substrat des Anaphase-Promoting-Komplexes in Drosophila melanogaster

OpenAIRE

Morgenthaler, Christoph

2014-01-01

Ein wichtiger Kontrollmechanismus des Zellzyklus ist die irreversible Proteolyse von Zellzyklus-Regulatoren. Dabei markieren E3-Ligasen Zielproteine durch Ubiquitinmoleküle. Für den Abbau in der Mitose und der G1-Phase reguliert der APC/C-Komplex (Anaphase-Promoting-Complex/Cyclosome) als E3-Ligase den zeitlichen Verlauf des Zellzyklus. Die Aktivität des APC/C wiederum wird in den übrigen Zellzyklusstadien durch Phosphorylierung und durch Proteine der Rca1/Emi1-Proteinfamilie inaktiv gehalten...

Anwendung stabiler Isotope zur Beschreibung des mikrobiellen Abbaus organischer Schadstoffe in kontaminierten Aquiferen

OpenAIRE

Vieth, Andrea

2003-01-01

Der mikrobielle in-situ Abbau organischer Schadstoffe ist mit einer Änderung der Isotopenverhältnisse (12C/13C; H/D) verbunden. Das Ausmaß der Isotopenfraktionierung ist abhängig von der initialen biochemischen Reaktion und variiert mit der Größe des Substratmoleküls bzw. der Anzahl der Kohlenstoff- bzw. Wasserstoffatome. Für die Anwendung dieses Isotopenkonzepts zur Beschreibung des mikrobiellen Abbaus von Schadstoffen im Grundwasser muss ausgeschlossen werden können, dass andere Prozesse ei...

Proteasen in pflanzlichen Organellen

OpenAIRE

Helm, Michael

2006-01-01

Der Programmierte Zelltod (PCD) ist essentiell für die Entwicklung der Pflanze, im Speziellen für den Abbau nicht mehr benötigter Gewebe zur Rückführung von Nährstoffen an die weiterlebenden Teile der Pflanze. Ricinus (R. communis) speichert Öl und Eiweiß in einem lebenden Endosperm, das die Kotyledonen umgibt. Die Speicherstoffe werden während der Keimung mobilisiert und den Kotyledonen zugeführt. Der PCD des Endosperm-Gewebes wird eingeleitet, sobald dieser Transfer abgeschlossen ist. Ein s...

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

2017-02-01

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Entwicklung einer Methode zur monetären Bewertung des Wassers für ein Unternehmen unter Einbeziehung des Wasser-Fußabdrucks

OpenAIRE

Hentschel, Nora

2011-01-01

Wassernutzung und Abbau der Frischwasser-Ressourcen sind heutzutage ein Thema, das als so wichtig wahrgenommen wird wie der Klimawandel. Wasser wird somit zunehmend Auswirkungen auf den ökonomischen Wert von Unternehmen haben. Ziel der vorliegenden Arbeit ist es, den monetären Wert des Wassers mithilfe des Wasser-Fußabdrucks zu bestimmen. Hierfür werden nach einer kurzen Einführung in Kapitel 2 der ökologische Fußabdruck, der CO2-Fußabdruck und der Wasser-Fußabdruck kurz vorgestellt und in...

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

International Nuclear Information System (INIS)

Skovsgaard, Lise; Jacobsen, Henrik Klinge

2017-01-01

Biogas production is characterised by economies of scale in capital and operational costs of the plant and diseconomies of scale from transport of input materials. We analyse biogas in a Danish setting where most biogas is based on manure, we use a case study with actual distances, and find that the benefits of scale in capital and operational costs dominate the diseconomies of increasing transport distances to collect manure. To boost the yield it is common to use co-substrates in the biogas production. We investigate how costs and income changes, when sugar beet is added in this case study, 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 crops in Danish legislation. - Highlights: • For Denmark we find economies of scale in biogas production based on pure manure. • Adding sugar beet outweigh economy of scale due to increased transport costs. • We investigate the main risks associated with input prices, yield and output prices. • Biogas fed into the gas grid should receive similar support as directly used in CHP. • Regulation should allow large biogas plants with few restrictions on co-substrates.

Anaerobic degradation of anionic surfactants by indigenous microorganisms from sediments of a tropical polluted river in Brazil

Directory of Open Access Journals (Sweden)

Iolanda Cristina Silveira Duarte

2015-03-01

Full Text Available Linear alkylbenzene sulfonate (LAS is widely used in the formulation of domestic and industrial cleaning products, the most synthetic surfactants used worldwide. These products can reach water bodies through the discharge of untreated sewage or non-effective treatments. This study evaluates the ability of the microorganisms found in the Tietê river sediment to degrade this synthetic surfactant. The experiment was conducted in a bioreactor, operated in batch sequences under denitrifying conditions, with cycles of 24 hours and stirring at 150rpm, using 430mL of sediments and 1 070mL of a synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose. LAS was added at different concentrations of 15mg/L and 30mg/L. The reactor operation was divided into the biomass adaptation to the synthetic substrate without LAS and three experimental conditions: a addition of 15mg/L of LAS; b 50% reduction the co-substrate concentration and 15mg/L of LAS, and c addition of 30mg/L of LAS and 100% co-substrate concentration. The results showed that the degradation efficiency of LAS was directly related to the addition of co-substrates and the population of denitrifying bacteria. The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic loads. The reduction in the co-substrates concentration was directly influenced by the number of denitrifying bacteria (2.2x10(13 to 1.0x10(8MPN/gTVS, and consequently, LAS degradation (60.1 to 55.4%. The sediment microorganisms in the Tietê river can be used as an alternative inoculum in the treatment of wastewater with nitrate and LAS contamination.

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.

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)

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.

Transglutaminase inhibition: possible therapeutic mechanisms to protect cells from death in neurological disorders

Directory of Open Access Journals (Sweden)

Nicola Gaetano Gatta

2017-10-01

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, and 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. Here we describe 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.

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

International Nuclear Information System (INIS)

Alvarez, Rene; Liden, 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 deg. 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

Vegetable processing wastes addition to improve swine manure anaerobic digestion: Evaluation in terms of methane yield and SEM characterization

International Nuclear Information System (INIS)

Molinuevo-Salces, Beatriz; González-Fernández, Cristina; Gómez, Xiomar; García-González, María Cruz; Morán, Antonio

2012-01-01

Highlights: ► Vegetable waste as co-substrate for swine manure anaerobic digestion. ► Two hydraulic retention times of 25 and 15 d, respectively. ► SEM characterization of anaerobic sludges to observe microbial composition. ► Vegetable waste as co-substrate increases methane yields up to three times. ► Microbial composition changes after 120 d of digestion. -- Abstract: The effect of adding vegetable waste as a co-substrate in the anaerobic digestion of swine manure was investigated. The study was carried out at laboratory scale using semi-continuous stirred tank reactors working at 37 °C. Organic loading rates (OLRs) of 0.4 and 0.6 g VS L −1 d −1 were evaluated, corresponding to hydraulic retention times (HRTs) of 25 and 15 d, respectively. The addition of vegetable wastes (50% dw/dw) resulted in an improvement of 3 and 1.4-fold in methane yields at HRTs of 25 and 15 d, respectively. Changes on microbial morphotypes were studied by Scanning Electron Microscopy (SEM). Samples analyzed were sludge used as inoculum and digestate obtained from swine manure anaerobic reactors. SEM pictures demonstrated that lignocellulosic material was not completely degraded. Additionally, microbial composition was found to change to cocci and rods morphotypes after 120 d of anaerobic digestion.

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...

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

Foaming is one of the most common and important problems in biogas plants, leading to severe operational, economical, and environmental drawbacks. Because addition of easily degradable co-substrates for boosting the biogas production can suddenly raise the foaming problem, the full-scale biogas...... 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....

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.)

Hyperglycemia and Oxidative Stress Strengthen the Association Between Myeloperoxidase and Blood Pressure

NARCIS (Netherlands)

van der Zwan, L.P.; Scheffer, P.G.; Dekker, J.M.; Stehouwer, C.D.A.; Heine, R.J.; Teerlink, T.

2010-01-01

Scavenging of the vasodilator nitric oxide by myeloperoxidase activity in the vasculature may contribute to hypertension. Because hydrogen peroxide is a cosubstrate of myeloperoxidase, hyperglycemia-induced oxidative stress may strengthen the relationship between myeloperoxidase and blood pressure.

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...... biogas reactor was possible with biomass share of 10%, leading to energy production of 280 GJ/day. The digestion of pretreated meadow grass as alternative co-substrate had clearly positive impact in all the examined scenarios, leading to increased biogas production in the range of 10%-20%.......This study investigated the efficiency of commercially available harvesting machines for mechanical pretreatment of meadow grass, in order to enhance the energy yield per hectare. Excoriator was shown to be the most efficient mechanical pretreatment increasing the biogas yield of grass by 16...

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

NARCIS (Netherlands)

Oldenhuis, R.; Vink, Ruud L.J.M.; Janssen, D. B.; Witholt, B.

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

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,

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

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

Biogas production is characterised by economies of scale in capital and operational costs of the plant and diseconomies of scale from transport of input materials. We analyse biogas in a Danish setting where most biogas is based on manure, we use a case study with actual distances, and find...... that the benefits of scale in capital and operational costs dominate the diseconomies of increasing transport distances to collect manure. To boost the yield it is common to use co-substrates in the biogas production. We investigate how costs and income changes, when sugar beet is added in this case study......, 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...

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.

The NAD(+) precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesity

NARCIS (Netherlands)

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

2012-01-01

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(+)

Harmonisation of fire testing of conveyor belts for underground applications within the EC; Harmonisierung der brandtechnischen Pruefverfahren von Foerdergurten fuer den Einsatz unter Tage innerhalb der EG

Energy Technology Data Exchange (ETDEWEB)

Foit, W. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Dortmund (Germany). Fachstelle fuer Brand- und Explosionsschutz unter Tage - Versuchsgrube Tremonia

1998-12-01

The mining countries of the EC still have different regulations for fire testing of conveyor belts. The test methods will be harmonized for the Common Market, and requirements on conveyor belts will be standardized within the EC. A new EC standard will be drawn up. [Deutsch] Zur Zeit sind in den bergbaubetreibenden Laendern der EG noch unterschiedliche Verfahren zur brandtechnischen Pruefung von Foerdergurten vorgeschrieben. Mit dem Inkrafttreten des Gemeinsamen Marktes und der damit zusammenhaengenden Forderung nach Abbau von Handelshemmnissen sollen diese Pruefverfahren harmonisiert werden. Ziel ist es, die an die Foerdergurte zu stellenden brandtechnischen Anforderungen innerhalb der EG zu vereinheitlichen. Es soll deshalb eine europaeische Norm zur Beurteilung des Brandverhaltens und der Brandausbreitung an Foerdergurten fuer den Kohlenbergbau unter Tage erstellt werden. (orig./MSK)

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

African Journal of Applied Zoology and Environmental Biology - Vol ...

African Journals Online (AJOL)

Effect of cosubstrates on primary biodegradation of triphenylmethane dyes by Pseudomonas sp. EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD ... Utilisation of azo and triphenylmethane dyes as sole source of carbon, energy and nitrogen by Bacillus sp. EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

USE OF BENZOATE TO ESTABLISH REACTIVE BUFFER ZONES FOR ENHANCED ATTENUATION OF BTX MIGRATION: AQUIFER COLUMN EXPERIMENTS (R823420)

Science.gov (United States)

Flow-through aquifer columns were used to evaluate the efficacy of using benzoate as a biostimulatory substrate to enhance the aerobic biodegradation of benzene, toluene, and o-xylene (BTX), fed continuously at low concentra tions (about 0.2 mg/L each). When used as a cosubstr...

Feasibility study of a methanization unit. Drafting of specifications for any grantee of an ADEME's financial competition within the frame of a decision support arrangement

International Nuclear Information System (INIS)

2012-01-01

This study aims at providing a project developer with technical, economic and regulatory elements so that he can determine the feasibility of a methanization project on his farm. After an indication of criteria to be met, it describes how energy needs are to be studied: description of the present situation, determination of energy needs related to housing buildings and to farm buildings, needs external to the farm. It describes how the methanizable substrate resource is to be analysed with a distinction between resources produced by farming (cattle and agricultural effluents, co-substrates), by agricultural products not produced by the farm, and non agricultural co-substrates. It describes how the project size is to be determined with respect to methanization (biogas production, biogas production systems, biogas valorisation), to valorisation of digestate or of its by-products, to regulations and technical requirements, to environmental impacts (greenhouse gas emissions, substitution of fossil energies). It describes the economic analysis (determination of investments, of incomes and operation costs)

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.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhancing biohydrogen production through sewage supplementation of composite vegetable based market waste

International Nuclear Information System (INIS)

Mohanakrishna, G.; Kannaiah Goud, R.; Venkata Mohan, S.; Sarma, P.N.

2010-01-01

The function of domestic sewage supplementation as co-substrate with composite vegetable based market waste was studied during the process of fermentative hydrogen (H 2 ) production. Significant improvement in H 2 production and substrate degradation were noticed upon supplementing the waste with domestic sewage. Maximum H 2 production (cummulative) was observed at 5.2 kg COD/m 3 with pulp operation and 4.8 kg COD/m 3 with non-pulp operation accounting for improvement of 51 and 55% respectively after sewage upplementation. Substrate degradation was also found to improve with respect to both carbohydrates [8% (with pulp); 5% (non-pulp)] and chemical oxygen demand [COD, 12% (with pulp); 13% (non-pulp)] after adding domestic sewage. Specific H 2 yield improved especially at lower concentrations. Supplementation of waste with co-substrate helps to maintain good buffering microenvironment supports fermentation process and in addition provides micro-nutrients, organic matter and microbial biomass. Variation in the outlet pH was less in supplementation experiments compared to normal operation. (author)

Application of a novel enzymatic pretreatment using crude hydrolytic extracellular enzyme solution to microalgal biomass for dark fermentative hydrogen production.

Science.gov (United States)

Yun, Yeo-Myeong; Kim, Dong-Hoon; Oh, You-Kwan; Shin, Hang-Sik; Jung, Kyung-Won

2014-05-01

In this study, a novel enzymatic pretreatment of Chlorella vulgaris for dark fermentative hydrogen production (DFHP) was performed using crude hydrolytic extracellular enzyme solution (CHEES) extracted from the H2 fermented effluent of food waste. It was found that the enzyme extracted at 52 h had the highest hydrolysis efficiency of microalgal biomass, resulting in the highest H2 yield of 43.1 mL H2/g dry cell weight along with shorter lag periods. Even though a high amount of VFAs was accumulated in CHEES, especially butyrate, the fermentative bacteria on the DFHP was not affected from product inhibition. It also appears that the presence of organic acids, especially lactate and acetate, contained in the CHEES facilitated enhancement of H2 production acted as a co-substrate. Therefore, all of the experimental results suggest that the enhancement of DFHP performance caused by CHEES has a dual role as the hydrolysis enhancer and the co-substrate supplier. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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.

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

Microbial remediation of soil pollution from ore mining. Part 3: Cyanide removal and biosorption of heavy metals in mining and processing water; Untersuchungen zur mikrobiellen Sicherung von Erzbergbaualtlasten. Teilvorhaben 3: Cyanidabbau und Biosorption von Schwermetallen in Abwaessern aus Erzbergbau- und Aufbereitungsbetrieben. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Blumenroth, P.; Bosecker, K.

1999-12-01

1. Cyanide degradation: Of the cyanide- and thiocyanate-degrading bacteria, Burkholderia cepacia and Pseudomonas spec. were the most effective. 2. Biosorption: Of the isolates suited for biosorption of heavy metals, 597-A (non-identifiable) and 597-A2 (Aspergillus fumigatis) had the biggest potential. The sorption capacity of the fungi for metals varied with the C source used for their growth: apple juice > molasses > glucose. The fungi are not cyanide-sensitive and can even degrade cyanide. Living biomass had better metal sorption efficiencies than dead mycelium. The biosorption rates in waste water were usually higher than in broth. Depending on the metal composition and concentrations and on the exposure time and volume of the mycelia, up to 85 % of the initial concentration was removed from the liquid phase. The capacity of different biomasses for the sorption of metal mixtures was between 65 and 80 mg/g of dry matter depending on the experimental conditions, with peak rates up to 100 mg/g. [German] 1. Cyanidabbau: Von den zum Abbau von Cyaniden und Thiocyanat befaehigten Bakterien erwiesen sich Burkholderia cepacia und Pseudomonas spec. als am besten geeignet. 2. Biosorption: Von den zur Biosorption von Schwermetallen befaehigten Isolaten wiesen 597-A1 (nicht identifizierbar) und 597-A2 (Aspergillus fumigatus) das groesste Potential auf. Die Sorptionsleistung der Pilze fuer Metalle war abhaengig von der C-Quelle, die zur Anzucht verwendet wurde: Apfelsaft>Melasse>Glucose. Die Pilze sind unempfindlich gegenueber Cyanid und sogar zu dessen Abbau in der Lage. Lebende Biomasse sorbierte mehr Metalle als abgetoetetes Pilzmyzel. Die in Abwaessern ermittelten Biosorptionsraten waren meist hoeher als die in Medium erzielten Raten. Je nach Zusammensetzung und Konzentration der Metalle sowie Einwirkdauer und Menge des eingesetzten Pilzmyzels wurden bis zu 85% des Ausgangsgehaltes aus der Fluessigphase entfernt. Die Kapazitaet verschiedener Biomassen fuer die Sorption

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

Author Details

African Journals Online (AJOL)

Ogugbue, C J. Vol 7 (2005) - Articles Effect of cosubstrates on primary biodegradation of triphenylmethane dyes by Pseudomonas sp. Abstract PDF · Vol 7 (2005) - Articles Inhibitory effect of azo dyes on ammoni-n oxidation by nitrtosomonas. Abstract PDF · Vol 6 (2004) - Articles Effect of ph and nutrient starvation on ...

Less mining-induced damage through slowed-down working. Geringe Bergbauschaeden durch langsamen Abbau

Energy Technology Data Exchange (ETDEWEB)

Kratzsch, H [Technische Univ. Berlin (Germany). Inst. fuer Bergbauwissenschaften

1994-10-01

Today's widely spread view that rapid deformation will enhance damage to buildings was not underpinned by major reasons of soil mechanics and building physics. It is true that a shower rise in deformation will favour grain relocation in the foundation soil and, as a result, will diminish the soil pressure on cellar walls or on pipes embedded in the ground in the pressurized zone and will reduce the floor-level pressure peak in the bending zone by subsequent settling of foundation components. However, damage will not be found to differ in degree if deformation had lasted for 50 days ([nu][sub A]=8 m/d) or 200 days ([nu][sub A]=2 m/d). It may be assumed to be hardly relevant for the degree of damage sustained if bending, shifting (friction), tearing (shearing) or pressing of a building part (e.g. wall, ceiling, pillar), or of a building element (e.g. brick, mortar injoints) or of a building composed of all these parts rise to their final levels within a period of 50 or 200 days. (orig./MSK)

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)

Energetic conversion (biogas) of used edible oils by means of co-digestion together with various waste materials from the food industry

International Nuclear Information System (INIS)

Membrez, Y.; Fruteau de Laclos, H.

2002-01-01

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 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)

Sequencing biological acidification of waste-activated sludge aiming to optimize phosphorus dissolution and recovery.

Science.gov (United States)

Guilayn, Felipe; Braak, Etienne; Piveteau, Simon; Daumer, Marie-Line

2017-06-01

Phosphorus (P) recovery in wastewater treatment plants (WWTP) as pure crystals such as struvite (MgNH 4 PO 4 .6H 2 O), potassium struvite (KMgPO 4 .6H 2 O) and calcium phosphates (e.g. Ca 3 (PO 4 ) 2 ) is an already feasible technique that permits the production of green and marketable fertilizers and the reduction of operational costs. Commercial crystallizers can recovery more than 90% of soluble P. However, most of the P in WWTP sludge is unavailable for the processes (not dissolved). P solubilization and separation are thus the limiting steps in P-crystallization. With an innovative two-step sequencing acidification strategy, the current study has aimed to improve biological P solubilization on waste-activated sludge (WAS) from a full-scale plant. In the first step (P-release), low charges of organic waste were used as co-substrates of WAS pre-fermentation, seeking to produce volatile fatty acids to feed the P-release by Polyphosphate-accumulating organisms, while keeping its optimal metabolic pH (6-7). In this phase, milk serum, WWTP grease, urban organic waste and collective restaurant waste were individually applied as co-substrates. In the second step (P-dissolution), pH 4 was aimed at as it allows the dissolution of the most common precipitated species of P. Biological acidification was performed by white sugar addition, as a carbohydrate-rich organic waste model, which was compared to chemical acidification by HCl (12M) addition. With short retention times (48-96 h) and without inoculum application, all experiences succeeded on P solubilization (37-55% of soluble P), principally when carbohydrate-rich co-substrates were applied. Concentrations from 270 to 450 mg [Formula: see text] were achieved. [Formula: see text].

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)

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.

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

International Nuclear Information System (INIS)

Yang, Lihui; Zhang, Yongming; Bai, Qi; Yan, Ning; Xu, Hua; Rittmann, Bruce E.

2015-01-01

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

The structure of apo and holo forms of xylose reductase, a dimeric aldo-keto reductase from Candida tenuis.

Science.gov (United States)

Kavanagh, Kathryn L; Klimacek, Mario; Nidetzky, Bernd; Wilson, David K

2002-07-16

Xylose reductase is a homodimeric oxidoreductase dependent on NADPH or NADH and belongs to the largely monomeric aldo-keto reductase superfamily of proteins. It catalyzes the first step in the assimilation of xylose, an aldose found to be a major constituent monosaccharide of renewable plant hemicellulosic material, into yeast metabolic pathways. It does this by reducing open chain xylose to xylitol, which is reoxidized to xylulose by xylitol dehydrogenase and metabolically integrated via the pentose phosphate pathway. No structure has yet been determined for a xylose reductase, a dimeric aldo-keto reductase or a family 2 aldo-keto reductase. The structures of the Candida tenuis xylose reductase apo- and holoenzyme, which crystallize in spacegroup C2 with different unit cells, have been determined to 2.2 A resolution and an R-factor of 17.9 and 20.8%, respectively. Residues responsible for mediating the novel dimeric interface include Asp-178, Arg-181, Lys-202, Phe-206, Trp-313, and Pro-319. Alignments with other superfamily members indicate that these interactions are conserved in other dimeric xylose reductases but not throughout the remainder of the oligomeric aldo-keto reductases, predicting alternate modes of oligomerization for other families. An arrangement of side chains in a catalytic triad shows that Tyr-52 has a conserved function as a general acid. The loop that folds over the NAD(P)H cosubstrate is disordered in the apo form but becomes ordered upon cosubstrate binding. A slow conformational isomerization of this loop probably accounts for the observed rate-limiting step involving release of cosubstrate. Xylose binding (K(m) = 87 mM) is mediated by interactions with a binding pocket that is more polar than a typical aldo-keto reductase. Modeling of xylose into the active site of the holoenzyme using ordered waters as a guide for sugar hydroxyls suggests a convincing mode of substrate binding.

Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

DEFF Research Database (Denmark)

Panichnumsin, Pan; Nopharatana, Annop; Ahring, Birgitte Kiær

2010-01-01

digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m...

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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)

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

1997-12-31

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)

Degradation of PAH by white-rot fungi. Abbau von polyzyklischen aromatischen Kohlenwasserstoffen durch Weissfaeulepilze

Energy Technology Data Exchange (ETDEWEB)

Majcherczyk, A [Goettingen Univ. (Germany). Arbeitsgruppe Technische Mykologie; Zeddel, A [Goettingen Univ. (Germany). Arbeitsgruppe Technische Mykologie; Kelschebach, M [Goettingen Univ. (Germany). Arbeitsgruppe Technische Mykologie; Loske, D [Goettingen Univ. (Germany). Arbeitsgruppe Technische Mykologie; Huettermann, A [Goettingen Univ. (Germany). Arbeitsgruppe Technische Mykologie

1993-04-01

The reports on exciting good results on degradation of xenobiotic substances by Phanaerochaete chrysosporium obtained in the early eighties in liquid cultures were confirmed for a wide spectrum of white-rot fungi under soil conditions. The substance classes which were successfully degraded were: PAH, PCB and TNT. The results obtained in the laboratory could in the case of PAH be transfered to a larger scale. The addition of known inducers of lignolytic enzymes did not increase the rate of degradation of xenobiotics of the white-rot fungi. The most critical parameter is the oxygen supply. For improving the economics of the process, cheap methods of growing the fungi were developed, such as the treatment of the substrate with detergents or the supplementing with potato pulp. These treatments have the advantage that they do not require expensive thermal activation of the substrate. Both processes provide excellent growth of the fungi without additional treatments. The at present best process for bioremediation of soils with white-rot fungi includes the following steps: liquification of the soil to a slurry, addition of the fungi together with possibly other substances e.g. tensides, solidification of the slurry by the addition of a lignocellulosic substrate which converts the slurry to a crumbly solid which can be well areated. The mass is then transferred to a closed container and incubated under controlled aeration. The problems being unsolved are: upscaling to the cubic meter scale, the lack of bioavailability of the xenobiotics in many soils, the lack of information about the degradation products and the most suitable way of determining the residual toxicity of the treated soils. (orig.)

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.

Evaluation of the energetic potential of sewage sludge by characterization of its organic composition.

Science.gov (United States)

Schaum, C; Lensch, D; Cornel, P

2016-01-01

The composition of sewage sludge and, thus, its energetic potential is influenced by wastewater and wastewater treatment processes. Higher or lower heating values (HHV or LHV) are decisive factors for the incineration/gasification/pyrolysis of sewage sludge. The HHV is analyzed with a bomb calorimeter and converted to the LHV. It is also possible to calculate the heating value via chemical oxygen demand (COD), total volatile solids (TVS), and elemental composition. Calculating the LHV via the COD provides a suitable method. In contrast, the correlation of the HHV or LHV with the TVS is limited. One prerequisite here is a constant specific energy density; this was given with the types of sewage sludge (primary, surplus/excess, and digested sludge) investigated. If the energy density is not comparable with sewage sludge, for instance with the co-substrate (bio-waste, grease, etc.), the estimation of the heating value using TVS will fail. When calculating the HHV or LHV via the elemental composition, one has to consider the validity of the coefficients of the calculation equation. Depending on the organic composition, it might be necessary to adjust the coefficients, e.g. when adding co-substrates.

Enzyme characteristics of aminotransferase FumI of Sphingopyxis sp. MTA144 for deamination of hydrolyzed fumonisin B₁.

Science.gov (United States)

Hartinger, Doris; Schwartz, Heidi; Hametner, Christian; Schatzmayr, Gerd; Haltrich, Dietmar; Moll, Wulf-Dieter

2011-08-01

Fumonisins are carcinogenic mycotoxins that are frequently found as natural contaminants in maize from warm climate regions around the world. The aminotransferase FumI is encoded as part of a gene cluster of Sphingopyxis sp. MTA144, which enables this bacterial strain to degrade fumonisin B(1) and related fumonisins. FumI catalyzes the deamination of the first intermediate of the catabolic pathway, hydrolyzed fumonisin B(1). We used a preparation of purified, His-tagged FumI, produced recombinantly in Escherichia coli in soluble form, for enzyme characterization. The structure of the reaction product was studied by NMR and identified as 2-keto hydrolyzed fumonisin B(1). Pyruvate was found to be the preferred co-substrate and amino group receptor (K (M) = 490 μM at 10 μM hydrolyzed fumonisin B(1)) of FumI, but other α-keto acids were also accepted as co-substrates. Addition of the co-enzyme pyridoxal phosphate to the enzyme preparation enhanced activity, and saturation was already reached at the lowest tested concentration of 10 μM. The enzyme showed activity in the range of pH 6 to 10 with an optimum at pH 8.5, and in the range of 6°C to 50°C with an optimum at 35°C. The aminotransferase worked best at low salt concentration. FumI activity could be recovered after preincubation at pH 4.0 or higher, but not lower. The aminotransferase was denatured after preincubation at 60°C for 1 h, and the residual activity was also reduced after preincubation at lower temperatures. At optimum conditions, the kinetic parameters K (M) = 1.1 μM and k (cat) = 104/min were determined with 5 mM pyruvate as co-substrate. Based on the enzyme characteristics, a technological application of FumI, in combination with the fumonisin carboxylesterase FumD for hydrolysis of fumonisins, for deamination and detoxification of hydrolyzed fumonisins seems possible, if the enzyme properties are considered.

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.

Valorisation of used cooking oil sludge by codigestion with swine manure

International Nuclear Information System (INIS)

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

2014-01-01

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 4 yield was 326 l/kg VS 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 4 yield obtained was 326 ± 46 l/kg VS feed at an HRT of 50 d, while this value was reduced to 274 ± 43 l/kg VS 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 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

Effect of maize silage addition on biomethane recovery from mesophilic co-digestion of chicken and cattle manure to suppress ammonia inhibition

International Nuclear Information System (INIS)

Yangin-Gomec, Cigdem; Ozturk, Izzet

2013-01-01

Highlights: • Daily biomethane and total energy productions improved 1.2 fold when maize silage is co-digested with the animal wastes. • Heat produced is sufficient for successful mesophilic co-digestion with an energy saving ∼36 × 10 3 kW h with maize silage. • Excess heat up to 16 × 10 3 kW h can be utilized elsewhere in the premises of the biogas plant. • Biogas plants including co-digestion of manure with a suitable co-substrate are becoming net producers of renewable energy. • pH values above 7.4 may cause severe inhibition of methanogenic cultures for an unadapted process to NH 3 . - Abstract: The aim of this study is to evaluate the biogas recovery potential if mesophilic (35 ± 2 °C) anaerobic co-digestion of two different types of manure sources (from chicken and cattle) is applied at a biogas plant. In order to evaluate the improvement in biogas production in the presence of the co-substrate, maize silage is digested together with the animal manure. Results indicated that daily biomethane and total energy (power + heat) productions improved about 1.2 fold when maize silage is co-digested with cattle and chicken wastes. The heat and power energy potentials from the produced biogas were determined using the conversion rates of a CHP unit. Significant energy recovery could be achieved for both cases; i.e. total methane productions were calculated as 5800 and 6580 m 3 /day corresponding to total energy productions of some 45.05 × 10 3 and 51.06 × 10 3 kW h without and with maize silage addition, respectively. A heat analysis was also performed where the resulting biomethane productions were the basis of the heat requirements. Results indicated that the major part of the heating requirements consisted of slurry heating to the operating temperature (in this study 35 °C). When the overall heat requirements are compared to the heat potential from a CHP unit, it is clear that the heat produced is sufficient for successful mesophilic co

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.)

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.

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)

Biological degradation of partially oxidated constituents of stabilized sapropel; Biologischer Abbau teiloxidierter Inhaltsstoffe stabilisierter Faulschlaemme

Energy Technology Data Exchange (ETDEWEB)

Scheminski, A.; Krull, R.; Hempel, D.C. [Technische Univ. Braunschweig (Germany). Inst. fuer Bioverfahrenstechnik

1999-07-01

Partial oxidation of sapropel with ozone destroys the cell walls of microorganisms in sludge and releases the cell constituents. Substances that are not biologically degraded because of the size or structure of their molecules are transformed into smaller, water-soluble and biologically degradable fractions by the reaction with ozone. The experiments aim to render the partially oxidated sewage sludge constituents highly biologically degradable using a minimum of oxidation agents. For the experiments described, stabilized sapropels with low biological activity are used. Hence the ozone is mainly used for the partial oxidation of recalcitrant constituents. (orig.) [German] Durch partielle Oxidation von Faulschlaemmen mit Ozon werden die Zellwaende der Mikroorganismen im Schlamm zerstoert und die Zellinhaltsstoffe freigesetzt. Dabei werden Substanzen, die aufgrund ihrer Molekuelgroesse oder -struktur biologisch nicht abgebaut werden, durch die Reaktion mit Ozon in kleinere, wasserloesliche und biologisch abbaubare Bruchstuecke ueberfuehrt. Ziel der Versuche ist es, durch den Einsatz moeglichst geringer Mengen an Oxidationsmitteln eine hohe biologische Abbaubarkeit der teiloxidierten Klaerschlamminhaltsstoffe zu erreichen. Fuer die hier vorgestellten Experimente wurden stabilisierte Faulschlaemme mit geringer biologischer Aktivitaet eingesetzt. Dadurch wird das Ozon vorwiegend zur Teiloxidation recalcitranter Inhaltsstoffe genutzt. (orig.)

Vancomycin analogues containing monosaccharides exhibit improved antibiotic activity: a combined one-pot enzymatic glycosylation and chemical diversification strategy.

Science.gov (United States)

Thayer, Desiree A; Wong, Chi-Huey

2006-09-18

Many natural products contain carbohydrate moieties that contribute to their biological activity. Manipulation of the carbohydrate domain of natural products through multiple glycosylations to identify new derivatives with novel biological activities has been a difficult and impractical process. We report a practical one-pot enzymatic approach with regeneration of cosubstrates to synthesize analogues of vancomycin that contain an N-alkyl glucosamine, which exhibited marked improvement in antibiotic activity against a vancomycin-resistant strain of Enterococcus.

Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins

OpenAIRE

Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

2014-01-01

Background The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. Results In this study, a draft genome sequence of D. biacutus ...

Comparison of Rumen and Manure Microbiomes and Implications for the Inoculation of Anaerobic Digesters

OpenAIRE

Emine Gozde Ozbayram; Orhan Ince; Bahar Ince; Hauke Harms; Sabine Kleinsteuber

2018-01-01

Cattle manure is frequently used as an inoculum for the start-up of agricultural biogas plants or as a co-substrate in the anaerobic digestion of lignocellulosic feedstock. Ruminal microbiota are considered to be effective plant fiber degraders, but the microbes contained in manure do not necessarily reflect the rumen microbiome. The aim of this study was to compare the microbial community composition of cow rumen and manure with respect to plant fiber-digesting microbes. Bacterial and methan...

Pyrene degradation by yeasts and filamentous fungi.

Science.gov (United States)

Romero, M Cristina; Salvioli, Mónica L; Cazau, M Cecilia; Arambarri, A M

2002-01-01

The saprotrophic soil fungi Fusarium solani (Mart.) Sacc., Cylindrocarpon didymum (Hartig) Wollenw, Penicillium variabile Sopp. and the yeasts Rhodotorula glutinis (Fresenius) Harrison and Rhodotorula minuta (Saito) Harrison were cultured in mineral medium with pyrene. The remaining pyrene concentrations were periodically determined during 20 incubation days, using HPLC. To assess the metabolism of pyrene degradation we added 0.1 microCi of [4,5,9,10] 14C-pyrene to each fungi culture and measured the radioactivity in the volatile organic substances, extractable, aqueous phase, biomass and 14CO2 fractions. The assays demonstrated that F. solani and R. glutinis metabolized pyrene as a sole source of carbon. Differences in their activities at the beginning of the cultures disappeared by the end of the experiment, when 32 and 37% of the original pyrene concentration was detected, for the soil fungi and yeasts, respectively. Among the filamentous fungi, F. solani was highly active and oxidized pyrene; moreover, small but significant degradation rates were observed in C. didymum and P. variahile cultures. An increase in the 14CO2 evolution was observed at the 17th day with cosubstrate. R. glutinis and R. minuta cultures showed similar ability to biotransform pyrene, and that 35% of the initial concentration was consumed at the end of the assay. The same results were obtained in the experiments with or without glucose as cosubstrate.

Selective oxidation of trimethylolpropane to 2,2-bis(hydroxymethyl)butyric acid using growing cells of Corynebacterium sp. ATCC 21245.

Science.gov (United States)

Sayed, Mahmoud; Dishisha, Tarek; Sayed, Waiel F; Salem, Wesam M; Temerk, Hanan A; Pyo, Sang-Hyun

2016-03-10

Multifunctional chemicals including hydroxycarboxylic acids are gaining increasing interest due to their growing applications in the polymer industry. One approach for their production is a biological selective oxidation of polyols, which is difficult to achieve by conventional chemical catalysis. In the present study, trimethylolpropane (TMP), a trihydric alcohol, was subjected to selective oxidation using growing cells of Corynebacterium sp. ATCC 21245 as a biocatalyst and yielding the dihydroxy-monocarboxylic acid, 2,2-bis(hydroxymethyl)butyric acid (BHMB). The study revealed that co-substrates are crucial for this reaction. Among the different evaluated co-substrates, a mixture of glucose, xylose and acetate at a ratio of 5:5:2 was found optimum. The optimal conditions for biotransformation were pH 8, 1v/v/m airflow and 500rpm stirring speed. In batch mode of operation, 70.6% of 5g/l TMP was converted to BHMB in 10 days. For recovery of the product the adsorption pattern of BHMB to the anion exchange resin, Ambersep(®) 900 (OH(-)), was investigated in batch and column experiments giving maximum static and dynamic binding capacities of 135 and 144mg/g resin, respectively. BHMB was separated with 89.7% of recovery yield from the fermentation broth. The approach is applicable for selective oxidation of other highly branched polyols by biotransformation. Copyright © 2016 Elsevier B.V. All rights reserved.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.)

Rescue of TET2 Haploinsufficiency in Myelodysplastic Syndrome Patients Using Turbo Cosubstrate

Science.gov (United States)

2017-07-01

prevalent in a number of myeloid malignancies such as MDS-myeloproliferative neoplasms (MDS-MPN) and acute myeloid leukemia derived from MDS and MDS...Myelodysplastic syndromes (MDS), MDS-myeloproliferative neoplasms (MDS-MPN), Acute myeloid leukemia (AML), 5-methylcytosine (5mC), Mutation...normal initially, with age, develop diverse myeloid malignancies similar to humans. The objective in this project is to develop effective strategies

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...

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

SAFIRA project B.3.3: in-situ-treatment of contaminated ground water by catalytic oxidation. Final report; Sanierungsforschung in regional kontaminierten Aquiferen (SAFIRA). Projekt B.3.3: In situ-Behandlung von kontaminierten Grundwaessern durch katalytische Oxidation. Teilvorhaben 1: Untersuchungen im Labormassstab. Teilvorhaben 2: Tests in der bench-scale-Anlage und Teilvorhaben 3: Die Erprobung in der Pilotanlage am Modellstandort. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Hofmann, J.; Haentzschel, D.; Freier, U.; Wecks, M.

2003-06-27

A new technology for treatment of contaminated ground water was developed. In this process heterogeneous catalysts (full metal catalyst, mixed oxide catalyst or iron-containing zeolites) in combination with hydrogen peroxide are used. In the reactor catalytic oxidation and aerob biological degradation occur simultaneously. A complete degradation of chlorobenzene was observed in a bench-scale-equipment (2 liter) and also in the pilot plant at the model site located in Bitterfeld (30 liter reactor). The technology can be applied to the ground and waste water treatment. (orig.) [German] Fuer die Behandlung von Grundwaessern, die mit organischen Schadstoffen belastet sind, wurde ein neuartiges Verfahren entwickelt. Bei der katalytischen Oxidation werden heterogene Katalysatoren in Form von Vollmetall-, Mischoxid- und Traegerkatalysatoren in Verbindung mit Wasserstoffperoxid als Oxidationsmittel eingesetzt. In den Katalysereaktoren laufen die heterogen-katalytische Oxidation und der aerob-biologische Abbau nebeneinander ab. Es werden synergistische Effekte erzielt. Mit dem Verfahren wurde in einer bench-scale-Angle (2 Liter) und in der Pilotanlage am Modellstandort in Bitterfeld (30 l Reaktor) der Schadstoff Chlorbenzol vollstaendig umgesetzt. Das Verfahren kann zur Grund- und Abwasserbehandlung eingesetzt werden. (orig.)

The therapeutic use of radon; Radon als Heilmittel

Energy Technology Data Exchange (ETDEWEB)

Deetjen, P [Innsbruck Univ. (Austria). Inst. fuer Physiologie und Balneologie

1995-09-01

Spas with a somewhat elevated concentration of Radon{sup 222} (between 300 and 3000 Bq/l) are described to achieve good clinical results in the treatment of chronic rheumatic diseases. Recently a prospective randomized doubel-blind-study proved the pain reducing efficacy of Radon therapy in patients with cervical pain. Studies in experimental animal models have accumulated remarkable data in tissues and organs that provide a rationale to explain the observed effects of Radon therapy in patients. (orig.) [Deutsch] In verschiedenen europaeischen und asiatischen Laendern werden oft schon seit vielen Jahrhunderten Quellen als besonders heilkraeftig beschrieben, die eine etwas erhoehte Aktivitaet an Radon{sup 222} aufweisen (etwas zwischen 300 und 3000 Bq/l). Neuerdings liegt auch eine prospektive randomisierte Doppelblind-Studie vor, die den klinischen Nachweis der Schmerzlinderung durch eine Radonkur erbringt. In tierexperimentellen Untersuchungen wurden unter Radonexposition zahlreiche stimulierende Effekte auf Zellstoffwechsel, Immunabwehr, Abbau toxischer Radikale, DNA-Reparatur-Systeme oder Synthese von Mediatorsubstanzen gemessen, die rationale Ansaetze fuer das Verstaendnis der Wirkung einer Radonexposition im niedrigen Dosisbereich ergeben. (orig.)

A conformational investigation of propeptide binding to the integral membrane protein γ-glutamyl carboxylase using nanodisc hydrogen exchange mass spectrometry

DEFF Research Database (Denmark)

Parker, Christine H; Morgan, Christopher R; Rand, Kasper Dyrberg

2014-01-01

of carboxylation co-substrates. Noteworthy modifications in HX of GGCX were prominently observed in GGCX peptides 491-507 and 395-401 upon pCon association, consistent with regions previously identified as sites for propeptide and glutamate binding. Several additional protein regions exhibited minor gains...... in solvent protection upon propeptide incorporation, providing evidence for a structural reorientation of the GGCX complex in association with VKD carboxylation. The results herein demonstrate that nanodisc-HX MS can be utilized to study molecular interactions of membrane-bound enzymes in the absence...

Mikrobiologische und biochemische Analyse der Fermentationseigenschaften von Lactobacillus paralimentarius AL28 und Lactobacillus plantarum AL30 in Sauerteigen aus Pseudozerealien

OpenAIRE

Vogel, Antje

2011-01-01

Pseudozerealien besitzen kein Gluten und sind daher für Menschen mit Zöliakie von Bedeutung. Es gibt derzeit keine kommerziell erhältlichen Starterkulturen für Sauerteige aus Pseudozerealien. In der vorliegenden Arbeit wurden die Stämme L. paralimentarius AL28 und L. plantarum AL30 in ihrer Eignung als Starterkulturen für Sauerteige aus Pseudozerealien evaluiert. In den Analysen wurden Amaranth und Buchweizen eingesetzt. Die Teige wurden im Labormaßstab bei 30°C und einer Teigausbeute 200...

A review of dark fermentative hydrogen production from biodegradable municipal waste fractions.

Science.gov (United States)

De Gioannis, G; Muntoni, A; Polettini, A; Pomi, R

2013-06-01

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 H2 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 strictly required, claiming for more systematic and comprehensive studies on the subject. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carbonylation as a key reaction in anaerobic acetone activation by Desulfococcus biacutus.

Science.gov (United States)

Gutiérrez Acosta, Olga B; Hardt, Norman; Schink, Bernhard

2013-10-01

Acetone is activated by aerobic and nitrate-reducing bacteria via an ATP-dependent carboxylation reaction to form acetoacetate as the first reaction product. In the activation of acetone by sulfate-reducing bacteria, acetoacetate has not been found to be an intermediate. Here, we present evidence of a carbonylation reaction as the initial step in the activation of acetone by the strictly anaerobic sulfate reducer Desulfococcus biacutus. In cell suspension experiments, CO was found to be a far better cosubstrate for acetone activation than CO2. The hypothetical reaction product, acetoacetaldehyde, is extremely reactive and could not be identified as a free intermediate. However, acetoacetaldehyde dinitrophenylhydrazone was detected by mass spectrometry in cell extract experiments as a reaction product of acetone, CO, and dinitrophenylhydrazine. In a similar assay, 2-amino-4-methylpyrimidine was formed as the product of a reaction between acetoacetaldehyde and guanidine. The reaction depended on ATP as a cosubstrate. Moreover, the specific activity of aldehyde dehydrogenase (coenzyme A [CoA] acylating) tested with the putative physiological substrate was found to be 153 ± 36 mU mg(-1) protein, and its activity was specifically induced in extracts of acetone-grown cells. Moreover, acetoacetyl-CoA was detected (by mass spectrometry) after the carbonylation reaction as the subsequent intermediate after acetoacetaldehyde was formed. These results together provide evidence that acetoacetaldehyde is an intermediate in the activation of acetone by sulfate-reducing bacteria.

The anaerobic phototrophic metabolism of 3-chlorobenzoate by Rhodopseudomonas palustris

Energy Technology Data Exchange (ETDEWEB)

Kamal, V S

1992-10-09

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

Key factors for achieving profitable biogas production from agricultural waste and sustainable biomass

DEFF Research Database (Denmark)

Molinuevo-Salces, Beatriz; Larsen, Søren U.; Biswas, Rajib

2013-01-01

Based on numerous investigations on increasing the biogas yield of manure, a new concept was developed to increase the economical operation of manure based biogas plants by combining up concentration of manure with a more specific treatment of the recalcitrant lignocellulosic fiber fraction...... by implementing the treatment on the digested solid fraction. Catch crops have been identified as a sustainable co-substrate for biogas production with a high biogas potential. For exploiting this biomass for profitable biogas production, the biomass yield per hectare, harvest costs, TS concentration and specific...

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 ...

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.)

Microbiological sanitation of abandoned armament sites - treatment of TNT-contaminated soils. Sanierung von Ruestungsaltlasten durch mikrobiologische Verfahren: Behandlung TNT-kontaminierter Boeden

Energy Technology Data Exchange (ETDEWEB)

Winterberg, R.; Stoffers, H. (Contracon GmbH, Cuxhaven (Germany))

TNT (trinitrotoluene) is the most commonly used military explosive. It is a hazardous material which has been spread over many abandoned armament sites since its production and processing during Wold War II and the subsequent delaboration and dismantling of TNT production plants. The harmful effect of this explosive on man and on the environment calls for the sanitation of TNT-contaminated sites. The microbiological method is among the techniques applied to clean TNT-contaminated soils and waters. (orig.).

Recalcitrant Compounds Removal in Raw Leachate and Synthetic Effluents Using the White-Rot Fungus Bjerkandera adusta

Directory of Open Access Journals (Sweden)

Alessandra Bardi

2017-10-01

Full Text Available Recalcitrant compounds limit the efficiency of conventional biological processes for wastewater treatment, representing one of the major issues in the field. This study focused on the treatment of three effluents with White-Rot-Fungus (WRF Bjerkandera adusta MUT 2295 in batch tests, with biomass cultivated in attached form on polyurethane foam cubes (PUFs to test its efficiency in the removal of the target effluents’ recalcitrant fraction. Treatment efficiency of B. adusta was evaluated on landfill leachate (Canada and two solutions containing synthetic recalcitrant compounds, which were prepared with tannic and humic acid. Chemical Oxygen Demand (COD and color removal, the production of manganese peroxidases, and the consumption of a co-substrate (glucose were monitored during the experiment. Biological Oxygen Demand (BOD5 and fungal dry weight were measured at the beginning and at the end of the experiment. After co-substrate addition, effluent COD was 2300 ± 85, 2545 ± 84, and 2580 ± 95 (mg/L in raw leachate and tannic and humic acids, respectively. COD removal of 48%, 61%, and 48% was obtained in raw leachate and in the synthetic effluents containing tannic and humic acids, respectively. Color removal of 49%, 25%, and 42% was detected in raw leachate and in tannic and humic acid solutions, respectively. COD and color removals were associated with the increase of fungal dry weight, which was observed in all the trials. These results encourage the use of the selected fungal strain to remove tannic acid, while further investigations are required to optimize leachate and humic acid bioremediation.

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.

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.)

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.

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.

Agricultural biogas. Intermediate assessment - Biogas Mission. The Energivie Program - Projects of development of farm-based methanization. Site selection, Visits of installations, Consultation of installers

International Nuclear Information System (INIS)

Maurer, Michel

2005-06-01

A first document presents Alsace pilot projects: technical and economic recalls, site pre-selection, project leader, description of the mobilisation of lipid co-substrates (interest of fats, modalities), regulatory context (for biogas production, electric energy supply and digestate use). It also presents installer companies which have been consulted for these projects. Another document proposes technical and economical analyses of proposals made by installers, and an analysis of deadlocking points for these pilot projects. Technical, economic, and environmental elements, as well as those dealing with installation management, costs and construction delays to be provided by the consulted company are indicated and commented

Crystal structures of the methyltransferase and helicase from the ZIKA 1947 MR766 Uganda strain

Energy Technology Data Exchange (ETDEWEB)

Bukrejewska, Malgorzata; Derewenda, Urszula; Radwanska, Malwina; Engel, Daniel A.; Derewenda, Zygmunt S.

2017-08-15

Two nonstructural proteins encoded byZika virusstrain MR766 RNA, a methyltransferase and a helicase, were crystallized and their structures were solved and refined at 2.10 and 2.01 Å resolution, respectively. The NS5 methyltransferase contains a boundS-adenosyl-L-methionine (SAM) co-substrate. The NS3 helicase is in the apo form. Comparison with published crystal structures of the helicase in the apo, nucleotide-bound and single-stranded RNA (ssRNA)-bound states suggests that binding of ssRNA to the helicase may occur through conformational selection rather than induced fit.

Development of a method for direct biological removal of ammonium to nitrogen in treatment of waste waters of the anaerobic sludge digestion - deammonification. Final report; Entwicklung eines Verfahrens zur direkten biologischen Umsetzung von Ammonium zu Stickstoff bei der Behandlung von Abwaessern der Anaerob-Klaerschlammfaulung - Deammonifikation. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Rosenwinkel, K.H.; Seyfried, C.F.; Kunst, S.; Diekmann, H.; Hippen, A.; Helmer, C.; Scholten, E.

2001-07-01

initiation tests were run. Accompanying batch-tests and micro-biological analyses served mainly for the kinetic examination of the metabolisms, that is for the determination of the conversion performances and for the basic analysis of the relevant metabolism ways and the participating micro-organisms. (orig.) [German] Die Stickstoffelimination in kommunalen und industriellen Abwaessern spielt in der Abwasserreinigung weiterhin eine bedeutende Rolle, zumal mit der Abwasserverordnung (AbwV) von 1997 einige Veraenderungen bei den Anforderungen und Regelungen hinsichtlich der Schad- und Naehrstoffentfernung vorgenommen wurden. Da gerade die Stickstoffentfernung oftmals einen erheblichen Kostenfaktor bei der Abwasserreinigung darstellt, insbesondere wenn es um die (Mit-)Behandlung hoch stickstoffbelasteter Teilstroeme geht, ist man stetig auf der Suche nach wirtschaftlichen Behandlungskonzepten. Im Rahmen des Forschungsvorhabens wurde das Verfahren der Deammonifikation entwickelt, d.h. die Prozessfolge aus aerober Nitritation und anoxischer Ammoniumoxidation ('biologische Komproportionierung' von Ammonium und Nitrit zu molekularem Stickstoff), die komplett auf den Stoffwechselprozessen autotropher Mikroorganismen beruht, wodurch sich vor allem Einsparpotentiale hinsichtlich des Kohlenstoffbedarfes ergeben. Aufgrund des verkuerzten aeroben Oxidationsschrittes und bei Anwendung der Biofilmtechnologie lassen sich zudem Sauerstoffbedarf und Reaktionsvolumen reduzieren. Im Hinblick auf einen gezielten verfahrenstechnischen Einsatz der Deammonifikation waren im Rahmen der Forschungsarbeiten die prozessbestimmenden Einflussgroessen zu bestimmen und geeignete Verfahrenstechniken und Verfahrensfuehrungen naeher zu ueberpruefen. Hierzu wurden ausgehend von gross- und pilottechnischen Untersuchungen und Erkenntnissen unter Beruecksichtigung (mikro-)biologischer Zusammenhaenge die wesentlichen Randbedingungen zur Realisierung sowie das Betriebsverhalten der autotrophen

Interlaboratory research project: behaviour of microorganisms and viruses during drinking water conditioning. Partial project 2: Campylobacter and Yersinia. Final report; Verhalten von Mikroorganismen und Viren bei der Trinkwasseraufbereitung. Teilvorhaben 2: Campylobacter und Yersinia. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Schulze, E.; Feuerpfeil, I.; Vobach, V.

1997-09-01

responsible for enteritis. Their incidence in crude water, and their behaviour during drinking water conditioning is investigated in this project. (orig./AJ) [Deutsch] Die noch zu Zeiten Robert Kochs auf den Genuss des Trinkwassers zurueckzufuehrenden Erkrankungen wie Ruhr, Typhus oder Cholera spielen bei uns seit langem keine Rolle mehr. Sichergestellt wurde dies durch moderne Aufbereitungsverfahren und die in der Trinkwasserverordnung festgelegte Ueberwachung des Trinkwassers, die in hygienisch-mikrobiologischer Hinsicht auf dem Indikatorsystem beruht. Das Indikatorsystem wurde entwickelt unter den Bedingun Bedingungen der Nutzung von Waessern aus geschuetzten Wasservorkommen und einer Aufbereitung mittels Langsamfiltration. In neuerer Zeit hat sich die Situation aber dahingehend geaendert, dass in verstaerktem Masse nicht optimal geschuetzte Wasservorkommen genutzt werden muessen, deren Wasser mit immer hoeheren technischen Anforderungen aufbereitet werden muss. Erschwerend kommt hinzu, dass durch neue mikrobiologische und molekularbiologische Nachweisverfahren weitere durch das Wasser uebertragbare Krankheitserreger nachgewiesen wurden, ueber deren Verhalten bei der Trinkwasseraufbereitung kaum Erfahrungen vorliegen und fuer die auch die Gueltigkeit des Indikatorprinzips untersucht werden muss. Einige dieser Mikroorganismen sind zudem sehr chlorresistent (z.B. Parasitendauerformen) und auch mit modernen Aufbereitungsverfahren, wie der Ozonung oder der UV-Desinfektion, nur unzureichend zu eliminieren. Beobachtet wird auch seit einigen Jahren eine erhoehte Anfaelligkeit bestimmter Bevoelkerungsgruppen (Immunsupprimierte, Allergiker, Krebs- und Aidspatienten) gegenueber potentiell pathogenen Mikroorganismen und opportunistischen Erregern, die mit dem Wasser in Verbindung gebracht werden koennen. 1993 veroeffentlichte die WHO in den `Guidelines for Drinking Water Quality` eine Zusammenstellung der moeglichen Krankheitserreger im Trinkwasser mit Angaben zu ihrer Herkunft und

The principle of proportionality in water pollution control during mine flooding; Gewaesserguetewirtschaftliche Beurteilungskriterien bei der Grubenflutung

Energy Technology Data Exchange (ETDEWEB)

Reincke, H. [WEG Wasserguetestelle Elbe, Hamburg (Germany)

2001-07-01

The Wismut remediation project comprised the sanitation of large surfaces of contaminated land in Saxony and Thuringia. About 1,400 km of underground mines and 56 shafts were flooded. The contribution presents a critical discussion of the potential and limits of the flooding process and its economic aspects in consideration of legal specifications. [German] Das Wismut-Sanierungsprojekt beinhaltet die Sanierung der grossflaechig radioaktiv kontaminierten Wismut-Altlasten in Sachsen und Thueringen mit dem Ziel die Uranerzbergbau- und -aufbereitungsbetriebe stillzulegen und die Betriebsflaechen zu sanieren, um sie wieder nutzbar zu machen. Ein wesentlicher Schwerpunkt besteht dabei in der Verwahrung und Flutung vorhandener Gruben, die fuer den untertaegigen Abbau der Erze genutzt wurden und aus rund 1.400 km offenen Grubenbauen und 56 Tagesschaechten bestehen. Dieses weitverzweigte untertaegige Netz von Stollen, Schaechten und Kammern sollte moeglichst rasch ausser Betrieb genommen und fuer die Flutung (Endverwahrung) vorbereitet werden. Dabei stellt die Flutung die umweltvertraeglichste, technisch sicherste und zugleich kostenguenstigste Sanierungsvariante dar. Die Moeglichkeiten und Grenzen zur Beanspruchung der oeffentlichen Vorflut fuer die Grubenwaesser unter Wuerdigung oekonomisch vertretbarer Loesungen im wasserrechtlichen Vollzug werden im Folgenden einer kritischen Betrachtung unterzogen und zur Diskussion gestellt. (orig.)

Microbial degradation. Mass transfer in the system pollutant - water - sediment; Mikrobieller Abbau. Massentransfer im System Schadstoff - Wasser - Sediment

Energy Technology Data Exchange (ETDEWEB)

Tiehm, Andreas [Technologiezentrum Wasser (TZW), Karlsruhe (Germany). Abt. Umweltbiotechnologie und Altlasten; Kranzioch, Irene; Stoll, Claudia

2011-09-15

The microbial degradation of pollutants in the aquatic environment essentially is influenced by the prevailing redox conditions and mass exchange processes (bioavailability). Within a new project, the Technologiezentrum Wasser TZW (Karlsruhe, Federal Republic of Germany) deals with the microbial conversion under dynamic conditions such as those expected in the area of the Three Gorges Dam at the Yangtze River. In particular, molecular-biological methods (PCR, polymerase chain reaction and DGGE Denatured gradient gel electrophoresis) are used for a targeted monitoring and further developed. The focus of the investigation initially focuses on the degradation of halogenated substances which are used as main substances for understanding the mass exchange between sediment and water as well as the microbial conversion processes. An enhanced understanding of the process and the compilation of the dynamic sales performance can be defined as a target.

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

resistant bacteria were reduced in the anaerobic samples in the beginning of the study but increased towards the end of it. The opposite pattern was observed in the aerobic samples, with a growth in the beginning followed by a reduction. During the anaerobic digestion tetracycline resistant bacteria showed......The aim of this study was to compare the effect of mesophilic anaerobic digestion with aerobic storage on the survival of selected indigenous microorganisms and microbial groups in blackwater, including the effect of addition of Greenlandic Halibut and shrimp offal. The methane yield...... of the different substrate mixtures was determined in batch experiments to study possible correlation between methanogenic activity in the anaerobic digesters and reduction of indigenous microorganisms in the blackwater. By the end of the experiments a recovery study was conducted to determine possible injury...

Nitrogen losses and chemical parameters during co-composting of solid wastes and liquid pig manure.

Science.gov (United States)

Vázquez, M A; de la Varga, D; Plana, R; Soto, M

2017-07-04

The aim of this research was to study nitrogen losses during the treatment of the liquid fraction (LF) of pig manure by co-composting and to establish the best conditions for compost production with higher nitrogen and low heavy metal contents. Windrows were constituted with the solid fraction (SF) of pig manure, different organic waste (SF of pig manure, sawdust and grape bagasse) as co-substrate and Populus spp. wood chips as bulking material and watered intensely with the LF. Results show that nitrogen losses ranged from 30% to 66% of initial nitrogen and were mainly governed by substrate to bulking mass ratio and liquid fraction to substrate (LF/S) ratio, and only secondarily by operational parameters. Nitrogen losses decreased from 55-65% at low LF/S ratios (1.7-1.9 m 3 /t total solids (TS)) to 30-39% at high LF/S ratios (4.4-4.7 m 3 /t TS). Therefore, integrating the LF in the composting process at high LF/S ratios favoured nitrogen recovery and conservation. Nitrogen in the fine fraction (ranging from 27% to 48% of initial nitrogen) was governed by operational parameters, namely pH and temperature. Final compost showed low content in most heavy metals, but Zn was higher than the limits for compost use in agriculture. Zn content in the obtained compost varied from 1863 to 3269 mg/kg dm, depending on several factors. The options for obtaining better quality composts from the LF of pig manure are selecting co-substrates with low heavy metal content and using them instead of the SF of pig manure.

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.

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

, an improvement of 1.46 times compared to manure alone. Adaptation to OSR was observed, and no ammonia or volatile fatty acid-mediated inhibition was detected. The results prove that it is feasible to use catch crops as co-substrate for manure-based biogas production, obtaining a stable process with significantly...... CH4/g volatile solids (VS) were obtained for OSR and IR in co-digestion, respectively. OSR co-digestion was chosen for semi-continuous reactor experiments. The addition of 50 % of OSR to manure (on VS basis) in semi-continuous anaerobic digestion resulted in a methane yield of 348 ml CH4/g VS...

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)

Degradation of organic pollutants in the groundwater by mean of heterogeneous catalytic oxidation and a combined process of catalytic oxidation and aerobic biological degradation; Abbau von organischen Schadstoffen im Grundwasser durch heterogen-katalytische Oxidation und die Verfahrenskombination katalytische Oxidation mit aerob-biologischem Abbau

Energy Technology Data Exchange (ETDEWEB)

Hofmann, J.; Freier, U.; Wecks, M.; Haentzschel, D. [Inst. fuer Nichtklassische Chemie e.V. an der Univ. Leipzig, Leipzig (Germany)

2004-07-01

This project formed part of the SAFIRA joint project (Remediation research in regionally contaminated aquifers), which was coordinated by the project division on ''Post-industry and post-mining landscapes'' of Leizig-Halle Environmental Research Centre. The purpose of the present project was to develop various in situ methods of groundwater remediation and test them on the Bitterfeld model site. The project was focussed on developing a groundwater treatment method on the basis of the oxidative catalytic degradation of the organic pollutants. [German] Das Vorhaben war in den SAFIRA-Projektverbund (Sanierungsforschung in regional kontaminierten Aquiferen), das vom Projektbereich Industrie- und Bergbaufolgelandschaften des Umweltforschungszentrums Leipzig-Halle koordiniert wurde, eingebunden. Innerhalb dieses Vorhabens sollten unterschiedliche in-situ Methoden zur Grundwassersanierung entwickelt und am Modellstandort in Bitterfeld getestet werden. Der Schwerpunkt des Vorhabens bestand in der Entwicklung einer Grundwasserbehandlungstechnologie auf der Basis des oxidativ katalytischen Abbaus der organischen Schadstoffe. (orig.)

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.)

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.

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)

1997-12-31

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)

South African hardcoal production, uses and the environment

Energy Technology Data Exchange (ETDEWEB)

Scholtz, E.G. [Ingwe Coal Corporation Limited, Johannesburg (South Africa). Operations and Projects

1997-12-11

Initial legislation in 1912 and subsequently in 1956 was not effective enough to prevent pollution of river and ground water due to mining. Only in 1980 was effective legislation enacted to control water pollution. Until 1991, most of the coal mines were privately owned and were operated in compliance with regulations made by the relevant supervisory authority and the President`s Council. The new Minerals Act became effective in 1991. One of the basic provisions of the Act requires submission and approval of an Environmental Management Progress Report (EMPR) by mine owners prior to licensing of mining activities. (Orig./CB) [Deutsch] Die Gesetze von 1912 und spaeter von 1956 erwiesen sich als nicht wirksam genug, um die durch den Bergbau verursachte Verschmutzung von Fluessen und Grundwasser zu verhindern. Erst im Jahr 1980 wurde eine effektive Gesetzgebung eingefuehrt, um die Wasserverschmutzung zu bekaempfen. Bis zum Jahr 1991 wurden Zechen weitgehend in Selbstverantwortung gefuehrt, indem sie sich auf Richtlinien stuetzten, die durch die Bergbehoerde und die President`s Council (Praesidentenkammer) erlassen worden waren; im Jahr 1991 erging der neue `Minerals Act`. Dieses Gesetz sieht vor, dass der Abbau nur genehmigt wird, wenn ein umfangreicher Fortschrittsbericht fuer Umweltmanagement (EMPR) eingereicht und genehmigt wird. (orig./HS)

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)

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. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

N-terminus determines activity and specificity of styrene monooxygenase reductases.

Science.gov (United States)

Heine, Thomas; Scholtissek, Anika; Westphal, Adrie H; van Berkel, Willem J H; Tischler, Dirk

2017-12-01

Styrene monooxygenases (SMOs) are two-enzyme systems that catalyze the enantioselective epoxidation of styrene to (S)-styrene oxide. The FADH 2 co-substrate of the epoxidase component (StyA) is supplied by an NADH-dependent flavin reductase (StyB). The genome of Rhodococcus opacus 1CP encodes two SMO systems. One system, which we define as E1-type, displays homology to the SMO from Pseudomonas taiwanensis VLB120. The other system, originally reported as a fused system (RoStyA2B), is defined as E2-type. Here we found that E1-type RoStyB is inhibited by FMN, while RoStyA2B is known to be active with FMN. To rationalize the observed specificity of RoStyB for FAD, we generated an artificial reductase, designated as RoStyBart, in which the first 22 amino acid residues of RoStyB were joined to the reductase part of RoStyA2B, while the oxygenase part (A2) was removed. RoStyBart mainly purified as apo-protein and mimicked RoStyB in being inhibited by FMN. Pre-incubation with FAD yielded a turnover number at 30°C of 133.9±3.5s -1 , one of the highest rates observed for StyB reductases. RoStyBart holo-enzyme switches to a ping-pong mechanism and fluorescence analysis indicated for unproductive binding of FMN to the second (co-substrate) binding site. In summary, it is shown for the first time that optimization of the N-termini of StyB reductases allows the evolution of their activity and specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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...... (up to 568%), but at expense of increasing climate change (through LUC), marine eutrophication, and land use. Codigestion with wastes or residues like roadside grass gave the best environmental performance.......-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...

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.

Dismantling of the reactor block of the FRJ-1 research reactor (MERLIN); Abbau des Reaktorblocks des Forschungsreaktors FRJ-1 (MERLIN)

Energy Technology Data Exchange (ETDEWEB)

Stahn, B.; Matela, K.; Zehbe, C. [Forschungszentrum Juelich GmbH (Germany); Poeppinghaus, J. [Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Cremer, J. [Siempelkamp Nukleartechnik GmbH, Heidelberg (Germany)

2003-07-01

By the end of 1998 the complete secondary cooling system and the major part of the primary cooling system were dismantled. Furthermore, the experimental devices, including a rabbit system conceived as an in-core irradiation device, were disassembled and disposed of. In total, approx. 65 t of contaminated and/or activated material as well as approx. 70 t of clearance-measured material were disposed of within the framework of these activities. The dismantling of the coolant loops and experimental devices was followed in 2000 by the removal of the reactor tank internals and the subsequent draining of the reactor tank water. The reactor tank internals were essentially the core support plate, the core box, the flow channel and the neutron flux bridges (s. Fig. 2, detailed reactor core). All components consisted of aluminium, the connecting elements such as bolts and nuts, however, of stainless steel. Due to the high activation of the core internals, disassembly had to be remotely controlled under water. All removal work was carried out from a tank intermediate floor (s. Fig. 2). These activities, which served for preparing the dismantling of the reactor block, were completed in summer 2001. The waste parts arising were transferred to the Service Department for Decontamination of the Research Centre. This included approx. 2.5 t of waste parts with a total activity of approx. 8 x 10{sup 11} Bq. (orig.)

Modulating NAD+ metabolism, from bench to bedside.

Science.gov (United States)

Katsyuba, Elena; Auwerx, Johan

2017-09-15

Discovered in the beginning of the 20 th century, nicotinamide adenine dinucleotide (NAD + ) has evolved from a simple oxidoreductase cofactor to being an essential cosubstrate for a wide range of regulatory proteins that include the sirtuin family of NAD + -dependent protein deacylases, widely recognized regulators of metabolic function and longevity. Altered NAD + metabolism is associated with aging and many pathological conditions, such as metabolic diseases and disorders of the muscular and neuronal systems. Conversely, increased NAD + levels have shown to be beneficial in a broad spectrum of diseases. Here, we review the fundamental aspects of NAD + biochemistry and metabolism and discuss how boosting NAD + content can help ameliorate mitochondrial homeostasis and as such improve healthspan and lifespan. © 2017 The Authors.

Acetylation of spermidine and methylglyoxal bis(guanylhydrazone) in baby-hamster kidney cells (BHK-21/C13).

Science.gov (United States)

Wallace, H M; Nuttall, M E; Robinson, F C

1988-01-01

Treatment of BHK-21/C13 cells with methylglyoxal bis(guanylhydrazone) (MGBG) induced the cytosolic form of spermidine N1-acetyltransferase. It stabilized the enzyme against proteolytic degradation, but the drug did not affect the enzyme activity in vitro. MGBG was itself acetylated by BHK-21/C13 cells, but at only one-tenth the rate at which spermidine was acetylated. Acetylation occurred almost exclusively in the nuclear fraction. The product was identified as N-acetyl-MGBG by h.p.l.c., by using [3H]acetyl-CoA and [14C]MGBG as co-substrates. The results suggest that the acetylation of MGBG by BHK-21/C13 cells occurs by a different acetyltransferase enzyme from that which acetylates spermidine. PMID:3421945

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.

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

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......, particularly concerning bioenergy production. We compare the use of allocation of cocoa production impacts and system expansion that includes cocoa production as possible methods to manage multifunctionality of inputs. Inassessments of residue-based production, we recommend using the latter method. Applying......Agro-industrial businesses often have easy access to agricultural and processing residues with whichthey may reduce costs and pollution by integrating their production with bioenergy production. In regionswith unreliable power supply, on-site electricity generation is a means to secure stable...

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.

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...

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.

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)

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

A review of dark fermentative hydrogen production from biodegradable municipal waste fractions

International Nuclear Information System (INIS)

De Gioannis, G.; Muntoni, A.; Polettini, A.; Pomi, R.

2013-01-01

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 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 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 strictly

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

Stochastic modelling of the economic viability of on-farm co-digestion of pig manure and food waste in Ireland

International Nuclear Information System (INIS)

Dennehy, C.; Lawlor, P.G.; Gardiner, G.E.; Jiang, Y.; Shalloo, L.; Zhan, X.

2017-01-01

Highlights: •Assessed economic viability of on-farm manure mono- and co-digestion. •Assessed three farm sizes: 521 sows; 2607 sows; and 5214 sows. •Mono-digestion of manure alone not economically viable. •Co-digestion viable on small farms as food waste likely to be sourced. •Viability on larger farms dependent on securing sufficient food waste. -- Abstract: The majority of studies analysing the economic potential of biogas systems utilise deterministic models to assess the viability of a system using fixed inputs. However, changes in market conditions can significantly affect the viability of biogas plants, and need to be accounted for. This study assessed the economic potential of undertaking on-farm anaerobic co-digestion of food waste (FW) and pig manure (PM) using both deterministic and stochastic modelling approaches. The financial viability of three co-digestion plants sized to treat PM generated from 521, 2607 and 5214 sow integrated units was assessed. Under current market conditions the largest co-digestion scenario modelled was found to be unviable. Stochastic modelling of four key input variables (FW availability, renewable electricity tariff, gate fees and digestate disposal costs) was undertaken to assess the sensitivity of project viability to changes in market conditions. Due to the high likelihood of accessing sufficient FW, the smallest co-digestion scenario was found to be the least sensitive to any future changes in market conditions. Due to its potential to treat greater amounts of FW than the smallest scenario, a co-digestion plant designed for a 2607 sow farm had the highest revenue generating potential under optimal market conditions; however, it was more sensitive to changes in FW availability than the smaller scenario. This study illustrates the need for farm-based biogas plant projects to secure long-term, stable supplies of co-substrates and to size plants’ capacity based on the availability of the co-substrates which drive

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.)

Environmental Consequences of Pig Slurry Treatment Technologies

DEFF Research Database (Denmark)

ten Hoeve, Marieke

occur during manure storage and after field application. The main emissions are ammonia, nitrous oxide, methane, carbon dioxide, nitrate, phosphorus and odour. Slurry treatment technologies have been and are being developed in order to reduce the environmental impacts of manure. However, it is important...... and excluding biogenic carbon, marine and freshwater eutrophication potential, terrestrial acidification and eutrophication potential, and fossil resource depletion potential. The different types of treatment technologies showed varying environmental profiles, meaning that one type of technology was beneficial...... technology, or co-substrate for anaerobic digestion). With respect to odorous emissions, an LCIA method was developed, but due to a lack of data it proved difficult to include odour in LCA. Regulations appear to have an influence on the environmental impacts of slurry treatment. A decrease in N application...

Environmental Consequences of Future Biogas Technologies based on Separated Slurry

DEFF Research Database (Denmark)

Hamelin, Lorie; Wesnæs, Marianne; Wenzel, Henrik

2011-01-01

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......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...... 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...

Probing the structural basis of oxygen binding in a cofactor-independent dioxygenase.

Science.gov (United States)

Li, Kunhua; Fielding, Elisha N; Condurso, Heather L; Bruner, Steven D

2017-07-01

The enzyme DpgC is included in the small family of cofactor-independent dioxygenases. The chemistry of DpgC is uncommon as the protein binds and utilizes dioxygen without the aid of a metal or organic cofactor. Previous structural and biochemical studies identified the substrate-binding mode and the components of the active site that are important in the catalytic mechanism. In addition, the results delineated a putative binding pocket and migration pathway for the co-substrate dioxygen. Here, structural biology is utilized, along with site-directed mutagenesis, to probe the assigned dioxygen-binding pocket. The key residues implicated in dioxygen trafficking were studied to probe the process of binding, activation and chemistry. The results support the proposed chemistry and provide insight into the general mechanism of dioxygen binding and activation.

Post-translational Introduction of D-Alanine into Ribosomally Synthesized Peptides by the Dehydroalanine Reductase NpnJ.

Science.gov (United States)

Yang, Xiao; van der Donk, Wilfred A

2015-10-07

Ribosomally synthesized peptides are generally limited to L-amino acid building blocks. Given the advantageous properties of peptides containing D-amino acids such as stabilization of certain turns and against proteolytic degradation, methods to introduce D-stereocenters are valuable. Here we report the first in vitro reconstitution and characterization of a dehydrogenase that carries out the asymmetric reduction of dehydroalanine. NpnJA reduces dehydroalanine to D-Ala using NAPDH as cosubstrate. The enzyme displays high substrate tolerance allowing introduction of D-Ala into a range of non-native substrates. In addition to the in vitro reactions, we describe five examples of using Escherichia coli as biosynthetic host for D-alanine introduction into ribosomal peptides. A deuterium-label-based coupled-enzyme assay was used to rapidly determine the stereochemistry of the newly installed alanine.

Degradation of carbazole, dibenzothiophene, and dibenzofuran at low temperature by Pseudomonas sp. strain C3211.

Science.gov (United States)

Jensen, Anne-Mette; Finster, Kai Waldemar; Karlson, Ulrich

2003-04-01

Pseudomonas sp. strain C3211 was isolated from a temperate climate soil contaminated with creosote. This strain was able to degrade carbazole, dibenzothiophene and dibenzofuran at 10 degrees C with acetone as a co-substrate. When dibenzothiophene was degraded by strain C3211, an orange compound, which absorbed at 472 nm, accumulated in the medium. Degradation of dibenzofuran was followed by accumulation of a yellowish compound, absorbing at 462 nm. The temperature optimum of strain C3211 for degradation of dibenzothiophene and dibenzofuran was at 20 to 21 degrees C, while the maximum temperature for degradation was at 27 degrees C. Both compounds were degraded at 4 degrees C. Degradation at 10 degrees C was faster than degradation at 25 degrees C. This indicates that strain C3211 is adapted to life at low temperatures.

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

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......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...

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.)

Environmental pollution caused by coal mining and utilization in China; Umweltbelastungen durch Kohlefoerderung und -nutzung in China

Energy Technology Data Exchange (ETDEWEB)

Bai, Fuchen [Guangdong Ocean Univ., Zhanjiang (China). Dept. of Scientific Research Management

2013-07-15

After the BP Statistical Review of World Energy of 2010 45.6% of coal production and 46.9% of coal consumption in the world in 2009 are accounted for China. The large-scale coal production and use cause major environmental impacts. A large environmental impact is through the emission of some unavoidable reaction products (for example waste gas, waste heat) that affect and damage the ecosystem. A steady influence can lead to long-term climate changes and medium term damage to the ecosystem. Other environmental impacts occur during mining of coal by the change in the water balance and the transformation of the landscape (surface mining, spoil tips). The environmental problems caused by coal mining and utilization can not be ignored in China. [German] Nach der BP-Statistik der Weltenergie 2010 sind 45,6% der Kohleproduktion und 46,9% des Kohleverbrauchs in der Welt im Jahr 2009 auf China entfallen. Die grossangelegte Kohlefoerderung und -verwendung fuehren zu grossen Umweltbelastungen. Eine grosse Umweltbeeinflussung erfolgt durch die Emission von zum Teil unvermeidbaren Umsetzungsprodukten (zum Beispiel Abgas, Abwaerme), die das Oekosystem beeinflussen und schaedigen. Eine stetige Beeinflussung kann langfristig zu den Klimaveraenderungen und mittelfristig zur Schaedigung des Oekosystems fuehren. Weitere Umweltbelastungen erfolgen beim Abbau der Kohle durch die Veraenderung des Wasserhaushalts und durch die Umgestaltung der Landschaft (Tagebau, Abbauhalden). Die Umweltprobleme, die durch die Kohlefoerderung und -nutzung verursacht werden, koennen in China nicht ignoriert werden.

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)

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

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...... 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...

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...

Investigating the Sensitivity of NAD+-dependent Sirtuin Deacylation Activities to NADH

DEFF Research Database (Denmark)

Madsen, Andreas Stahl; Andersen, Christian; Daoud, Mohammad Mahdi

2016-01-01

Protein lysine posttranslational modification by an increasing number of different acyl groups is becoming appreciated as a regulatory mechanism in cellular biology. Sirtuins are class III histone deacylases that use NAD+ as a co-substrate during amide bond hydrolysis. Several studies have...... described the sirtuins as sensors of the NAD+/NADH ratio, but it has not been formally tested for all the mammalian sirtuins in vitro. To address this problem, we first synthesized a wide variety of peptide-based probes, which were used to identify the range of hydrolytic activities of human sirtuins...... to be prone to hydrolytic cleavage by SIRT1-3 and SIRT6, supporting recent findings. We then tested the ability of NADH, ADP-ribose, and nicotinamide to inhibit these NAD+-dependent deacylase activities of the sirtuins. In the commonly used 7-amino-4-methylcoumarin-coupled fluorescence-based assay...

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.

Treatment of spices with ionizing radiation - chemical, organoleptical, microbiological and toxicological analyses. Pt. 1. Behandlung von Gewuerzen mit ionisierenden Strahlen - chemische, organoleptische, mikrobiologische und toxikologische Aspekte

Energy Technology Data Exchange (ETDEWEB)

Schuettler, C; Boegl, W

1984-01-01

In a study of the relevant literature the results of tests on 30 radiation treated spices were evaluated. The tests contain chemical, organoleptical, microbiological and toxicological analyses. Most of the spices were treated with gamma radiation from cobalt-60 sources with doses up to 60 kGy.

Full-scale agricultural biogas plant metal content and process parameters in relation to bacterial and archaeal microbial communities over 2.5 year span.

Science.gov (United States)

Repinc, Sabina Kolbl; Šket, Robert; Zavec, Domen; Mikuš, Katarina Vogel; Fermoso, Fernando G; Stres, Blaž

2018-05-01

A start-up of 4 MW agricultural biogas plant in Vučja vas, Slovenia, was monitored from 2011 to 2014. The start-up was carried out in 3 weeks with the intake of biomass from three operating full-scale 1-2 MW donor agricultural biogas plants. The samples were taken from donor digesters and from two serial digesters during the start-up over the course of 2.5 years. Bacterial and Archaeal microbial communities progressively diverged from the composition of donor digesters during the start-up phase. The rate of change of Bacterial community decreased exponentially over the first 2.5 years as dynamics within the first 70 days was comparable to that of the next 1.5 years, whereas approximately constant rate was observed for Archaea. Despite rearrangements, the microbial communities remained functionally stable and produced biogas throughout the whole 2.5 years of observation. All systems parameters measured were ordered according to their Kernel density (Gaussian function) ranging from the most dispersed (substrate categories used as cosubstrates, quantities of each cosubstrate, substate dry and volatile matter, process parameters) towards progressively least dispersed (trace metal and ion profiles, aromatic-polyphenolic compounds, biogas plant functional output (energy)). No deficiency was detected in trace metal content as the distribution of metals and elements fluctuated within the suggested limits for biogas over 2.5 year observation. In contrast to the recorded process variables, Bacterial and Archaeal microbial communities exhibited directed changes oriented in time. Variation partitioning showed that a large fraction of variability in the Bacterial and Archaeal microbial communities (55% and 61%, respectively) remained unexplained despite numerous measured variables (n = 44) and stable biogas production. Our results show that the observed reorganization of microbial communities was not directly associated with impact on the full-scale biogas reactor

New psychoactive substances: Studies on the metabolism of XLR-11, AB-PINACA, FUB-PB-22, 4-methoxy-α-PVP, 25-I-NBOMe, and meclonazepam using human liver preparations in comparison to primary human hepatocytes, and human urine.

Science.gov (United States)

Richter, Lilian H J; Maurer, Hans H; Meyer, Markus R

2017-10-05

New psychoactive substances (NPS) are an increasing problem in clinical and forensic toxicology. The knowledge of their metabolism is important for toxicological risk assessment and for developing toxicological urine screenings. Considering the huge numbers of NPS annually appearing on the market, metabolism studies should be realized in a fast, simple, cost efficient, and reliable way. Primary human hepatocytes (PHH) were recommended to be the gold standard for in vitro metabolism studies as they are expected to contain natural enzyme clusters, co-substrates, and drug transporters. In addition, they were already successfully used for metabolism studies of NPS. However, they also have disadvantages such as high costs and limited applicability without special equipment. The aims of the present study were therefore first to investigate exemplarily the phase I and phase II metabolism of six NPS (XLR-11, AB-PINACA, FUB-PB-22, 4-methoxy-α-PVP, 25-I-NBOMe, and meclonazepam) from different drug classes using pooled human S9 fraction (pS9) or pooled human liver microsomes combined with cytosol (pHLM/pHLC) after addition of the co-substrates for the main metabolic phase I and II reactions. Second to compare results to published data generated using primary human hepatocytes and human urine samples. Results of the incubations with pS9 or pHLM/pHLC were comparable in number and abundance of metabolites. Formation of metabolites, particularly after multi-step reactions needed a longer incubation time. However, incubations using human liver preparations resulted in a lower number of total detected metabolites compared to PHH, but they were still able to allow the identification of the main human urinary excretion products. Human liver preparations and particularly the pooled S9 fraction could be shown to be a sufficient and more cost-efficient alternative in context of metabolism studies also for developing toxicological urine screenings. It might be recommended to use the

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.

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....... The results derived from this study clearly demonstrated a 31.3% increase in methane production yield in the CSTR reactor, at steady-state, after bioaugmentation. It indicated that this new solution to counteract ammonia inhibition was more practical and effective compared with other methods applied today...

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...

PENGARUH Ph, KADAR XILOSA DAN KADAR GLUKOSA TERHADAP PRODUKSI XYLITOL OLEH Candida shehatae WAY 08 [The Influence of Intial Xylose and Glucose Consentration on Xylitol production by Candida shehatae WAY 08

Directory of Open Access Journals (Sweden)

Wisnu Adi Yulianto 1

2001-08-01

Full Text Available The objectiviea of this research were to determine the optimum culture conditions of initial pH, xylose and glucose concentration for xylitol production by Candida shehatae WAY 08. The initial pH was altered whitin the range of 4-7, the xylose concentration from 5020%, and the glucose (cosubstrate from 0-4%. The fermentation was performed at 30°C in 500 ml erlenmeyer flaks placed in a shaker incubator at 250 rpm for 7d. biomas concentration war determined by oven method. Xylose, glucose and xylitol concentrations were determined by HPCL.the result incated that the highest xylitol volumetric productivity of Candida shehatae WAY 08 was 0,314 g/I/h at the initial pH of 5 in medium containing 150 g/I xylose. Addition of glucose into media inhibited the xylitol production, but in creased the xylitol yield.

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

DEFF Research Database (Denmark)

Dahl, Allan Carsten; Madsen, Jørgen Øgaard

1998-01-01

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......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......-hydroxybutanoate was afforded in >99% ee. Both enantiomers of ethyl 3-hydroxypentanoate, D-(R) in 96% ee and L-(S) in 93% ee, and of ethyl 4-chloro-3-hydroxybutanoate, D-(S) in 98% ee and L-(R) in 94% ee, were obtained. The results demonstrate that the stereoselectivity of baker's yeast can be controlled...

Exploring NAD+ metabolism in host-pathogen interactions.

Science.gov (United States)

Mesquita, Inês; Varela, Patrícia; Belinha, Ana; Gaifem, Joana; Laforge, Mireille; Vergnes, Baptiste; Estaquier, Jérôme; Silvestre, Ricardo

2016-03-01

Nicotinamide adenine dinucleotide (NAD(+)) is a vital molecule found in all living cells. NAD(+) intracellular levels are dictated by its synthesis, using the de novo and/or salvage pathway, and through its catabolic use as co-enzyme or co-substrate. The regulation of NAD(+) metabolism has proven to be an adequate drug target for several diseases, including cancer, neurodegenerative or inflammatory diseases. Increasing interest has been given to NAD(+) metabolism during innate and adaptive immune responses suggesting that its modulation could also be relevant during host-pathogen interactions. While the maintenance of NAD(+) homeostatic levels assures an adequate environment for host cell survival and proliferation, fluctuations in NAD(+) or biosynthetic precursors bioavailability have been described during host-pathogen interactions, which will interfere with pathogen persistence or clearance. Here, we review the double-edged sword of NAD(+) metabolism during host-pathogen interactions emphasizing its potential for treatment of infectious diseases.

Thermophilic anaerobic co-digestion of poultry litter and thin stillage.

Science.gov (United States)

Sharma, Deepak; Espinosa-Solares, Teodoro; Huber, David H

2013-05-01

The purpose of this study was to test whether the performance of a thermophilic CSTR digester that has been stabilized on poultry litter will be enhanced or diminished by the addition of thin stillage as co-substrate. Replicate laboratory digesters, derived from a stable pilot-scale digester, were operated with increasing ratios (w/w) of thin stillage/poultry litter feedstock. After a period of adaptation to 20% and 40% thin stillage, digester performance showed increases in biogas, percent methane and COD removal, as well as a decrease in volatile acids. Peak performance occurred with 60% thin stillage. However, 80% thin stillage caused significant reduction of performance, including declines of methanogenic activity and COD removal. In conclusion, supplementing the thermophilic digestion of poultry litter with thin stillage improved the bioenergy (methane) output, but thin stillage became inhibitory at high concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

Mesophilic co-digestion of dairy manure and lipid rich solid slaughterhouse wastes: process efficiency, limitations and floating granules formation.

Science.gov (United States)

Pitk, Peep; Palatsi, Jordi; Kaparaju, Prasad; Fernández, Belén; Vilu, Raivo

2014-08-01

Lipid and protein rich solid slaughterhouse wastes are attractive co-substrates to increase volumetric biogas production in co-digestion with dairy manure. Addition of decanter sludge (DS), containing 42.2% of lipids and 35.8% of proteins (total solids basis), up to 5% of feed mixture resulted in a stable process without any indication of long chain fatty acids (LCFA) or free ammonia (NH3) inhibition and in 3.5-fold increase of volumetric biogas production. Contrary, only lipids addition as technical fat (TF) at over 2% of feed mixture resulted in formation of floating granules (FG) and process efficiency decrease. Formed FG had low biodegradability and its organic part was composed of lipids and calcium salts of LCFAs. Anaerobic digestion process intentionally directed to FG formation, could be a viable option for mitigation and control of lipids overload and derived LCFA inhibition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Novel enzymic hydrolytic dehalogenation of a chlorinated aromatic

International Nuclear Information System (INIS)

Scholten, J.D.; Chang, Kaihsuan; Dunaway-Mariano, D.; Babbitt, P.C.; Charest, H.; Sylvestre, M.

1991-01-01

Microbial enzyme systems may be used in the biodegradation of persistent environmental pollutants. The three polypeptide components of one such system, the 4-chlorobenzoate dehalogenase system, have been isolated, and the chemical steps of the 4-hydroxybenzoate-forming reaction that they catalyze have been identified. The genes contained within a 4.5-filobase Pseudomonas sp. strain CBS3 chromosomal DNA fragment that encode dehalogenase activity were selectively expressed in transformed Escherichia coli. Oligonucleotide sequencing revealed a stretch of homology between the 57-kilodalton (kD) polypeptide and several magnesium adenosine triphosphate (MgATP)-cleaving enzymes that allowed MgATP and coenzyme A (CoA) to be identified as the dehalogenase cosubstrate and cofactor, respectively. The dehalogenase activity arises from two components, a 4-chlorobenzoate:CoA ligase-dehalogenase (an αβ dimer of the 57- and 30-kD polypeptides) and a thioesterase (the 16-kD polypeptide)

Anaerobic co-digestion of swine manure and crude glycerol derived from animal fat - Effect of hydraulic retention time

DEFF Research Database (Denmark)

Lymperatou, Anna; Skiadas, Ioannis V.; Gavala, Hariklia N.

2018-01-01

Crude glycerol (CG), an abundant by-product of bio-diesel production, has been identified as a suitable co-substrate for improving the biogas production of livestock manure through anaerobic digestion (AD). In this study, the potential of utilizing CG generated from the esterification of animal......, biochemical methane potential tests indicated that the addition of 1% w/w CG to swine manure-AD is more efficient in terms of percent of theoretical amount of methane obtained than the addition of 3% w/w. However, in continuous experiments, co-digestion of manure with 3% w/w CG did not exhibit any sign...... fats for biogas production was studied in both batch and continuous AD experiments, with emphasis on the importance of the hydraulic retention time (HRT). Batch experiments showed that the limiting step in the methane production rate during CG mono-digestion was the 1,3-propanediol uptake. Additionally...

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.)

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.)

Co-fermentation of sewage sludge with ryegrass for enhancing hydrogen production: Performance evaluation and kinetic analysis.

Science.gov (United States)

Yang, Guang; Wang, Jianlong

2017-11-01

The low C/N ratio and low carbohydrate content of sewage sludge limit its application for fermentative hydrogen production. In this study, perennial ryegrass was added as the co-substrate into sludge hydrogen fermentation with different mixing ratios for enhancing hydrogen production. The results showed that the highest hydrogen yield of 60mL/g-volatile solids (VS) added was achieved when sludge/perennial ryegrass ratio was 30:70, which was 5 times higher than that from sole sludge. The highest VS removal of 21.8% was also achieved when sludge/perennial ryegrass ratio was 30:70, whereas VS removal from sole sludge was only 0.7%. Meanwhile, the co-fermentation system simultaneously improved hydrogen production efficiency and organics utilization of ryegrass. Kinetic analysis showed that the Cone model fitted hydrogen evolution better than the modified Gompertz model. Furthermore, hydrogen yield and VS removal increased with the increase of dehydrogenase activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

NAD+ and SIRT3 control microtubule dynamics and reduce susceptibility to antimicrotubule agents

Science.gov (United States)

Harkcom, William T.; Ghosh, Ananda K.; Sung, Matthew S.; Matov, Alexandre; Brown, Kevin D.; Giannakakou, Paraskevi; Jaffrey, Samie R.

2014-01-01

Nicotinamide adenine dinucleotide (NAD+) is an endogenous enzyme cofactor and cosubstrate that has effects on diverse cellular and physiologic processes, including reactive oxygen species generation, mitochondrial function, apoptosis, and axonal degeneration. A major goal is to identify the NAD+-regulated cellular pathways that may mediate these effects. Here we show that the dynamic assembly and disassembly of microtubules is markedly altered by NAD+. Furthermore, we show that the disassembly of microtubule polymers elicited by microtubule depolymerizing agents is blocked by increasing intracellular NAD+ levels. We find that these effects of NAD+ are mediated by the activation of the mitochondrial sirtuin sirtuin-3 (SIRT3). Overexpression of SIRT3 prevents microtubule disassembly and apoptosis elicited by antimicrotubule agents and knockdown of SIRT3 prevents the protective effects of NAD+ on microtubule polymers. Taken together, these data demonstrate that NAD+ and SIRT3 regulate microtubule polymerization and the efficacy of antimicrotubule agents. PMID:24889606

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.

Microbial production of biovanillin.

Science.gov (United States)

Converti, A; Aliakbarian, B; Domínguez, J M; Bustos Vázquez, G; Perego, P

2010-07-01

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.

Evaluating the effects of activated carbon on methane generation and the fate of antibiotic resistant genes and class I integrons during anaerobic digestion of solid organic wastes.

Science.gov (United States)

Zhang, Jingxin; Mao, Feijian; Loh, Kai-Chee; Gin, Karina Yew-Hoong; Dai, Yanjun; Tong, Yen Wah

2018-02-01

The effects of activated carbon (AC) on methane production and the fate of antibiotic resistance genes (ARGs) were evaluated through comparing the anaerobic digestion performance and transformation of ARGs among anaerobic mono-digestion of food waste, co-digestion of food waste and chicken manure, and co-digestion of food waste and waste activated sludge. Results showed that adding AC in anaerobic digesters improved methane yield by at least double through the enrichment of bacteria and archaea. Conventional digestion process showed ability in removing certain types of ARGs, such as tetA, tetX, sul1, sul2, cmlA, floR, and intl1. Supplementing AC in anaerobic digester enhanced the removal of most of the ARGs in mono-digestion of food waste. The effects tended to be minimal in co-digestion of co-substrates such as chicken manure and waste activated sludge, both of which contain a certain amount of antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Hydrolytic activities of extracellular enzymes in thermophilic and mesophilic anaerobic sequencing-batch reactors treating organic fractions of municipal solid wastes.

Science.gov (United States)

Kim, Hyun-Woo; Nam, Joo-Youn; Kang, Seok-Tae; Kim, Dong-Hoon; Jung, Kyung-Won; Shin, Hang-Sik

2012-04-01

Extracellular enzymes offer active catalysis for hydrolysis of organic solid wastes in anaerobic digestion. To evidence the quantitative significance of hydrolytic enzyme activities for major waste components, track studies of thermophilic and mesophilic anaerobic sequencing-batch reactors (TASBR and MASBR) were conducted using a co-substrate of real organic wastes. During 1day batch cycle, TASBR showed higher amylase activity for carbohydrate (46%), protease activity for proteins (270%), and lipase activity for lipids (19%) than MASBR. In particular, the track study of protease identified that thermophilic anaerobes degraded protein polymers much more rapidly. Results revealed that differences in enzyme activities eventually affected acidogenic and methanogenic performances. It was demonstrated that the superior nature of enzymatic capability at thermophilic condition led to successive high-rate acidogenesis and 32% higher CH(4) recovery. Consequently, these results evidence that the coupling thermophilic digestion with sequencing-batch operation is a viable option to promote enzymatic hydrolysis of organic particulates. Copyright © 2012 Elsevier Ltd. All rights reserved.

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. © 2016 Authors; published by Portland Press Limited.

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

are dependent on sulphur deriving from cysteine. The effect of cysteine on the syntheses was investigated at non-toxic and toxic concentrations of the hepatotoxic drug acetaminophen (AA). Administration of AA trapped radioactivity (35S) in the pre-labelled PAPS and GSH pools by formation of the metabolites, AA......-sulphate and AA-GSH. Turnover rates were determined from the decline of AA-sulphate and AA-GSH specific activity. Syntheses of PAPS and GSH were calculated by multiplying the rates with the concentrations of the respective co-substrates. Increasing AA concentration from non-toxic to toxic levels resulted.......05) in experiments with non-toxic AA concentrations. In experiments with toxic AA concentrations opposite effects of cysteine were seen, i.e. median PAPS synthesis was reduced (3 to 2 nmol/10(6) cells/min) (P less than 0.05) while median GSH synthesis was unchanged (23 to 16 nmol/10(6) cells/min). The present method...

Cardboard proportions and total solids contents as driving factors in dry co-fermentation of food waste.

Science.gov (United States)

Capson-Tojo, Gabriel; Trably, Eric; Rouez, Maxime; Crest, Marion; Bernet, Nicolas; Steyer, Jean-Philippe; Delgenès, Jean-Philippe; Escudié, Renaud

2018-01-01

This study evaluated the influence of the co-substrate proportions (0-60% of cardboard in dry basis) and the initial total solid contents (20-40%) on the batch fermentation performance. Maximum hydrogen yields were obtained when mono-fermenting food waste at high solids contents (89mlH 2 ·gVS -1 ). The hydrogen yields were lower when increasing the proportions of cardboard. The lower hydrogen yields at higher proportions of cardboard were translated into higher yields of caproic acid (up to 70.1gCOD·kgCOD bio -1 ), produced by consumption of acetic acid and hydrogen. The highest substrate conversions were achieved at low proportions of cardboard, indicating a stabilization effect due to higher buffering capacities in co-fermentation. Clostridiales were predominant in all operational conditions. This study opens up new possibilities for using the cardboard proportions for controlling the production of high added-value products in dry co-fermentation of food waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Storage of catch crops to produce biogas

DEFF Research Database (Denmark)

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

2014-01-01

. On the contrary, the poor quality of IR silage, due to its high TS content, made it inappropriate as feedstock for biogas production. A TS content of 25-35% is preferable, to obtain a proper fermentation avoid leachate run-off and growth of Clostridium sp. or mold formation. Avoiding soil particles in the bales......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...... crop in July-August to the end of the growing season and harvest in late October. Hence, for use of the biomass in biogas production there is a need for storage of the biomass. Storage as silage would guarantee the availability of the feedstock for biogas production during the whole year. A proper...

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

Kinetic parameter estimation model for anaerobic co-digestion of waste activated sludge and microalgae.

Science.gov (United States)

Lee, Eunyoung; Cumberbatch, Jewel; Wang, Meng; Zhang, Qiong

2017-03-01

Anaerobic co-digestion has a potential to improve biogas production, but limited kinetic information is available for co-digestion. This study introduced regression-based models to estimate the kinetic parameters for the co-digestion of microalgae and Waste Activated Sludge (WAS). The models were developed using the ratios of co-substrates and the kinetic parameters for the single substrate as indicators. The models were applied to the modified first-order kinetics and Monod model to determine the rate of hydrolysis and methanogenesis for the co-digestion. The results showed that the model using a hyperbola function was better for the estimation of the first-order kinetic coefficients, while the model using inverse tangent function closely estimated the Monod kinetic parameters. The models can be used for estimating kinetic parameters for not only microalgae-WAS co-digestion but also other substrates' co-digestion such as microalgae-swine manure and WAS-aquatic plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Czech Academy of Sciences Publication Activity Database

Fliegerová, Kateřina; Mrázek, Jakub; Kajan, M.; Podmirseg, S.M.; Insam, H.

2012-01-01

Roč. 57, č. 4 (2012), s. 281-284 ISSN 0015-5632 R&D Projects: GA ČR GPP503/10/P394; GA MZe QI92A286 Institutional research plan: CEZ:AV0Z50450515 Keywords : biogas * maize silage * swine manure Subject RIV: DM - Solid Waste and Recycling Impact factor: 0.791, year: 2012

Treatment of spices with ionizing radiation - chemical, organoleptical, microbiological and toxicological analyses. Pt. 2. Behandlung von Gewuerzen mit ionisierenden Strahlen - chemische, sensorische, mikrobiologische und toxikologische Aspekte. T. 2

Energy Technology Data Exchange (ETDEWEB)

Schuettler, C; Boegl, W

1984-09-01

In the present second part of a study of the relevant literature the results of tests on 14 radiation treated spices and 2 radiation treated spice-mixtures were evaluated. The tests in this part contain mainly toxicological but also chemical and sensorial analyses. Most of the spices were treated with gamma radiation from cobalt-60 sources with doses between 80 Gy and 60 kGy. This part contains a cumulated subject index for part 1 and part 2.

Ruthenium(II)-tris-bipyridine and titaniumdioxide - photocatalysts for solar induced water remediation; Ruthenium(II)-tris-bipyridin und Titandioxid - Photokatalysatoren zum solarinduzierten Abbau von Schadstoffen

Energy Technology Data Exchange (ETDEWEB)

Bossmann, S [Lehrstuhl fuer Umweltmesstechnik, Engler-Bunte-Inst., Karlsruhe Univ. (Germany)

1997-01-01

The photophysical and photochemical properties of photocatalysts capable of working under solar-light-irradiation are of great interest. An especially promising application is the development of low-cost `Advanced Oxidation Procedures` (AOP). The aim of this endeavor is the detoxification of hazardous chemicals in wastewaters, which cannot be treated by conventional techniques. The mineralization of the most (highly) toxic chemicals to CO{sub 2}, H{sub 2}O and simple inorganic compounds is favored by thermodynamics, however various difficulties such as kinetic barriers and hindered diffusion exist in systems for heterogeneous photocatalysis. In that respect, Ruthenium(II)-tris-bipyridine ([Ru(bpy){sub 3}]{sup 2+}) and TiO{sub 2} - codoped photocatalysts offer several advantages. The photoreactive centers consist of supramolecular units of [Ru(bpy){sub 3}]{sup 2+} and TiO{sub 2} - nanocrystals. Pollutants, such as our model compound 2,4-Dimethylaniline, diffuse through the framework of zeolite Y and undergo oxidative degradation at the reactive centers of the photocatalysts in the presence of H{sub 2}O{sub 2}. Under the aspect of application, the size of the zeolite Y-particles (diameter: 1x10{sup -6} m in average) permits their easy handling in filtration and recyling operations. (orig.) [Deutsch] Die photophysikalischen und -chemischen Eigenschaften von Katalysatoren, die das Licht der Sonne als kostenguenstige Energiequelle ausnutzen, treten immer staerker in den Vordergrund des Interesses. Dies gilt vor allem fuer ihren Einsatz in `Advanced Oxidation Technologies` (AOT`s) zur Entgiftung toxischer Substanzen im Abwasser. Die Mineralisation der meisten (hoch)giftigen Chemikalien zu CO{sub 2}, H{sub 2}O und einfachen anorganischen Verbindungen ist zwar thermodynamisch beguenstigt, es treten jedoch sowohl kinetische Hemmschwellen als auch Diffusionshindernisse in der heterogenen Photokatalyse auf. Ruthenium(II)-tris-bipyridin ([Ru(bpy){sub 3}]{sup 2+}) und TiO{sub 2} - codotierte Photokatalysatoren besitzen die folgenden Vorteile: Die photoreaktiven Zentren bestehen aus im Zeolithen Y immobilisierten supramolekularen Einheiten aus [Ru(bpy){sub 3}]{sup 2+} und TiO{sub 2} - Nanokristallen. Schadstoffe wie 2,4-Dimethylanilin koennen durch den zeolithischen Wirtskoerper diffundieren und werden an den photoreaktiven Zentren in Gegenwart von H{sub 2}O{sub 2} oxidativ abgebaut. Die Groesse der zeolithischen Wirtskoerper (Durchmesser: 1x10{sup -6} m) erleichtert ihre technische Handhabung wie z.B. Filtration und Recycling. (orig.)

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

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. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Synthesis of cinnamyl alcohol from cinnamaldehyde with Bacillus stearothermophilus alcohol dehydrogenase as the isolated enzyme and in recombinant E. coli cells.

Science.gov (United States)

Pennacchio, Angela; Rossi, Mosè; Raia, Carlo A

2013-07-01

The synthesis of the aroma chemical cinnamyl alcohol (CMO) by means of enzymatic reduction of cinnamaldehyde (CMA) was investigated using NADH-dependent alcohol dehydrogenase from Bacillus stearothermophilus both as an isolated enzyme, and in recombinant Escherichia coli whole cells. The influence of parameters such as reaction time and cofactor, substrate, co-substrate 2-propanol and biocatalyst concentrations on the bioreduction reaction was investigated and an efficient and sustainable one-phase system developed. The reduction of CMA (0.5 g/L, 3.8 mmol/L) by the isolated enzyme occurred in 3 h at 50 °C with 97% conversion, and yielded high purity CMO (≥98%) with a yield of 88% and a productivity of 50 g/genzyme. The reduction of 12.5 g/L (94 mmol/L) CMA by whole cells in 6 h, at 37 °C and no requirement of external cofactor occurred with 97% conversion, 82% yield of 98% pure alcohol and a productivity of 34 mg/gwet cell weight. The results demonstrate the microbial system as a practical and efficient method for larger-scale synthesis of CMO.

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.

Role of NAD+ and mitochondrial sirtuins in cardiac and renal diseases.

Science.gov (United States)

Hershberger, Kathleen A; Martin, Angelical S; Hirschey, Matthew D

2017-04-01

The coenzyme nicotinamide adenine dinucleotide (NAD + ) has key roles in the regulation of redox status and energy metabolism. NAD + depletion is emerging as a major contributor to the pathogenesis of cardiac and renal diseases and NAD + repletion strategies have shown therapeutic potential as a means to restore healthy metabolism and physiological function. The pleotropic roles of NAD + enable several possible avenues by which repletion of this coenzyme could have therapeutic efficacy. In particular, NAD + functions as a co-substrate in deacylation reactions carried out by the sirtuin family of enzymes. These NAD + -dependent deacylases control several aspects of metabolism and a wealth of data suggests that boosting sirtuin activity via NAD + supplementation might be a promising therapy for cardiac and renal pathologies. This Review summarizes the role of NAD + metabolism in the heart and kidney, and highlights the mitochondrial sirtuins as mediators of some of the beneficial effects of NAD + -boosting therapies in preclinical animal models. We surmise that modulating the NAD + -sirtuin axis is a clinically relevant approach to develop new therapies for cardiac and renal diseases.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biocatalytic potential of vanillin aminotransferase from Capsicum chinense

Science.gov (United States)

2014-01-01

Background The conversion of vanillin to vanillylamine is a key step in the biosynthetic route towards capsaicinoids in pungent cultivars of Capsicum sp. The reaction has previously been annotated to be catalysed by PAMT (putative aminotransferase; [GenBank: AAC78480.1, Swiss-Prot: O82521]), however, the enzyme has previously not been biochemically characterised in vitro. Results The biochemical activity of the transaminase was confirmed by direct measurement of the reaction with purified recombinant enzyme. The enzyme accepted pyruvate, and oxaloacetate but not 2-oxoglutarate as co-substrate, which is in accordance with other characterised transaminases from the plant kingdom. The enzyme was also able to convert (S)-1-phenylethylamine into acetophenone with high stereo-selectivity. Additionally, it was shown to be active at a broad pH range. Conclusions We suggest PAMT to be renamed to VAMT (vanillin aminotransferase, abbreviation used in this study) as formation of vanillin from vanillylamine could be demonstrated. Furthermore, due to high stereoselectivity and activity at physiological pH, VAMT is a suitable candidate for biocatalytic transamination in a recombinant whole-cell system. PMID:24712445

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

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.

Biodegradation of Methylene Blue Dye by Sequential Treatment Using Anaerobic Hybrid Reactor and Submerged Aerobic Fixed Film Bioreactor

Science.gov (United States)

Farooqi, Izharul H.; Basheer, Farrukh; Tiwari, Pradeepika

2017-12-01

Laboratory scale experiments were carried out to access the feasibility of sequential anaerobic/aerobic biological treatment for the biodegradation of Methylene Blue (MB) dye. Anaerobic studies were performed using anaerobic hybrid reactor (consisting of UASB and Anaerobic filter) whereas submerged aerobic fixed film reactor was used as aerobic reactor. Degradation of MB dye was attempted using neutralized acetic acid (1000 mg/L) as co-substrate. MB dye concentration was stepwise increased from 10 to 70 mg/L after reaching steady state in each dye concentration. Such a gradual increase in the dye concentration helps in the proper acclimatization of the sludge to dyes thereby avoiding the possible inhibitory effects to biological activities at high dye concentrations. The overall treatment efficiency of MB through sequential anaerobic-aerobic reactor operation was 90% at maximum attempted dye concentration of 70 mg/L. The effluent from anaerobic reactor was analysed for intermediate biodegradation products through HPLC. It was observed that catechol, quinone, amino pyrine, 1,4 diamino benzene were present. However they were absent in final effluent.

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.

Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

Science.gov (United States)

Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

2016-01-01

Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. © 2016 S. Karger AG, Basel.

Feasibility of microbially improved oil recovery (MIOR) in Northern German oil reservoirs; Bakterien zur Erhoehung des Entoelungsgrades in norddeutschen Erdoellagerstaetten

Energy Technology Data Exchange (ETDEWEB)

Amro, M. [Inst. fuer Erdoel- und Erdgasforschung, Clausthal-Zellerfeld (Germany); Kessel, D. [Inst. fuer Erdoel- und Erdgasforschung, Clausthal-Zellerfeld (Germany)

1996-05-01

The scope of this study was to investigate the feasibility of microbially improved oil recovery (MIOR) in Northern German oil reservoirs. Suitable bacterial strains had to be identified. The mechanisms for oil mobilization and incremental recovery had to be investigated. To this end, two independent methods were employed, namely static autoclave tests and dynamic flood experiments. The static tests were carried out without reservoir rock matrix to preselect suitable bacterial strains with a minimum of experimental effort. The selected strains were then tested in dynamic flood experiments under reservoir conditions on Bentheimer sandstone cores to quantify the oil recovery. Key results of the study are: (1) Two bacterial strains were found having excellent metabolic activity with potential for oil recovery under Northern German reservoir conditions. (2) These bacteria can be injected into and transported in the pores of the sandstone. (3) The metabolic activity of these bacteria leads to substantial incremental oil recovery in repeated injection - shut in - production cycles. (4) Incremental oil recovery is attributed to wettability change and biomass production by the metabolites of the bacteria. (orig.) [Deutsch] Das Ziel dieser Arbeit ist die Untersuchung der Anwendbarkeit der mikrobiell verbesserten Erdoelgewinnung in norddeutschen Lagerstaetten. Zunaechst waren hierfuer einsetzbare Bakterienstaemme zu identifizieren. Diese waren dann auf ihr Entoelungsvermoegen zu ueberpruefen. Schliesslich sollten die Entoelungsmechanismen ermittelt werden. Die Vorauswahl potentiell geeigneter Bakterienstaemme erfolgte durch verschiedene mikrobiologische Forschungsinstitute. Zur Minimierung des experimentellen Aufwands wurden diese Staemme dann im Institut fuer Erdoel- und Erdgasforschung in statischen Autoklavenversuchen unter Lagerstaettenbedingungen, jedoch noch ohne Lagerstaettengestein, auf ihre Stoffwechselaktivitaet sowie Art und Eigenschaften ihrer Stoffwechselprodukte

The cold storage economy in Western Europe; Die Kuehlhauswirtschaft in Westeuropa

Energy Technology Data Exchange (ETDEWEB)

Duiven, J E [AEEF, Bruessel (Belgium)

1996-12-31

This article contains a short explanation of the functions of the AEEF, the European Association for Cold Stores and Deep Freeze Rooms. `Cold` is essential for the preparation and preservation of foodstuffs. `Refrigeration` has become a considerable part of our wellbeing. The production and use of cold is dealt with, where the problems of CFC`s are touched on briefly. Some attention is also devoted to the saving of electricity. Some management instruments connected with the quality of services, with safety and with hygiene are also mentioned. All this will be placed in the context of European Guidelines and European Standards, where these refer to this sector, eg: temperature control in the cooling chain, standardisation, safety and protection of the environment (CEN/TC 182), reducing CFC`s, Packing waste, hygiene (HACCP), CO{sub 2} tax etc. Finally, some trends regarding the direction in which the sector will develop follow. (orig.) [Deutsch] Der Vortrag enthaelt eine kurze Darlegung der Funktion der AEEF, des europaeischen Verbandes fuer gewerbliche Kuehl- und Tiefkuehlhaeuser. Fuer das Bereiten und Konservieren von Nahrungsmitteln ist ``Kaelte`` unerlaesslich. ``Kaelte`` ist ein wesentlicher Unterteil unserer Wohlfahrt geworden. Es wird eingegangen auf das Produzieren und das Verwenden von Kaelte, wobei kurz die Problematik der FCKW beruehrt werden wird. Weiter wird auch der Einsparung von Eletrizitaet Aufmerksamkeit gewidmet. Einige mit Qualitaet der Dienstleistung, mit der Sicherheit und mit Hygiene zusammenhaengende Managementsinstrumente werden auch erwaehnt werden. Dies alles wird in den Rahmen von europaeischen Richtlinien und europaeischen Normen gestellt werden insofern diese sich auf diesen Sektor beziehen, z.B. Temperaturkontrolle in der Kuehlkette, Normung, Sicherheit und Umweltschutz (CEN/TC 182), Abbau FCKW, Verpackungsabfall, Hygiene (HACCP), CO2-tax, usw. Zum Schluss folgen dann noch einige Trends hinsichtlich der Richtung in die sich der Sektor

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

The cold storage economy in Western Europe; Die Kuehlhauswirtschaft in Westeuropa

Energy Technology Data Exchange (ETDEWEB)

Duiven, J.E. [AEEF, Bruessel (Belgium)

1995-12-31

This article contains a short explanation of the functions of the AEEF, the European Association for Cold Stores and Deep Freeze Rooms. `Cold` is essential for the preparation and preservation of foodstuffs. `Refrigeration` has become a considerable part of our wellbeing. The production and use of cold is dealt with, where the problems of CFC`s are touched on briefly. Some attention is also devoted to the saving of electricity. Some management instruments connected with the quality of services, with safety and with hygiene are also mentioned. All this will be placed in the context of European Guidelines and European Standards, where these refer to this sector, eg: temperature control in the cooling chain, standardisation, safety and protection of the environment (CEN/TC 182), reducing CFC`s, Packing waste, hygiene (HACCP), CO{sub 2} tax etc. Finally, some trends regarding the direction in which the sector will develop follow. (orig.) [Deutsch] Der Vortrag enthaelt eine kurze Darlegung der Funktion der AEEF, des europaeischen Verbandes fuer gewerbliche Kuehl- und Tiefkuehlhaeuser. Fuer das Bereiten und Konservieren von Nahrungsmitteln ist ``Kaelte`` unerlaesslich. ``Kaelte`` ist ein wesentlicher Unterteil unserer Wohlfahrt geworden. Es wird eingegangen auf das Produzieren und das Verwenden von Kaelte, wobei kurz die Problematik der FCKW beruehrt werden wird. Weiter wird auch der Einsparung von Eletrizitaet Aufmerksamkeit gewidmet. Einige mit Qualitaet der Dienstleistung, mit der Sicherheit und mit Hygiene zusammenhaengende Managementsinstrumente werden auch erwaehnt werden. Dies alles wird in den Rahmen von europaeischen Richtlinien und europaeischen Normen gestellt werden insofern diese sich auf diesen Sektor beziehen, z.B. Temperaturkontrolle in der Kuehlkette, Normung, Sicherheit und Umweltschutz (CEN/TC 182), Abbau FCKW, Verpackungsabfall, Hygiene (HACCP), CO2-tax, usw. Zum Schluss folgen dann noch einige Trends hinsichtlich der Richtung in die sich der Sektor

Biogas production from wheat straw in batch and UASB reactors: the roles of pretreatment and seaweed hydrolysate as a co-substrate.

Science.gov (United States)

Nkemka, Valentine Nkongndem; Murto, Marika

2013-01-01

This research evaluated biogas production in batch and UASB reactors from pilot-scale acid catalysed steam pretreated and enzymatic hydrolysed wheat straw. The results showed that the pretreatment was efficient and, a sugar yield of 95% was obtained. The pretreatment improved the methane yield (0.28 m(3)/kg VS(added)) by 57% compared to untreated straw. Treatment of the straw hydrolysate with nutrient supplementation in a UASB reactor resulted in a high methane production rate, 2.70 m(3)/m(3).d at a sustainable OLR of 10.4 kg COD/m(3).d and with a COD reduction of 94%. Alternatively, co-digestion of the straw and seaweed hydrolysates in a UASB reactor also maintained a stable anaerobic process and can thus reduce the cost of nutrients addition. We have shown that biogas production from wheat straw can be competitive by pretreatment, high methane production rate in UASB reactors and also by co-digestion with seaweed hydrolysate. Copyright © 2012 Elsevier Ltd. All rights reserved.

Biotransformation of Isolan dyes by Aspergillus niger ES-5 under Co-metabolic Conditions for Glucose Oxidase Production

International Nuclear Information System (INIS)

Gomaa, O.M.; Abd El Kareem, H.; Fathey, F.; Montaser, M.; Zaki, Sh.

2008-01-01

Aspergillus niger ES-5 isolated from Egyptian soil was chosen for its high decolorizing performance (90-98.8%) of 4 Isolan dyes (metal reactive azo group). The decolorisation profile was highly dependent on the presence or absence of co-substrates needed for glucose oxidase (GOD) production. The extracellular fluid (ECF), autoclaved mycelia and mycelia grown in dye solution with no supplements showed a sharp drop in decolorisation (0-7.3%) confirming the biological involvement of growth-linked enzymatic system. The metal content of Isolan dyes was analyzed by Energy Dispersive Xray Spectroscopy (EDS), Cr, Cu, Zn and S were found in cultures, and were below the detection limit after 72 hr incubation. A range of 8-50% decrease in decolorisation was obtained when gamma radiation (up to 8 KGy) was used in combination with fungal pellets. A. niger ES-5 showed over 80% decolorisation for a mixture of the 4 dyes, while decolorisation of real textile effluent showed 75%. All previous data suggest a metabolically mediated dye decolorisation mechanism for live A. niger ES- 5 and points to its potential use in dye decolorisation of real textile effluent

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.

How can we improve biomethane production per unit of feedstock in biogas plants?

International Nuclear Information System (INIS)

Asam, Zaki-ul-Zaman; Poulsen, Tjalfe Gorm; Nizami, Abdul-Sattar; Rafique, Rashad; Kiely, Ger; Murphy, Jerry D.

2011-01-01

Biogas production is one of the number of tools that may be used to alleviate the problems of global warming, energy security and waste management. Biogas plants can be difficult to sustain from a financial perspective. The facilities must be financially optimized through use of substrates with high biogas potential, low water content and low retention requirement. This research carried out in laboratory scale batch digesters assessed the biogas potential of energy crops (maize and grass silage) and solid manure fractions from manure separation units. The ultimate methane productivity in terms of volatile solids (VS) was determined as 330, 161, 230, 236, 361 L/kg VS from raw pig slurry, filter pressed manure fiber (FPMF), chemically precipitated manure fiber (CPMF), maize silage and grass silage respectively. Methane productivity based on mass (L/kg substrate) was significantly higher in FPMF (55 L/kg substrate), maize silage (68 L/kg substrate) and grass silage (45-124 L/kg substrate (depending on dry solids of feedstock)) as in comparison to raw pig slurry (10 L/kg substrate). The use of these materials as co-substrates with raw pig slurry will increase significantly the biomethane yield per unit feedstock in the biogas plant.

A Novel Superfamily of Transporters for Allantoin and Other Oxo Derivatives of Nitrogen Heterocyclic Compounds in Arabidopsis

Science.gov (United States)

Desimone, Marcelo; Catoni, Elisabetta; Ludewig, Uwe; Hilpert, Melanie; Schneider, Anja; Kunze, Reinhard; Tegeder, Mechthild; Frommer, Wolf Bernd; Schumacher, Karin

2002-01-01

A wide spectrum of soil heterocyclic nitrogen compounds are potential nutrients for plants. Here, it is shown that Arabidopsis plants are able to use allantoin as sole nitrogen source. By functional complementation of a yeast mutant defective in allantoin uptake, an Arabidopsis transporter, AtUPS1 (Arabidopsis thaliana ureide permease 1), was identified. AtUPS1 belongs to a novel superfamily of plant membrane proteins with five open reading frames in Arabidopsis (identity, 64 to 82%). UPS proteins have 10 putative transmembrane domains with a large cytosolic central domain containing a “Walker A” motif. Transport of 14C-labeled allantoin by AtUPS1 in yeast exhibited saturation kinetics (Km ∼ 52 μM), was dependent on Glc and a proton gradient, and was stimulated by acidic pH. AtUPS1 transports uric acid and xanthine, besides allantoin, but not adenine. Protons are cosubstrates in allantoin transport by AtUPS1, as demonstrated by expression in Xenopus laevis oocytes. In plants, AtUPS1 gene expression was dependent on the nitrogen source. Therefore, AtUPS1 presumably is involved in the uptake of allantoin and other purine degradation products when primary sources are limiting. PMID:11971139

Environmental consequences of future biogas technologies based on separated slurry.

Science.gov (United States)

Hamelin, Lorie; Wesnæs, Marianne; Wenzel, Henrik; Petersen, Bjørn M

2011-07-01

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 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 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 the whole slurry life cycle, including the flows bypassing the biogas plant. This study includes soil carbon balances and a method for quantifying the changes in yield resulting from increased nitrogen availability as well as for quantifying mineral fertilizers displacement. Soil carbon balances showed that between 13 and 50% less carbon ends up in the soil pool with the different biogas alternatives, as opposed to the reference slurry management.

An operando FTIR spectroscopic and kinetic study of carbon monoxide pressure influence on rhodium-catalyzed olefin hydroformylation.

Science.gov (United States)

Kubis, Christoph; Sawall, Mathias; Block, Axel; Neymeyr, Klaus; Ludwig, Ralf; Börner, Armin; Selent, Detlef

2014-09-08

The influence of carbon monoxide concentration on the kinetics of the hydroformylation of 3,3-dimethyl-1-butene with a phosphite-modified rhodium catalyst has been studied for the pressure range p(CO)=0.20-3.83 MPa. Highly resolved time-dependent concentration profiles of the organometallic intermediates were derived from IR spectroscopic data collected in situ for the entire olefin-conversion range. The dynamics of the catalyst and organic components are described by enzyme-type kinetics with competitive and uncompetitive inhibition reactions involving carbon monoxide taken into account. Saturation of the alkyl-rhodium intermediates with carbon monoxide as a cosubstrate occurs between 1.5 and 2 MPa of carbon monoxide pressure, which brings about a convergence of aldehyde regioselectivity. Hydrogenolysis of the acyl intermediate is fast at 30 °C and low pressure of p(CO)=0.2 MPa, but is of minus first order with respect to the solution concentration of carbon monoxide. Resting 18-electron hydrido and acyl complexes that correspond to early and late rate-determining states, respectively, coexist as long as the conversion of the substrate is not complete. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ADPRT inhibitors and hyperthermia as radiosensitizers

International Nuclear Information System (INIS)

Jonsson, G.G.

1985-01-01

Hyperthermia given in combination with gamma radiation has given considerable improvement in the therapeutic results for treatment of malignant tumors. The mechanism behind the hyperthermia effect is probably operative at the tissue level as well as at the molecular level. The metabolism of NAD + in relation to the activity of the chromosomal enzyme ADP-ribosyl transferase (ADPRT) has been studied as a possible molecular mechanism for this effect. The ADPRT activity was measured after radiosensitization with both hyperthermia and nicotinamide, which is a potent inhibitor of ADPRT. The results indicate that hyperthermia can improve the effect of radiotherapy by reducing the supply of NAD + , which is a co-substrate for ADPRT, while nicotinamide functions as a radiosensitizing agent by direct inhibition of the enzyme. The hypothesis is discussed in the thesis where inhibition of ADPRT might increase the radiosensitivity because the radiation-induced DNA damage can not be repaired with normal efficiency. The function of nicotinamide as a radiosensitizer was verified by studies on C3H mice with transplanted spontaneous mammary tumors. Because nicotinamide is not toxic, it seems quite attractive to test this vitamin as a radiosensitizing agent against human tumors. (251 refs.) (author)

Visualization of Nicotine Adenine Dinucleotide Redox Homeostasis with Genetically Encoded Fluorescent Sensors.

Science.gov (United States)

Zhao, Yuzheng; Zhang, Zhuo; Zou, Yejun; Yang, Yi

2018-01-20

Beyond their roles as redox currency in living organisms, pyridine dinucleotides (NAD + /NADH and NADP + /NADPH) are also precursors or cosubstrates of great significance in various physiologic and pathologic processes. Recent Advances: For many years, it was challenging to develop methodologies for monitoring pyridine dinucleotides in situ or in vivo. Recent advances in fluorescent protein-based sensors provide a rapid, sensitive, specific, and real-time readout of pyridine dinucleotide dynamics in single cells or in vivo, thereby opening a new era of pyridine dinucleotide bioimaging. In this article, we summarize the developments in genetically encoded fluorescent sensors for NAD + /NADH and NADP + /NADPH redox states, as well as their applications in life sciences and drug discovery. The strengths and weaknesses of individual sensors are also discussed. These sensors have the advantages of being specific and organelle targetable, enabling real-time monitoring and subcellular-level quantification of targeted molecules in living cells and in vivo. NAD + /NADH and NADP + /NADPH have distinct functions in metabolic and redox regulation, and thus, a comprehensive evaluation of metabolic and redox states must be multiplexed with a combination of various metabolite sensors in a single cell. Antioxid. Redox Signal. 28, 213-229.

A novel type of pathogen defense-related cinnamyl alcohol dehydrogenase.

Science.gov (United States)

Logemann, E; Reinold, S; Somssich, I E; Hahlbrock, K

1997-08-01

We describe an aromatic alcohol dehydrogenase with properties indicating a novel type of function in the defense response of plants to pathogens. To obtain the enzyme free of contamination with possible isoforms, a parsley (Petroselinum crispum) cDNA comprising the entire coding region of the elicitor-responsive gene, ELI3, was expressed in Escherichia coli. In accord with large amino acid sequence similarities with established cinnamyl and benzyl alcohol dehydrogenases from other plants, the enzyme efficiently reduced various cinnamyl and benzyl aldehydes using NADPH as a co-substrate. Highest substrate affinities were observed for cinnamaldehyde, 4-coumaraldehyde and coniferaldehyde, whereas sinapaldehyde, one of the most efficient substrates of several previously analyzed cinnamyl alcohol dehydrogenases and a characteristic precursor molecule of angiosperm lignin, was not converted. A single form of ELI3 mRNA was strongly and rapidly induced in fungal elicitor-treated parsley cells. These results, together with earlier findings that the ELI3 gene is strongly activated both in elicitor-treated parsley cells and at fungal infection sites in parsley leaves, but not in lignifying tissue, suggest a specific role of this enzyme in pathogen defense-related phenylpropanoid metabolism.

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.

Study of lignin biotransformation by Aspergillus fumigatus and white-rot fungi using 14C-labeled and unlabeled kraft lignins

International Nuclear Information System (INIS)

Kadam, K.K.; Drew, S.W.

1986-01-01

The biodegradation of lignin by fungi was studied in shake flasks using 14 C-labeled kraft lignin and in a deep-tank fermentor using unlabeled kraft lignin. Among the fungi screened, A. fumigatus - isolated in our laboratories - was most potent in lignin biotransformation. Dialysis-type fermentation, designed to study possible accumulation of low MW lignin-derived products, showed no such accumulation. Recalcitrant carbohydrates like microcrystalline cellulose supported higher lignolytic activity than easily metabolized carbohydrates like cellobiose. An assay developed to distinguish between CO 2 evolved from lignin and carbohydrate substrates demonstrated no stoichiometric correlation between the metabolism of the two cosubstrates. The submerged fermentations with unlabeled liqnin are difficult to monitor since chemical assays do not give accurate and true results. Lignolytic efficiencies that allowed monitoring of such fermentations were defined. Degraded lignins were clearly superior to C. versicolor in all aspects of lignin degradation; A fumigatus brought about substantial demethoxylation and dehydroxylation, whereas C. versicolor degraded lignins closely resembled undegraded kraft lignin. There was a good agreement among the different indices of lignin degradation, namely, 14 CO evolution, OCH 3 loss, OH loss, and monomer and dimer yield after permanganate oxidation

Gene and process level modulation to overcome the bottlenecks of recombinant proteins expression in Pichia pastoris.

Science.gov (United States)

Prabhu, Ashish A; Boro, Bibari; Bharali, Biju; Chakraborty, Shuchishloka; Dasu, V Venkata

2018-03-28

Process development involving system metabolic engineering and bioprocess engineering has become one of the major thrust for the development of therapeutic proteins or enzymes. Pichia pastoris has emerged as a prominent host for the production of therapeutic protein or enzymes. Despite of producing high protein titers, various cellular and process level bottlenecks hinders the expression of recombinant proteins in P. pastoris. In the present review, we have summarized the recent developments in the expression of foreign proteins in P. pastoris. Further, we have discussed various cellular engineering strategies which include codon optimization, pathway engineering, signal peptide processing, development of protease deficient strain and glyco-engineered strains for the high yield protein secretion of recombinant protein. Bioprocess development of recombinant proteins in large scale bioreactor including medium optimization, optimum feeding strategy and co-substrate feeding in fed batch as well as continuous cultivation have been described. The recent advances in system and synthetic biology studies including metabolic flux analysis in understanding the phenotypic characteristics of recombinant Pichia and genome editing with CRISPR-CAS system have also been summarized. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

The microbial degradation of polycyclic aromatic hydrocarbons in soils and sediments. Der mikrobielle Abbau polyzyklischer aromatischer Kohlenwasserstoffe (PAK) in Boeden und Sedimenten: Mineralisierung, Metabolitenbildung und Entstehung gebundener Rueckstaende

Energy Technology Data Exchange (ETDEWEB)

Mahro, B; Kaestner, M [Technische Univ. Hamburg-Harburg (Germany). Arbeitsbereich Biotechnologie 2

1993-02-01

The microbial degradation of polycylic aromatic hydrocarbons in soils and sediments: mineralization, metabolite excretion and the formation of bound residues microorganisms degrade polycyclic aromatic hydrocarbons (PAH) via three different metabolic pathways: mineralization, cometabolic oxidation or an unspecific triggering of radical reactions. As a result of these microbial transformation processes PAH may be converted to CO[sub 2] and biomass or partially oxidized metabolites. The possible fate of these presumed metabolites in the soil matrix is analyzed. It is pointed out that the formation of humus bound residues, stimulated by microbial exoenzyme activities, may contribute to significant extent to the disappearance of PAHs in soils and sediments. The relevance of this fact for the biological remediation of contaminated soils is discussed. (orig.).

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.)

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

Three-dimensional stability and deformations of opencast slopes; Raeumliche Standfestigkeit und Verformung von Tagebauboeschungen

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Gudehus, G [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Bodenmechanik und Felsbau; Pierschke, K J [Rheinbraun AG, Koeln (Germany)

1996-05-01

Where the inside dump follows the line of face advance the bottom section of the frontal batter of the opencast mine is limited to a so-called face window which is as narrow as possible. Because of the resulting three-dimensional bearing effect the stability is greater and the deformations are less than is the case when excavation proceeds at the same depth over a long stretch. For years the three-dimensional support effect has been determined by means of a calculation model, developed at Rheinbraun, in which, for safety reasons, only the cohesion is assumed. The three-dimensional stability can however be determined ore accurately with a mechanism consisting of several individual elements sliding against each other. A large-scale test has meanwhile proved that this device corresponds to the actual conditions. Deformation calculations are carried out with increasing accuracy by a finite-element-method and on the basis of newly evolved constitutive relation. Cohesive and non-cohesive layers, faults and groundwater horizons are taken into account. For adjustment purposes detailed survey rangings are carried out, and the three-dimensional bearing effect and creep effects are now also allowed for. (orig.) [Deutsch] Die Tagebaurandboeschung wird bei einer dem Abbau folgenden Innenkippe in ihrem untersten Bereich auf ein moeglichst schmales Abbaufenster begrenzt. Durch die damit verbundene raeumliche Tragwirkung ergeben sich eine groessere Standfestigkeit und geringere Verformungen als bei einem ueber eine grosse Laenge gleich tiefen Aushub. Die raeumliche Stuetzwirkung wird in einem bei Rheinbraun entwickelten Rechenmodell bereits seit Jahren erfasst, wobei vorsichtshalber nur die Kohaesion angesetzt wird. Genauer wird die raeumliche Standfestigkeit mit einem Mechanismus aus mehreren gegeneinander gleitenden Teilkoerpern erfasst. Die Realitaetsnaehe wurde durch einen grossmassstaeblichen Versuch inzwischen belegt. Verformungsberechnungen werden mit einer Finite

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

1998-12-31

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

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.)

Effect of static magnetic field on trichloroethylene removal in a biotrickling filter.

Science.gov (United States)

Quan, Yue; Wu, Hao; Yin, Zhenhao; Fang, Yingyu; Yin, Chengri

2017-09-01

A laboratory-scale biotrickling filter combined with a magnetic field (MF-BTF) and a single BTF (S-BTF) were set up to treat trichloroethylene (TCE) gas. The influences of phenol alone and NaAc-phenol as co-substrates and different MF intensities were investigated. At low MF intensity, MF-BTF displayed better performance with 0.20g/L of phenol, 53.6-337.1mg/m 3 of TCE, and empty bed residence times of 202.5s. The performances followed the order MF-BTF (60.0mT)>MF-BTF (30.0mT)>S-BTF (0mT)>MF-BTF (130.0mT), and the removal efficiencies (REs) and maximum elimination capacities (ECs) corresponded to: 92.2%-45.5%, 2656.8mg/m 3 h; 89.8%-37.2%, 2169.1mg/m 3 h; 89.8%-29.8%, 1967.7mg/m 3 h; 76.0%-20.8%, 1697.1mg/m 3 h, respectively. High-throughput sequencing indicated that the bacterial diversity was lower, whereas the relative abundances of Acinetobacter, Chryseobacterium, and Acidovorax were higher in MF-BTF. Results confirmed that a proper MF could improve TCE removal performance in BTF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

International Nuclear Information System (INIS)

Wijetunga, Somasiri; Li Xiufen; Jian Chen

2010-01-01

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 (∼1000 mg/L, ∼2000 mg/L, ∼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.

Metabolism of methanol in acetogenic bacteria

International Nuclear Information System (INIS)

Ivey, D.K.W.

1987-01-01

Acetogens can grown on methanol in the presence of a cosubstrate that is more oxidized than methanol. Three mol of acetate is formed from 4 mol methanol and 2 mol CO 2 . One mol of methanol is oxidized to CO 2 . The levels of the tetrahydrofolate enzymes, carbon monoxide dehydrogenase, and corrinoids indicate the presence of the acetyl CoA pathway when growing on methanol. The acetyl-CoA pathway of acetate synthesis as presently understood does not include methanol as a substrate. It is demonstrated that methanol is oxidized to formaldehyde and then to formate by a methanol dehydrogenase. It is also possible that the methyl group of methanol is transferred directly to either a corrinoid-type enzyme, or tetrahydrofolate. When cells of C. thermoautotrophicum are grown on 14 CO 2 , acetate becomes labeled in both carbons with a ratio 14 CH 3 / 14 COOH of 0.7. In addition, methanol gets labeled. When cells are grown on 14 CH 3 OH, label appears in both acetate carbons with a ratio of 3.3, and also appears in CO 2 . Thus methanol is preferentially incorporated into the methyl group of acetate, whereas CO 2 is the preferred source of the carboxyl carbon

A QM/MM–Based Computational Investigation on the Catalytic Mechanism of Saccharopine Reductase

Directory of Open Access Journals (Sweden)

James W. Gauld

2011-10-01

Full Text Available Saccharopine reductase from Magnaporthe grisea, an NADPH-containing enzyme in the α-aminoadipate pathway, catalyses the formation of saccharopine, a precursor to L-lysine, from the substrates glutamate and α-aminoadipate-δ-semialdehyde. Its catalytic mechanism has been investigated using quantum mechanics/molecular mechanics (QM/MM ONIOM-based approaches. In particular, the overall catalytic pathway has been elucidated and the effects of electron correlation and the anisotropic polar protein environment have been examined via the use of the ONIOM(HF/6-31G(d:AMBER94 and ONIOM(MP2/6-31G(d//HF/6-31G(d:AMBER94 methods within the mechanical embedding formulism and ONIOM(MP2/6-31G(d//HF/6-31G(d:AMBER94 and ONIOM(MP2/6-311G(d,p//HF/6-31G(d:AMBER94 within the electronic embedding formulism. The results of the present study suggest that saccharopine reductase utilises a substrate-assisted catalytic pathway in which acid/base groups within the cosubstrates themselves facilitate the mechanistically required proton transfers. Thus, the enzyme appears to act most likely by binding the three required reactant molecules glutamate, α-aminoadipate-δ-semialdehyde and NADPH in a manner and polar environment conducive to reaction.

Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

International Nuclear Information System (INIS)

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

Improvement on D-xylose to Xylitol Biotransformation by Candida guilliermondii Using Cells Permeabilized with Triton X-100 and Selected Process Conditions.

Science.gov (United States)

Cortez, Daniela Vieira; Mussatto, Solange I; Roberto, Inês Conceição

2016-11-01

Cells of Candida guilliermondii permeabilized with Triton X-100 were able to efficiently produce xylitol from a medium composed only by D-xylose and MgCl 2 ·6H 2 O in potassium phosphate buffer, at 35 °C and pH 6.5. Under these conditions, the results were similar to those obtained when cofactor and co-substrate or nutrients were added to the medium (about 95 % D-xylose was assimilated producing 42 g/L of xylitol, corresponding to 0.80 g/g yield and 2.65 g/L h volumetric productivity). Furthermore, the permeabilized cells kept the D-xylose assimilation in about 90 % and the xylitol production in approx. 40 g/L during three bioconversion cycles of 16 h each. These values are highly relevant when compared to others reported in the literature using enzyme technology and fermentative process, thereby demonstrating the effectiveness of the proposed method. The present study reveals that the use of permeabilized cells is an interesting alternative to obtain high xylitol productivity using low cost medium formulation. This approach may allow the future development of xylitol production from xylose present in lignocellulosic biomass, with additional potential for implementation in biorefinery strategies.

Studies of lysine cyclodeaminase from Streptomyces pristinaespiralis: Insights into the complex transition NAD+ state.

Science.gov (United States)

Ying, Hanxiao; Wang, Jing; Shi, Ting; Zhao, Yilei; Wang, Xin; Ouyang, Pingkai; Chen, Kequan

2018-01-01

Lysine cyclodeaminase (LCD) catalyzes the piperidine ring formation in macrolide-pipecolate natural products metabolic pathways from a lysine substrate through a combination of cyclization and deamination. This enzyme belongs to a unique enzyme class, which uses NAD + as the catalytic prosthetic group instead of as the co-substrate. To understand the molecular details of NAD + functions in lysine cyclodeaminase, we have determined four ternary crystal structure complexes of LCD-NAD + with pipecolic acid (LCD-PA), lysine (LCD-LYS), and an intermediate (LCD-INT) as ligands at 2.26-, 2.00-, 2.17- and 1.80 Å resolutions, respectively. By combining computational studies, a NAD + -mediated "gate keeper" function involving NAD + /NADH and Arg49 that control the binding and entry of the ligand lysine was revealed, confirming the critical roles of NAD + in the substrate access process. Further, in the gate opening form, a substrate delivery tunnel between ε-carboxyl moiety of Glu264 and the α-carboxyl moiety of Asp236 was observed through a comparison of four structure complexes. The LCD structure details including NAD + -mediated "gate keeper" and substrate tunnel may assist in the exploration the NAD + function in this unique enzyme class, and in regulation of macrolide-pipecolate natural product synthesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Lactate has the potential to promote hydrogen sulphide formation in the human colon.

Science.gov (United States)

Marquet, Perrine; Duncan, Sylvia H; Chassard, Christophe; Bernalier-Donadille, Annick; Flint, Harry J

2009-10-01

High concentrations of sulphide are toxic for the gut epithelium and may contribute to bowel disease. Lactate is a favoured cosubstrate for the sulphate-reducing colonic bacterium Desulfovibrio piger, as shown here by the stimulation of sulphide formation by D. piger DSM749 by lactate in the presence of sulphate. Sulphide formation by D. piger was also stimulated in cocultures with the lactate-producing bacterium Bifidobacterium adolescentis L2-32. Other lactate-utilizing bacteria such as the butyrate-producing species Eubacterium hallii and Anaerostipes caccae are, however, expected to be in competition with the sulphate-reducing bacteria (SRB) for the lactate formed in the human colon. Strains of E. hallii and A. caccae produced 65% and 96% less butyrate from lactate, respectively, in a coculture with D. piger DSM749 than in a pure culture. In triculture experiments involving B. adolescentis L2-32, up to 50% inhibition of butyrate formation by E. hallii and A. caccae was observed in the presence of D. piger DSM749. On the other hand, sulphide formation by D. piger was unaffected by E. hallii or A. caccae in these cocultures and tricultures. These experiments strongly suggest that lactate can stimulate sulphide formation by SRB present in the colon, with possible consequences for conditions such as colitis.

Electronic structure of Co islands grown on the {radical}3 x {radical}3-Ag/Ge(111) surface

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiao-Lan; Chou, Chi-Hao; Lin, Chun-Liang; Tomaszewska, Agnieszka; Fu, Tsu-Yi, E-mail: phtifu@phy.ntnu.edu.tw

2011-09-30

By means of room temperature scanning tunneling spectroscopy (RT STS), we have studied the electronic structure of two different Ag/Ge(111) phases as well as Co islands grown on the {radical}3 x {radical}3-Ag/Ge (111) forming either {radical}13 x {radical}13 or 2 x 2 patterns. The spectrum obtained from 4 x 4-Ag/Ge(111) structure shows the existence of a shoulder at 0.7 V which is also present in the electronic structure of the Ge(111)-c2 x 8 and indicates donation of Ge electrons to electronic states of the Ag-driven phase. However, this fact is not supported by the electronic spectrum taken from the {radical}3 x {radical}3-Ag/Ge (111). The complexity of the Co-{radical}13 x {radical}13 islands bonding with the substrate is mirrored by a large number of peaks in their electronic spectra. The spectra obtained from the Co-2 x 2 islands which had grown on the step differ from those taken from Co-2 x 2 islands located along the edge of the terrace by a number of peaks at negative sample bias. This discrepancy is elucidated in terms of dissimilarities of Co-substrate interaction accompanying Co islands growth on different areas of the stepped surface.

Characterization of CobB kinetics and inhibition by nicotinamide.

Directory of Open Access Journals (Sweden)

Julia Gallego-Jara

Full Text Available Lysine acetylation has emerged as a global protein regulation system in all domains of life. Sirtuins, or Sir2-like enzymes, are a family of histone deacetylases characterized by their employing NAD+ as a co-substrate. Sirtuins can deacetylate several acetylated proteins, but a consensus substrate recognition sequence has not yet been established. Product inhibition of many eukaryotic sirtuins by nicotinamide and its analogues has been studied in vitro due to their potential role as anticancer agents. In this work, the kinetics of CobB, the main Escherichia coli deacetylase, have been characterized. To our knowledge, this is the first kinetic characterization of a sirtuin employing a fully acetylated and natively folded protein as a substrate. CobB deacetylated several acetyl-CoA synthetase acetylated lysines with a single kinetic rate. In addition, in vitro nicotinamide inhibition of CobB has been characterized, and the intracellular nicotinamide concentrations have been determined under different growth conditions. The results suggest that nicotinamide can act as a CobB regulator in vivo. A nicotinamidase deletion strain was thus phenotypically characterized, and it behaved similarly to the ΔcobB strain. The results of this work demonstrate the potential regulatory role of the nicotinamide metabolite in vivo.

Characterization of CobB kinetics and inhibition by nicotinamide.

Science.gov (United States)

Gallego-Jara, Julia; Écija Conesa, Ana; de Diego Puente, Teresa; Lozano Terol, Gema; Cánovas Díaz, Manuel

2017-01-01

Lysine acetylation has emerged as a global protein regulation system in all domains of life. Sirtuins, or Sir2-like enzymes, are a family of histone deacetylases characterized by their employing NAD+ as a co-substrate. Sirtuins can deacetylate several acetylated proteins, but a consensus substrate recognition sequence has not yet been established. Product inhibition of many eukaryotic sirtuins by nicotinamide and its analogues has been studied in vitro due to their potential role as anticancer agents. In this work, the kinetics of CobB, the main Escherichia coli deacetylase, have been characterized. To our knowledge, this is the first kinetic characterization of a sirtuin employing a fully acetylated and natively folded protein as a substrate. CobB deacetylated several acetyl-CoA synthetase acetylated lysines with a single kinetic rate. In addition, in vitro nicotinamide inhibition of CobB has been characterized, and the intracellular nicotinamide concentrations have been determined under different growth conditions. The results suggest that nicotinamide can act as a CobB regulator in vivo. A nicotinamidase deletion strain was thus phenotypically characterized, and it behaved similarly to the ΔcobB strain. The results of this work demonstrate the potential regulatory role of the nicotinamide metabolite in vivo.

Bio production of Vanillin from Agro-Industrial Wastes

International Nuclear Information System (INIS)

Abd EI-Aziz, A.B.

2011-01-01

The present study describes an environmentally friendly vanillin production processes from agro industrial wastes. Ferulic 'acid is a well-known product of cereal. brans and sugarcane bagasse lignin degradation, ferulic acid and cellulose degradation sugars were used as feedstock for the vanillin bio production by Debaryomyces hansenii. The bioconversion of ferulic into vanillin by Debaryomyces hansenii was affected by the type and amount of ferulic acid. Addition of purified ferulic acid (2 g/l) and using of adapted yeast cells. increase the yield of vanillin and decrease the secondary products. Yeast extract (3 g/l) and glucose (20 g/l) proved to be the best component as co-substrates for bio production of vanillin. Variable aeration conditions were tested by simultaneously vanilIin the ratio of medium to vessel volume and the agitation speed. under excess aeration, oxidation of a, significant portion of vanillin to vanillic acid occur, thus reducing the vanillin yield. Increasing the inoculum size up to 1 g/I and using low doses of gamma irradiation (0.25 kGy) increase the vanillin production. Under optimum conditions vanillin production from ferulic acid by Debaryomyces attained very high level of 1531 mg/1 with a molar yield of 76.5%

Composting of sewage sludge with solid fraction of digested pulp from agricultural biogas plant

Science.gov (United States)

Czekała, Wojciech; Dach, Jacek; Przybył, Jacek; Mazurwiekiwcz, Jakub; Janczak, Damian; Lewicki, Andrzej; Smurzyńska, Anna; Kozłowski, Kamil

2018-02-01

Sewage sludge management is an important element of environmental protection. Composting and anaerobic digestion are the biological conversion methods for sewage sludge management. Mass and volume reduction is a result of a properly composted process. Solid fraction of digested pulp can be use as co-substrate, because it is good structural material. The aim of the study was to determine the possibility of composting sewage sludge with a solid fraction of digestate. The compost mix consisted of 25 kilograms of sewage sludge and 20 kilograms solid fraction of digestate in fresh mass. The experiment was carried out in laboratory conditions. Bioreactors of 165 dm3 volume were used. The experiment included two stages. Stage I took place in bioreactors and lasted until the cooling phase of the compost was complete. Stage II included compost maturation for a period of eight months (to 287 day of composting). The reduction of mass obtained at the end of Stage I amounted 30.2%. At the end of Stage II, it was 86.7% relative to the initial weight of the compost. The maximum value of temperature was 75.1°C. Studies have shown that sludge with a solid fraction of digestate can be a suitable substrate for composting with sewage sludge.

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.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

Anaerobic treatment of olive mill wastewater and piggery effluents fermented with Candida tropicalis

International Nuclear Information System (INIS)

Martinez-Garcia, Gregorio; Johnson, Anbu Clemensis; Bachmann, Robert T.; Williams, Ceri J.; Burgoyne, Andrea; Edyvean, Robert G.J.

2009-01-01

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 -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%.

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%.

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

2018-01-01

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.

Potential of Penicillium Species in the Bioremediation Field

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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.

Structure-activity relationships and molecular docking of thirteen synthesized flavonoids as horseradish peroxidase inhibitors.

Science.gov (United States)

Mahfoudi, Reguia; Djeridane, Amar; Benarous, Khedidja; Gaydou, Emile M; Yousfi, Mohamed

2017-10-01

For the first time, the structure-activity relationships of thirteen synthesized flavonoids have been investigated by evaluating their ability to modulate horseradish peroxidase (HRP) catalytic activity. Indeed, a modified spectrophotometrically method was carried out and optimized using 4-methylcatechol (4-MC) as peroxidase co-substrate. The results show that these flavonoids exhibit a great capacity to inhibit peroxidase with Ki values ranged from 0.14±0.01 to 65±0.04mM. Molecular docking has been achieved using Auto Dock Vina program to discuss the nature of interactions and the mechanism of inhibition. According to the docking results, all the flavonoids have shown great binding affinity to peroxidase. These molecular modeling studies suggested that pyran-4-one cycle acts as an inhibition key for peroxidase. Therefore, potent peroxidase inhibitors are flavonoids with these structural requirements: the presence of the hydroxyl (OH) group in 7, 5 and 4' positions and the absence of the methoxy (O-CH 3 ) group. Apigenin contributed better in HRP inhibitory activity. The present study has shown that the studied flavonoids could be promising HRP inhibitors, which can help in developing new molecules to control thyroid diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterisation of chlorophyll oxidation mediated by peroxidative activity in olives (Olea europaea L.) cv. Hojiblanca.

Science.gov (United States)

Vergara-Domínguez, Honorio; Roca, María; Gandul-Rojas, Beatriz

2013-08-15

The oxidation of chlorophyll a (chl a) catalysed by peroxidase (POD) from mesocarp of the olive fruit (Olea europaea L., cv Hojiblanca) in the presence of H2O2 and 2,4-dichlorophenol (2,4-DCP), is characterised via the individualised quantification of the products of the enzymatic reaction using a new methodology of HPLC-UV spectrometry. This innovation has allowed the discovery that, in addition to 13(2) OH chl a and 15(1) OH lactone chl a, which are the first products of POD on chl a, the reaction process sequentially creates another series of oxidised chlorophyll derivatives which have not been previously described. Their origins have been linked to POD activity in the presence of 2,4-DCP. Likewise, a study of the effect of the concentration of the various cosubstrates on the POD reaction rate demonstrated that the correct establishment of the relative concentrations of the same ([H2O2]/[2,4-DCP]/[Chl]=1:3:0.02) is crucial to explaining inhibition effects by substrates and carrying out optimum measurements. Therefore, new essential parameters for the determination of POD activity on a chlorophyll substrate are established. Copyright © 2013 Elsevier Ltd. All rights reserved.

Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins.

Science.gov (United States)

Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

2014-07-11

The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. In this study, a draft genome sequence of D. biacutus was established. Sequencing, assembly and annotation resulted in 159 contigs with 5,242,029 base pairs and 4773 predicted genes; 4708 were predicted protein-encoding genes, and 3520 of these had a functional prediction. Proteins and genes were identified that are specifically induced during growth with acetone. A thiamine diphosphate-requiring enzyme appeared to be highly induced during growth with acetone and is probably involved in the activation reaction. Moreover, a coenzyme B12- dependent enzyme and proteins that are involved in redox reactions were also induced during growth with acetone. We present for the first time the genome of a sulfate reducer that is able to grow with acetone. The genome information of this organism represents an important tool for the elucidation of a novel reaction mechanism that is employed by a sulfate reducer in acetone activation.

Batch anaerobic co-digestion of Kimchi factory waste silage and swine manure under mesophilic conditions.

Science.gov (United States)

Kafle, Gopi Krishna; Kim, Sang Hun; Sung, Kyung Ill

2012-11-01

The objective of this study was to investigate the feasibility of anaerobic co-digestion of Kimchi factory waste silage (KFWS) with swine manure (SM). Chinese cabbage (CC) is the major waste generated by a Kimchi factory and KFWS was prepared by mixing CC and rice bran (RB) (70:30 on a dry matter basis). In Experiment I, the biogas potential of CC and RB were measured and, in Experiment II, the test was conducted with different ratios of KFWS and SM (KFWS: SM=0:100; 33:67; 67:33; 100:0 by% volatile solids (VS) basis). KFWS produced a 27% higher biogas yield and a 59% higher methane yield compared to CC. The specific biogas yields increased by 19, 40 and 57% with KFWS-33%, KFWS-67% and KFWS-100%, respectively compared to SM-100% (394 mL/g VS). Similarly, VS removal increased by 37, 51 and 74% with KFWS-33%, KFWS-67% and KFWS-100%, respectively compared to SM-100%. These results suggested that Kimchi factory waste could be effectively treated by making silage, and the silage could be used as a potential co-substrate to enhance biogas production from SM digesters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of Rumen and Manure Microbiomes and Implications for the Inoculation of Anaerobic Digesters.

Science.gov (United States)

Ozbayram, Emine Gozde; Ince, Orhan; Ince, Bahar; Harms, Hauke; Kleinsteuber, Sabine

2018-02-14

Cattle manure is frequently used as an inoculum for the start-up of agricultural biogas plants or as a co-substrate in the anaerobic digestion of lignocellulosic feedstock. Ruminal microbiota are considered to be effective plant fiber degraders, but the microbes contained in manure do not necessarily reflect the rumen microbiome. The aim of this study was to compare the microbial community composition of cow rumen and manure with respect to plant fiber-digesting microbes. Bacterial and methanogenic communities of rumen and manure samples were examined by 454 amplicon sequencing of bacterial 16S rRNA genes and mcrA genes, respectively. Rumen fluid samples were dominated by Prevotellaceae (29%), whereas Ruminococcaceae was the most abundant family in the manure samples (31%). Fibrobacteraceae (12%) and Bacteroidaceae (13%) were the second most abundant families in rumen fluid and manure, respectively. The high abundances of fiber-degrading bacteria belonging to Prevotellaceae and Fibrobacteraceae might explain the better performance of anaerobic digesters inoculated with rumen fluid. Members of the genus Methanobrevibacter were the predominant methanogens in the rumen fluid, whereas methanogenic communities of the manure samples were dominated by the candidate genus Methanoplasma . Our results suggest that inoculation or bioaugmentation with fiber-digesting rumen microbiota can enhance the anaerobic digestion of lignocellulosic biomass.

Comparison of Rumen and Manure Microbiomes and Implications for the Inoculation of Anaerobic Digesters

Directory of Open Access Journals (Sweden)

Emine Gozde Ozbayram

2018-02-01

Full Text Available Cattle manure is frequently used as an inoculum for the start-up of agricultural biogas plants or as a co-substrate in the anaerobic digestion of lignocellulosic feedstock. Ruminal microbiota are considered to be effective plant fiber degraders, but the microbes contained in manure do not necessarily reflect the rumen microbiome. The aim of this study was to compare the microbial community composition of cow rumen and manure with respect to plant fiber-digesting microbes. Bacterial and methanogenic communities of rumen and manure samples were examined by 454 amplicon sequencing of bacterial 16S rRNA genes and mcrA genes, respectively. Rumen fluid samples were dominated by Prevotellaceae (29%, whereas Ruminococcaceae was the most abundant family in the manure samples (31%. Fibrobacteraceae (12% and Bacteroidaceae (13% were the second most abundant families in rumen fluid and manure, respectively. The high abundances of fiber-degrading bacteria belonging to Prevotellaceae and Fibrobacteraceae might explain the better performance of anaerobic digesters inoculated with rumen fluid. Members of the genus Methanobrevibacter were the predominant methanogens in the rumen fluid, whereas methanogenic communities of the manure samples were dominated by the candidate genus Methanoplasma. Our results suggest that inoculation or bioaugmentation with fiber-digesting rumen microbiota can enhance the anaerobic digestion of lignocellulosic biomass.

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.

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

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

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.; Behrens, S.

2017-01-01

ABSTRACT 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

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)

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

Science.gov (United States)

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

2017-10-01

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

Mechanistic studies on the bovine liver mitochondrial dihydroorotate dehydrogenase using kinetic deuterium isotope effects

International Nuclear Information System (INIS)

Hines, V.; Johnston, M.

1989-01-01

Dihydroorotates deuteriated at both C 5 and C 6 have been prepared and used to probe the mechanism of the bovine liver mitochondrial dihydroorotate dehydrogenase. Primary deuterium isotope effects on k cat are observed with both (6RS)-[5(S)- 2 H]- and (6RS)-[6- 2 H]dihydroorotates (3 and 6, respectively); these effects are maximal at low pH. At pH 6.6, D V = 3.4 for the C 5 -deuteriated dihydroorotate (3), and D V = 2.3 for the C 6 -deuteriated compound (6). The isotope effects approach unity at pH 8.8. Analysis of the pH dependence of the isotope effects on k cat reveals a shift in the rate-determining step of the enzyme mechanism as a function of pH. Dihydroorotate oxidation appears to require general base catalysis; this step is completely rate-determining at low pH and isotopically sensitive. Reduction of the cosubstrate, coenzyme Q 6 , is rate-limiting at high pH and is isotopically insensitive; this step appears to require general acid catalysis. The results of double isotope substitution studies and analysis for substrate isotope exchange with solvent point toward a concerted mechanism for oxidation of dihydroorotate. This finding serves to distinguish further the mammalian dehydrogenase from its parasitic cognate, which catalyzes a stepwise oxidation reaction

Biological regeneration of carrier material for the adsorption of halogen hydrocarbons in plants for cleaning up contaminated groundwater. Final report

International Nuclear Information System (INIS)

Ressel, K.

1993-06-01

Halogen hydrocarbons and above all chlorinated hydrocarbons are widespread harmful substances in soils and in groundwater. When cleaning up groundwater contamination, the contaminants are brought into the gas phase by strip processes. From the gas phase, the contaminants can be adsorbed on different carrier materials, mostly active carbon. One was searching for ways to regenerate this adsorption material. The mixed culture from a sea sediment most suitable for the decomposition of chlorinated hydrocarbons was optimized regarding its decomposition performance and was later used on the technical scale. In the decomposition experiments on the large technical scale, the cultures were lodged on filling bodies which has a much higher amount of gaps. In this case, an optimum supply of the micro-organisms with oxygen and methane is guaranteed, which is used as co-substrate. No intermediate product was found in a gas chromatography examination. The biologically occupied stage is situated between a desorption column and the active carbon filters, and reduces the load of harmful substances which can no longer be brought into the gas phase by stripping out. This has the advantage that it can be integrated in existing plants and can be adapted to any case of contamination by lodging adapted micro-organisms on it. The basis for each application must be separately researched. (orig.) [de

A Structural Basis for the pH-Dependent Xanthophyll Cycle in Arabidopsis thaliana[C][W

Science.gov (United States)

Arnoux, Pascal; Morosinotto, Tomas; Saga, Giorgia; Bassi, Roberto; Pignol, David

2009-01-01

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 β-ionone rings, making VDE an elegant example of the adaptation of an asymmetric enzyme to its symmetric substrate. PMID:19638474

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.

Co-composting of hair waste from the tanning industry with de-inking and municipal wastewater sludges.

Science.gov (United States)

Barrena, Raquel; Pagans, Estel la; Artola, Adriana; Vázquez, Felícitas; Sánchez, Antoni

2007-06-01

Production of waste hair in the leather manufacturing industry is increasing every year due to the adoption of hair-save unhairing techniques, leaving the tanners with the problem of coping with yet another solid by-product. Numerous potential strategies for hair utilisation have been proposed. However, the use of hair waste as agricultural fertiliser is one of its most promising applications due to the high nitrogen content of hair. Agricultural value of hair can be increased by composting. This paper deals with the composting of hair from the unhairing of bovine hide. Results indicated that hair cannot be either composted on its own or co-composted with de-inking sludge, a chemical complementary co-substrate. However, good results were obtained when co-composted with raw sludge from a municipal wastewater treatment plant at hair:raw sludge weight ratios 1:1, 1:2 and, 1:4 in lab scale and pilot plant scale composters. In all cases, a more stable product was achieved at the end of the process. Composting in the pilot plant composter was effectively monitored using Static Respiration Indices determined at process temperature at sampling (SRI(T)) and at 37 degrees C (SRI(37)). Notably, SRI(T) values were more sensitive to changes in the biological activity. In contrast, Respiratory Quotient (RQ) values were not adequate to follow the development of the process.

Biological regeneration of carrier material for the adsorption of halogen hydrocarbons in plants for cleaning up contaminated groundwater. Final report. Biologische Regeneration von Traegermaterial fuer die Adsorption von Halogenkohlenwasserstoffen in Anlagen zur Sanierung kontaminierten Grundwassers. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Ressel, K

1993-06-01

Halogen hydrocarbons and above all chlorinated hydrocarbons are widespread harmful substances in soils and in groundwater. When cleaning up groundwater contamination, the contaminants are brought into the gas phase by strip processes. From the gas phase, the contaminants can be adsorbed on different carrier materials, mostly active carbon. One was searching for ways to regenerate this adsorption material. The mixed culture from a sea sediment most suitable for the decomposition of chlorinated hydrocarbons was optimized regarding its decomposition performance and was later used on the technical scale. In the decomposition experiments on the large technical scale, the cultures were lodged on filling bodies which has a much higher amount of gaps. In this case, an optimum supply of the micro-organisms with oxygen and methane is guaranteed, which is used as co-substrate. No intermediate product was found in a gas chromatography examination. The biologically occupied stage is situated between a desorption column and the active carbon filters, and reduces the load of harmful substances which can no longer be brought into the gas phase by stripping out. This has the advantage that it can be integrated in existing plants and can be adapted to any case of contamination by lodging adapted micro-organisms on it. The basis for each application must be separately researched. (orig.)

Nicotinamidase modulation of NAD+ biosynthesis and nicotinamide levels separately affect reproductive development and cell survival in C. elegans.

Science.gov (United States)

Vrablik, Tracy L; Huang, Li; Lange, Stephanie E; Hanna-Rose, Wendy

2009-11-01

Nicotinamide adenine dinucleotide (NAD(+)) is a central molecule in cellular metabolism and an obligate co-substrate for NAD(+)-consuming enzymes, which regulate key biological processes such as longevity and stress responses. Although NAD(+) biosynthesis has been intensely studied, little analysis has been done in developmental models. We have uncovered novel developmental roles for a nicotinamidase (PNC), the first enzyme in the NAD(+) salvage pathway of invertebrates. Mutations in the Caenorhabditis elegans nicotinamidase PNC-1 cause developmental and functional defects in the reproductive system; the development of the gonad is delayed, four uterine cells die by necrosis and the mutant animals are egg-laying defective. The temporal delay in gonad development results from depletion of the salvage pathway product NAD(+), whereas the uv1 cell necrosis and egg-laying defects result from accumulation of the substrate nicotinamide. Thus, regulation of both substrate and product level is key to the biological activity of PNC-1. We also find that diet probably affects the levels of these metabolites, as it affects phenotypes. Finally, we identified a secreted isoform of PNC-1 and confirmed its extracellular localization and functional activity in vivo. We demonstrate that nicotinamide phosphoribosyltransferase (Nampt), the equivalent enzyme in nicotinamide recycling to NAD(+) in vertebrates, can functionally substitute for PNC-1. As Nampt is also secreted, we postulate an evolutionarily conserved extracellular role for NAD(+) biosynthetic enzymes during development and physiology.

Lytic process studies on anaerobic digestion of organic wastes. Etude des activites lytiques intervenant au cours de la digestion anaerobie des dechets organiques; Rapport final

Energy Technology Data Exchange (ETDEWEB)

Durecu, S.; Thauront, J. (PEC Engineering, 95 - Cergy Pontoise (France). Service de Recherche et Developpement); Festino, C.; Aubart, C.; Reisinger, O. (Nancy-1 Univ., 54 - Vandoeuvre-les-Nancy (France). Lab. d' Ecologie Microbienne)

1990-01-01

To improve anaerobic digestion of pig manure, solubilization of the solid fraction was studied as the rate limiting step in the biomethanation process in an experimental completely mixed digester. The performance of conventional digesters should anaerobic microflora were inefficient in degrading complex biopolymers such as plant fibers. For pectin or cellulose, the use of digestible co-substrates accelerated methanation by increasing the yield of methane and a doubling of the apparent first order solubilization rate constant (Kp = 0.090/d). Lignin should methanation by decreasing methane yield and reducing the rate constant (Kp = 0.035/d). This inhibition was unrelated to volatile fatty acid accumulation. Nine strains of pectinolytic and/or cellulolytic bacteria were isolated. Chitin, a structural constituent of many final species, was effectively solubilized dining anaerobic digestion of pig manure. Seven strains of chitinolytic bacteria were isolated by high chitnese activity. The mycolytic power of fermenting manure processes acting through lytic microflora has been shown to be an effective antagonist of soil borne phytopathogenic fungi, as well as a fertilizer. In greenhouse trails, this compiled fraction demonstrated its ability to control flux unit. Keratin enhanced methane production, and increased H{sub 2}S nearly six-fold. Bacterial strains able to solubilize keratin were also used in autoclawed feather meal to extract the amino acids. (KJD)

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.

Reductive dehalogenation activity of indigenous microorganism in sediments of the Hackensack River, New Jersey.

Science.gov (United States)

Sohn, Seo Yean; Häggblom, Max M

2016-07-01

Organohalogen pollutants are of concern in many river and estuarine environments, such as the New York-New Jersey Harbor estuary and its tributaries. The Hackensack River is contaminated with various metals, hydrocarbons and halogenated organics, including polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins. In order to examine the potential for microbial reductive dechlorination by indigenous microorganisms, sediment samples were collected from five different estuarine locations along the Hackensack River. Hexachlorobenzene (HCB), hexabromobenzene (HBB), and pentachloroaniline (PCA) were selected as model organohalogen pollutants to assess anaerobic dehalogenating potential. Dechlorinating activity of HCB and PCA was observed in sediment microcosms for all sampling sites. HCB was dechlorinated via pentachlorobenzene (PeCB) and trichlorobenzene (TriCB) to dichlorobenzene (DCB). PCA was dechlorinated via tetrachloroaniline (TeCA), trichloroanilines (TriCA), and dichloroanilines (DCA) to monochloroaniline (MCA). No HBB debromination was observed over 12 months of incubation. However, with HCB as a co-substrate slow HBB debromination was observed with production of tetrabromobenzene (TeBB) and tribromobenzene (TriBB). Chloroflexi specific 16S rRNA gene PCR-DGGE followed by sequence analysis detected Dehalococcoides species in sediments of the freshwater location, but not in the estuarine site. Analysis targeting 12 putative reductive dehalogenase (rdh) genes showed that these were enriched concomitant with HCB or PCA dechlorination in freshwater sediment microcosms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of 13C-stable isotope probing to identify RDX-degrading microorganisms in groundwater

International Nuclear Information System (INIS)

Cho, Kun-Ching; Lee, Do Gyun; Roh, HyungKeun; Fuller, Mark E.; Hatzinger, Paul B.; Chu, Kung-Hui

2013-01-01

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. Highlights: •SIP identified sixteen groundwater bacteria capable of using RDX and/or its metabolites as a carbon source. •The RDX degraders in groundwater are phylogenetically diverse and different from known RDX degraders. •Cheese whey induced community shift and altered diversity of the RDX-degrading microorganisms over time. -- RDX-degrading bacteria in contaminated groundwater, identified by SIP with 13 C-labeled RDX, are phylogenetically diverse and different from known RDX degraders

Improved stereoselective bioreduction of t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate by Rhodotorula glutinis through heat treatment.

Science.gov (United States)

Luo, Xi; Wang, Ya-Jun; Zheng, Yu-Guo

2016-11-01

Optically pure t-butyl 6-cyano-(3R, 5R)-dihydroxyhexanoate ((R)-1b) is the key precursor for atorvastatin calcium, the most widely used cholesterol-lowering drug. In this work, a strain ZJB-09224 capable of asymmetrically reducing t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate (1a) to corresponding optically pure (R)-1b was successfully isolated from soil sample, identified belonging to Rhodotorula glutinis based on the morphology, physiological tests, and the 18S rDNA sequence analysis. It was found that heat treatment of cell suspension at 45 °C for 25 Min significantly improved R. glutinis ZJB-09224 stereoselectivity. The asymmetric bioreduction of 1a was most efficient at pH 7.5, 35 °C, 50 mM (15.0 g L -1 ) substrate concentration, 40.0 g DCW L -1 cell loading size, 0.54 M (60.0 g L -1 ) sodium lactate acting as co-substrate. Under these optimal conditions, 0.046 M (R)-1b was produced with de (diastereomeric excess) value of 99.2% after 40 H conversion. Moreover, R. glutinis ZJB-09224 has a broad substrate spectrum, making it a potential tool for some valuable chiral alcohol pharmaceutical intermediates synthesis. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Using Grass Cuttings from Sports Fields for Anaerobic Digestion and Combustion

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Meike Nitsche

2017-03-01

Full Text Available Sports fields provide a recreation space for citizens, but also generate grass biomass, which is cut weekly during the main seasons and therefore could be used in energy generation (combustion or anaerobic digestion. To evaluate the technical suitability of the grass cuttings, silage was produced from four sports fields during one vegetation period and investigated for relevant properties. Potential methane yield was determined with batch tests. Mean methane yield was 291.86 lN·kg−1 VSadded (VS, volatile solid. Neutral detergent fiber concentration was low (44.47% DM, dry matter, yet mineral concentration was high in comparison to grass types cut at a lower frequency. Concentrations of Cl, N, and S, which may lead to unfavorable emissions, fouling, and corrosion during combustion, were too high for an unproblematic combustion process. This was still the case even after applying a mineral-reducing pretreatment, which generates a fiber-rich press cake and a press fluid rich in easy soluble substances. Digestion of the press fluid led to methane yields of 340.10 lN·kg−1 VSadded and the press cake had a higher heating value of 19.61 MJ·kg−1 DM, which is close to that of coniferous wood. It can be concluded that biomass from sports fields could be a suitable co-substrate in bio-energy generation.

High-solids anaerobic co-digestion of sewage sludge and food waste in comparison with mono digestions: stability and performance.

Science.gov (United States)

Dai, Xiaohu; Duan, Nina; Dong, Bin; Dai, Lingling

2013-02-01

System stability and performance of high-solids anaerobic co-digestion of dewatered sludge (DS) and food waste (FW) in comparison with mono digestions were investigated. System stability was improved in co-digestion systems with co-substrate acting as a diluting agent to toxic chemicals like ammonia or Na(+). For high-solids digestion of DS, the addition of FW not only improved system stability but also greatly enhanced volumetric biogas production. For high-solids digestion of FW, the addition of DS could reduce Na(+) concentration and help maintain satisfactory stability during the conversion of FW into biogas. System performances of co-digestion systems were mainly determined by the mixing ratios of DS and FW. Biogas production and volatile solids (VSs) reduction in digestion of the co-mixture of DS and FW increased linearly with higher ratios of FW. A kinetic model, which aimed to forecast the performance of co-digestion and to assist reactor design, was developed from long-term semi-continuous experiments. Maximum VS reduction for DS and FW was estimated to be 44.3% and 90.3%, respectively, and first order constant k was found to be 0.17d(-1) and 0.50 d(-1), respectively. Experimental data of co-digestion were in good conformity to the predictions of the model. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of Sirt1 during the ageing process: relevance to protection of synapses in the brain.

Science.gov (United States)

Godoy, Juan A; Zolezzi, Juan M; Braidy, Nady; Inestrosa, Nibaldo C

2014-12-01

Ageing is a stochastic process associated with a progressive decline in physiological functions which predispose to the pathogenesis of several neurodegenerative diseases. The intrinsic complexity of ageing remains a significant challenge to understand the cause of this natural phenomenon. At the molecular level, ageing is thought to be characterized by the accumulation of chronic oxidative damage to lipids, proteins and nucleic acids caused by free radicals. Increased oxidative stress and misfolded protein formations, combined with impaired compensatory mechanisms, may promote neurodegenerative disorders with age. Nutritional modulation through calorie restriction has been shown to be effective as an anti-ageing factor, promoting longevity and protecting against neurodegenerative pathology in yeast, nematodes and murine models. Calorie restriction increases the intracellular levels of the essential pyridine nucleotide, nicotinamide adenine dinucleotide (NAD(+)), a co-substrate for the sirtuin 1 (Sirt1, silent mating-type information regulator 2 homolog 1) activity and a cofactor for oxidative phosphorylation and ATP synthesis. Promotion of intracellular NAD(+) anabolism is speculated to induce neuroprotective effects against amyloid-β-peptide (Aβ) toxicity in some models for Alzheimer's disease (AD). The NAD(+)-dependent histone deacetylase, Sirt1, has been implicated in the ageing process. Sirt1 serves as a deacetylase for numerous proteins involved in several cellular pathways, including stress response and apoptosis, and plays a protective role in neurodegenerative disorders, such as AD.

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.

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.

Stability of a biogas-producing bacterial, archaeal and fungal community degrading food residues.

Science.gov (United States)

Bengelsdorf, Frank R; Gerischer, Ulrike; Langer, Susanne; Zak, Manuel; Kazda, Marian

2013-04-01

The resident microbiota was analyzed in a mesophilic, continuously operating biogas plant predominantly utilizing food residues, stale bread, and other waste cosubstrates together with pig manure and maize silage. The dominating bacterial, archaeal, and eukaryotic community members were characterized by two different 16S/18S rRNA gene culture-independent approaches. Prokaryotic 16S rRNA gene and eukaryotic 18S rRNA gene clone libraries were constructed and further analyzed by restriction fragment length polymorphism (RFLP), 16S/18S rRNA gene sequencing, and phylogenetic tree reconstruction. The most dominant bacteria belonged to the phyla Bacteriodetes, Chloroflexus, and Firmicutes. On the family level, the bacterial composition confirmed high differences among biogas plants studied so fare. In contrast, the methanogenic archaeal community was similar to that of other studied biogas plants. Furthermore, it was possible to identify fungi at the genus level, namely Saccharomyces and Mucor. Both genera, which are important for microbial degradation of complex compounds, were up to now not found in biogas plants. The results revealed their long-term presence as indicated by denaturating gradient gel electrophoresis (DGGE). The DGGE method confirmed that the main members of the microbial community were constantly present over more than one-year period. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Towards Controlling the Glycoform: A Model Framework Linking Extracellular Metabolites to Antibody Glycosylation

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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.

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.

Bioethanol production involving recombinant C. thermocellum hydrolytic hemicellulase and fermentative microbes.

Science.gov (United States)

Das, Saprativ P; Ravindran, Rajeev; Ahmed, Shadab; Das, Debasish; Goyal, Dinesh; Fontes, Carlos M G A; Goyal, Arun

2012-07-01

The enhancement of the biomass productivity of Escherichia coli cells harbouring the truncated 903 bp gene designated as glycoside hydrolase family 43 (GH43) from Clostridium thermocellum showing hemicellulase activity along with its further use in simultaneous saccharification and fermentation (SSF) process is described. (Phosphoric acid) H(3)PO(4)-acetone treatment and ammonia fibre expansion (AFEX) were the pretreatment strategies employed on the leafy biomass of mango, poplar, neem and asoka among various substrates owing to their high hemicellulose content. GH43 showed optimal activity at a temperature of 50 °C, pH 5.4 with stability over a pH range of 5.0-6.2. A 4-fold escalation in growth of the recombinant E. coli cells was observed when grown using repeated batch strategy in LB medium supplemented with glucose as co-substrate. Candida shehatae utilizing pentose sugars was employed for bioethanol production. AFEX pretreatment proved to be better over acid-acetone technique. The maximum ethanol concentration (1.44 g/L) was achieved for AFEX pretreated mango (1%, w/v) followed by poplar with an ethanol titre (1.32 g/L) in shake flask experiments. A 1.5-fold increase in ethanol titre (2.11 g/L) was achieved with mango (1%, w/v) in a SSF process using a table top 2-L bioreactor with 1 L working volume.

“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.

Natural attenuation at a former gas plant site: isotope analyses; Nachweis von Natural Attenuation mittels Isotopenuntersuchungen an einem ehemaligen Kokereistandort

Energy Technology Data Exchange (ETDEWEB)

Nagel, Aglaia; Strauss, Harald; Achten, Christine [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Geologie und Palaeontologie, Muenster (Germany); Stephan, Manuel [Universitaet Duisburg-Essen, Instrumentelle Analytische Chemie, Essen (Germany)

2011-12-15

Natural attenuation of mono- (BTEX) and polycyclic aromatic hydrocarbons (PAHs) was studied in groundwater at a former gas plant site over a distance of about 500 m. The contamination source was located within a 4-6 m thick succession of interbedded silt and sand (K{sub f} =1,4 .10{sup -7} m/s) at a depth of about 5-6 m below the surface. Groundwater flow times between source and the receiving surface waters were determined on the order of a few hundred years. The main contaminants were found to be benzene and naphthalene with concentrations up to 200,000 and 8,500 {mu}g/l, respectively. Over the past 9 years, concentrations within the contaminant plume have decreased and degradation of benzene was proven by compound specific carbon isotope analyses. In addition, sulphur isotope studies revealed that sulphate reduction has played a significant role. This was supported by ambient sulphate concentrations of 300-1,800 {mu}g/l at the site that are sufficient to sustain a long-term perspective for this process. In agreement with these physico-chemical conditions, no transfer of BTEX or PAHs from the plume into the nearby river has been observed. (orig.) [German] An einem ehemaligen Kokereistandort im Ruhrgebiet wurde das Potenzial von Natural Attenuation (natuerlicher Abbau und Rueckhalt) fuer mono- (BTEX) und polyzyklische aromatische Kohlenwasserstoffe (PAK) im Grundwasser auf einer Fliessstrecke von ca. 500 m untersucht. Das Schadenszentrum befindet sich unter eingeebnetem Bergematerial in ca. 5-6 m Tiefe unter Gelaendeoberkante innerhalb einer ca. 4-6 m maechtigen Schluff-Sand-Wechselfolge (K{sub f} =1,4 .10{sup -7} m/s). Im gesamten Aquifer resultieren Fliesszeiten von wenigen Hundert Jahren vom Schadstoffzentrum bis zur Vorflut. Hauptkontaminanten sind Benzen (bis ca. 200.000 {mu}g/l) und Naphthalen (bis ca. 8.500 {mu}g/l). An der Fahnenspitze liegen seit 9 Jahren schrumpfende Konzentrationen vor, die in Einklang mit einem mittels Kohlenstoffisotopie

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.

Long-term observations on the influence of groundwater level variations on BTEX concentrations in groundwater; Langzeituntersuchungen zum Einfluss von Grundwasserschwankungen auf die BTEX-Konzentration im Grundwasser

Energy Technology Data Exchange (ETDEWEB)

Puettmann, W. [J.W. Goethe-Universitaet Frankfurt a. M., Institut fuer Atmosphaere und Umwelt, AG Umweltanalytik, Frankfurt/Main (Germany); Hettwer, K.; Warrelmann, J. [Universitaet Bremen, Zentrum fuer Umweltforschung und Umwelttechnologie, Bremen (Germany); Gaab, S.

2007-06-15

Ort des Eintrags der Kontamination von 240 {mu}g/l auf 1.300 {mu}g/l im Grundwasser ansteigen liess. Umfangreiche Grundwasseranalysen am Standort belegen einen mikrobiellen Schadstoffabbau unter Zehrung der Elektronenakzeptoren O{sub 2}, NO{sub 3} {sup -}, Fe{sup 3+}, SO{sub 4} {sup 2-} und den Ablauf von Methanogenese. Der Abbau wird durch den Nachweis von Metaboliten bestaetigt. Dies zeigt, dass steigende BTEX-Konzentrationen im Grundwasser nicht die Folge eines eingeschraenkten biologischen Abbaus sind. (orig.)

Hydrodynamic or hydrochemical aspects of anthropogenic and naturally induced bank filtration - examples from Berlin/Brandenburg; Hydrodynamische und hydrochemische Aspekte der anthropogen und natuerlich induzierten Uferfiltration am Beispiel von Berlin/Brandenburg

Energy Technology Data Exchange (ETDEWEB)

Massmann, G.; Pekdeger, A. [Freie Universitaet Berlin (Germany). Institut fuer Geologische Wissenschaften, Arbeitsbereich Hydrogeologie; Duennbier, U. [Berliner Wasserbetriebe, Labor, Berlin (Germany); Heberer, T. [Niedersaechsisches Landesamt fuer Verbraucherschutz und Lebensmittelsicherheit (LAVES), Lebensmittelinstitut Oldenburg (Germany); Richter, D. [DVGW - Technologiezentrum Wasser (TZW), Karlsruhe (Germany); Sueltenfuss, J. [Universitaet Bremen (Germany). Institut fuer Umweltphysik, AG Ozeanographie; Tosaki, Y. [University of Tsukuba (Japan). Sustainable Environmental Studies, Graduate School of Life and Environmental Sciences

2009-09-15

Redoxzonen (horizontale bzw. vertikale Redoxabfolge) unterscheiden. Dabei nimmt die Beschaffenheit bzw. Durchlaessigkeit der Gewaessersohle eine Schluesselfunktion ein. Da das Berliner Oberflaechenwasser einen variablen Anteil geklaerten Abwassers enthaelt, konnten einige abwasserbuertige Substanzen (z. B. pharmazeutische Rueckstaende) im Oberflaechenwasser nachgewiesen werden, die jedoch ueberwiegend vollstaendig oder zumindest teilweise bei der Uferfiltration aus dem Wasser entfernt werden. Die Redoxbedingungen nehmen bezueglich der Elimination einiger organischer Spurenstoffe (z. B. Phenazon, Sulfamethoxazol, Clindamycin) eine wichtige Funktion ein, da ihr Abbau abhaengig vom vorherrschenden Redoxmilieu ist. (orig.)

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.)

Development of an aerobic/anaerobic process for in-situ-rehabilitation of a mostly with mineral oil contaminated location. Final report; Entwicklung eines aeroben/anaeroben Verfahrens zur `In situ-Sanierung` eines vorwiegend mineraloelkontaminierten Altlaststandortes. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Auerbach, C; Winsel, E; Wartenberg, G

1994-12-31

- A location contaminated with mineral oil was tested for the possibility of a bioremediation; - the microbiological tests showed, that there is both an aerobiotic and an optional anaerobic autochthonous pollutants degrading microflora but only the activation of the aerobiotic germs was possible by both suitable nutrients and test conditions; - in degrading tests with a high concentration of pollutants a degradation was possible by addition of different nutrients. Within a week a degradation of about 70% was shown. In areas of lower concentration the possible degradation was smaller. - An in-situ-rehabilitation by a hydraulic supply of the soil microorganisms was not possible because of the anisotropic conditions at the location in a depth of 5-10 m; - an in-situ-rehabilitation with both soil air aspiration and aeration, for the supply of the soil microorganisms too, is even possible at anisotropic soil conditions; - now there is knowledge about both a variable filtration and tubing for an optimal adaptation for the bioremediation to the damage; - apparatus were developped for in-situ-rehabilitation for small and medium locations, useable for biological processes too; - there is a wide utilization of the aeration apparatus is because of the careful environmental use. (orig.) [Deutsch] - Ein Mineraloel-kontaminierter Altlaststandort wurde im Hinblick auf eine moegliche biologische Sanierung untersucht. - Die mikrobiologischen Untersuchungen ergaben, dass eine aerobe und fakultativ anaerobe autochthone schadstoffabbauende Mikroflora vorhanden ist, aber nur der aeroben Keime durch geeignete Naehrstoffe und Versuchsbedingungen aktivierbar waren. - In Abbauuntersuchungen durch Zusatz unterschiedlicher Naehrsalze konnte bei hoher Schadstoffkonzentration schon nach 1 Woche ein Abbau > 70% erreicht werden. In niederen Konzentrationsbereichen war die Schadstoffabbaupotenz wesentlich geringer. - Die anisotropen Verhaeltnisse am Standort in 5-10m Tiefe liessen eine In

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.

Plant amino acid-derived vitamins: biosynthesis and function.

Science.gov (United States)

Miret, Javier A; Munné-Bosch, Sergi

2014-04-01

Vitamins are essential organic compounds for humans, having lost the ability to de novo synthesize them. Hence, they represent dietary requirements, which are covered by plants as the main dietary source of most vitamins (through food or livestock's feed). Most vitamins synthesized by plants present amino acids as precursors (B1, B2, B3, B5, B7, B9 and E) and are therefore linked to plant nitrogen metabolism. Amino acids play different roles in their biosynthesis and metabolism, either incorporated into the backbone of the vitamin or as amino, sulfur or one-carbon group donors. There is a high natural variation in vitamin contents in crops and its exploitation through breeding, metabolic engineering and agronomic practices can enhance their nutritional quality. While the underlying biochemical roles of vitamins as cosubstrates or cofactors are usually common for most eukaryotes, the impact of vitamins B and E in metabolism and physiology can be quite different on plants and animals. Here, we first aim at giving an overview of the biosynthesis of amino acid-derived vitamins in plants, with a particular focus on how this knowledge can be exploited to increase vitamin contents in crops. Second, we will focus on the functions of these vitamins in both plants and animals (and humans in particular), to unravel common and specific roles for vitamins in evolutionary distant organisms, in which these amino acid-derived vitamins play, however, an essential role.

Peroxide-Dependent Analyte Conversion by the Heme Prosthetic Group, the Heme Peptide “Microperoxidase-11” and Cytochrome c on Chitosan Capped Gold Nanoparticles Modified Electrodes

Directory of Open Access Journals (Sweden)

Frieder W. Scheller

2012-05-01

Full Text Available In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds. In order to check whether cyt c has an enzymatic activity in the native state where the protein matrix should suppress the inherent peroxidatic activity of its heme prosthetic group, we applied a biocompatible immobilization matrix and very low concentrations of the co-substrate H2O2. The biocatalysts were entrapped on the surface of a glassy carbon electrode in a biocompatible chitosan layer which contained gold nanoparticles. The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication. The catalytic efficiency of microperoxidase-11 is sufficient for sensors indicating HRP substrates, e.g., p-aminophenol, paracetamol and catechol, but also the hydroxylation of aniline and dehalogenation of 4-fluoroaniline. The lower limit of detection for p-aminophenol is comparable to previously published papers with different enzyme systems. The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.

Saccharomyces cerevisiae Atf1p is an alcohol acetyltransferase and a thioesterase in vitro.

Science.gov (United States)

Nancolas, Bethany; Bull, Ian D; Stenner, Richard; Dufour, Virginie; Curnow, Paul

2017-06-01

The alcohol-O-acyltransferases are bisubstrate enzymes that catalyse the transfer of acyl chains from an acyl-coenzyme A (CoA) donor to an acceptor alcohol. In the industrial yeast Saccharomyces cerevisiae this reaction produces acyl esters that are an important influence on the flavour of fermented beverages and foods. There is also a growing interest in using acyltransferases to produce bulk quantities of acyl esters in engineered microbial cell factories. However, the structure and function of the alcohol-O-acyltransferases remain only partly understood. Here, we recombinantly express, purify and characterize Atf1p, the major alcohol acetyltransferase from S. cerevisiae. We find that Atf1p is promiscuous with regard to the alcohol cosubstrate but that the acyltransfer activity is specific for acetyl-CoA. Additionally, we find that Atf1p is an efficient thioesterase in vitro with specificity towards medium-chain-length acyl-CoAs. Unexpectedly, we also find that mutating the supposed catalytic histidine (H191) within the conserved HXXXDG active site motif only moderately reduces the thioesterase activity of Atf1p. Our results imply a role for Atf1p in CoA homeostasis and suggest that engineering Atf1p to reduce the thioesterase activity could improve product yields of acetate esters from cellular factories. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd.

Photoaffinity labeling of undecaprenyl pyrophosphate synthetase with a farnesyl pyrophosphate analogue

International Nuclear Information System (INIS)

Baba, T.; Muth, J.; Allen, C.M.

1985-01-01

The prenyl transferase undecaprenyl pyrophosphate synthetase was partially purified from the cytosolic fraction of Escherichia coli. Its enzymic products were characterized as a family of cis-polyprenyl phosphates, which ranged in carbon number from C55 to C25. The enzyme is constituted of two subunits of approximately 30,000 molecular weight. A radiolabeled photolabile analogue of t,t-farnesyl pyrophosphate, [ 3 H]2-diazo-3-trifluoropropionyloxy geranyl pyrophosphate, was shown to label Lactobacillus plantarum and E. coli undecaprenyl pyrophosphate synthetase on UV irradiation in the presence of isopentenyl pyrophosphate and divalent cations. The only labeled polypeptide migrated on electrophoresis in a sodium dodecyl sulfate-polyacrylamide gel at a molecular weight of approximately 30,000. No protein was radiolabeled when the natural substrate, t,t-farnesyl pyrophosphate was included in the irradiation mixture. Irradiation in the presence of MgCl 2 without isopentenyl pyrophosphate gave less labeling of the polypeptide. Irradiation with only isopentenyl pyrophosphate gave little labeling of the polypeptide. When the enzyme was irradiated with 3H-photoprobe, [ 14 C]isopentenyl pyrophosphate, and MgCl 2 , the labeled polypeptide gave a ratio of 14 C/ 3 H that indicated the product must also bind to the enzyme on irradiation. These results demonstrate the ability to radiolabel the allylic pyrophosphate binding site and possibly product binding site of undecaprenyl pyrophosphate synthetase by a process which is favored when both cosubstrate and divalent cations are present

Electrochemical characteriztion of the bioanode during simultaneous azo dye decolorization and bioelectricity generation in an air-cathode single chambered microbial fuel cell

International Nuclear Information System (INIS)

Sun Jian; Hu Yongyou; Hou Bin

2011-01-01

To achieve high power output based on simultaneously azo dye decolorization using microbial fuel cell (MFC), the bioanode responses during decolorization of a representative azo dye, Congo red, were investigated in an air-cathode single chambered MFC using representative electrochemical techniques. It has been found that the maximum stable voltage output was delayed due to slowly developed anode potential during Congo red decolorization, indicating that the electrons recovered from co-substrate are preferentially transferred to Congo red rather than the bioanode of the MFC and Congo red decolorization is prior to electricity generation. Addition of Congo red had a negligible effect on the Ohmic resistance (R ohm ) of the bioanode, but the charge-transfer resistance (R c ) and the diffusion resistance (R d ) were significantly influenced. The R c and R d firstly decreased then increased with increase of Congo red concentration, probably due to the fact that the Congo red and its decolorization products can act as electron shuttle for conveniently electrons transfer from bacteria to the anode at low concentration, but result in accelerated consumption of electrons at high concentration. Cyclic voltammetry results suggested that Congo red was a more favorable electron acceptor than the bioanode of the MFC. Congo red decolorization did not result in a noticeable decrease in peak catalytic current until Congo red concentration up to 900 mg l -1 . Long-term decolorization of Congo red resulted in change in catalytic active site of anode biofilm.

Anaerobic co-digestion of the organic fraction of municipal solid waste with FOG waste from a sewage treatment plant: Recovering a wasted methane potential and enhancing the biogas yield

International Nuclear Information System (INIS)

Martin-Gonzalez, L.; Colturato, L.F.; Font, X.; Vicent, T.

2010-01-01

Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSW under mesophilic conditions (37 o C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5 L continuous reactor. Biogas yield increased from 0.38 ± 0.02 L g VS feed -1 to 0.55 ± 0.05 L g VS feed -1 as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW.

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. (c) 2010 Elsevier Ltd. All rights reserved.

Conversion of sewage treatment plants on sludge digestion. Energetic and economic optimization potential

International Nuclear Information System (INIS)

Schmitt, Theo G.; Gretzschel, Oliver

2014-03-01

Investigations within the framework of the state-commissioned project ''Re-evaluation of wastewater purification plants with anaerobic sludge treatment with due consideration to framework conditions in terms of the energy and the wastewater management situation in Rhineland-Palatinate'', abbreviated ''NAwaS'', have shown that due to the rise in energy prices and availability of innovative techniques and methods it can be economically efficient, from a plant capacity of 10,000 inhabitants upwards, to convert sewage treatment plants to sludge digestion. Findings from the NAwaS project show the state of Rhineland-Palatinate to have a large potential for the conversion of sewage treatment plants to sludge digestion. Depending on the rate of price increase as well as interest rates the use of digester gas could permit an increase in electricity output by up to 50% over today's levels. Moreover, converted plants would be able to almost completely cover their own heat demand and in addition permit energy savings totalling an expected 5 kWh/(inhabitant x a). If one incorporates the possibilities offered by the procurement of sludge or suitable co-substrates from outside sources, by retrofitting sewage plants with combined heat and power stations or micro gas turbines as well as by process optimisation in existing digestion plants, this gives a further significant increase in potential production capacity and hence economic efficiency. In some of the sewage plants the above measures for saving energy and boosting energy production will even lead to energy self-sufficiency. [de

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.

Anaerobic co-digestion of Tunisian green macroalgae Ulva rigida with sugar industry wastewater for biogas and methane production enhancement.

Science.gov (United States)

Karray, Raida; Karray, Fatma; Loukil, Slim; Mhiri, Najla; Sayadi, Sami

2017-03-01

Ulva rigida is a green macroalgae, abundantly available in the Mediterranean which offers a promising source for the production of valuable biomaterials, including methane. In this study, anaerobic digestion assays in a batch mode was performed to investigate the effects of various inocula as a mixture of fresh algae, bacteria, fungi and sediment collected from the coast of Sfax, on biogas production from Ulva rigida. The results revealed that the best inoculum to produce biogas and feed an anaerobic reactor is obtained through mixing decomposed macroalgae with anaerobic sludge and water, yielding into 408mL of biogas. The process was then investigated in a sequencing batch reactor (SBR) which led to an overall biogas production of 375mL with 40% of methane. Further co-digestion studies were performed in an anaerobic up-flow bioreactor using sugar wastewater as a co-substrate. A high biogas production yield of 114mL g -1 VS added was obtained with 75% of methane. The co-digestion proposed in this work allowed the recovery of natural methane, providing a promising alternative to conventional anaerobic microbial fermentation using Tunisian green macroalgae. Finally, in order to identify the microbial diversity present in the reactor during anaerobic digestion of Ulva rigida, the prokaryotic diversity was investigated in this bioreactor by the denaturing gradient gel electrophoresis (DGGE) method targeting the 16S rRNA gene. Copyright © 2016 Elsevier Ltd. All rights reserved.

Proceedings of the 1. annual Canadian farm and food biogas conference and exhibition

International Nuclear Information System (INIS)

2009-01-01

This conference provided a forum for researchers, farmers, and electric utility operators to discuss issues related to the growth of Canada's biogas industry. Many farmers are now exploring methods of producing biogas from agricultural wastes using anaerobic digestion technologies. However, regulatory problems continue to stall the growth of the fledgling biogas industry. In addition, many biogas plants face challenges related to ensuring reliable grid connections. European and American perspectives on biogas development were presented at the conference along with issues related to provincial and federal regulations and policies. Technologies and strategies for connecting biogas systems with other power systems were presented. The conference was divided into 11 sessions and 2 plenary sessions: (1) B1 grid connection solutions; (2) B2D energy crops and other plant-based co-substrates; (3) B2E Ontario biogas today; (4) B3D mixed materials; (5) B3E siting, odour and safety; (6) B4D economics and policy issues; (7) B4E genset performance and efficiency panel; (8) B5D case studies of food or farm biogas systems; (9) B5E case studies of farm-based systems; (10) B6D biogas next steps; and (11) B6E biogas in an urban setting. The conference featured 42 presentations, of which 5 have been catalogued separately for inclusion in this database. A set of 12 poster presentations were also presented, as well as several networking forums. tabs., figs

Biogas Production by Co-Digestion of Goat Manure with Three Crop Residues

Science.gov (United States)

Zhang, Tong; Liu, Linlin; Song, Zilin; Ren, Guangxin; Feng, Yongzhong; Han, Xinhui; Yang, Gaihe

2013-01-01

Goat manure (GM) is an excellent raw material for anaerobic digestion because of its high total nitrogen content and fermentation stability. Several comparative assays were conducted on the anaerobic co-digestion of GM with three crop residues (CRs), namely, wheat straw (WS), corn stalks (CS) and rice straw (RS), under different mixing ratios. All digesters were implemented simultaneously under mesophilic temperature at 35±1 °C with a total solid concentration of 8%. Result showed that the combination of GM with CS or RS significantly improved biogas production at all carbon-to-nitrogen (C/N) ratios. GM/CS (30:70), GM/CS (70:30), GM/RS (30:70) and GM/RS (50:50) produced the highest biogas yields from different co-substrates (14840, 16023, 15608 and 15698 mL, respectively) after 55 d of fermentation. Biogas yields of GM/WS 30:70 (C/N 35.61), GM/CS 70:30 (C/N 21.19) and GM/RS 50:50 (C/N 26.23) were 1.62, 2.11 and 1.83 times higher than that of CRs, respectively. These values were determined to be the optimal C/N ratios for co-digestion. However, compared with treatments of GM/CS and GM/RS treatments, biogas generated from GM/WS was only slightly higher than the single digestion of GM or WS. This result was caused by the high total carbon content (35.83%) and lignin content (24.34%) in WS, which inhibited biodegradation. PMID:23825574

Kinetic isotope effect studies of the S-adenosylmethionine synthetase reaction

International Nuclear Information System (INIS)

Markham, G.D.; Parkin, D.W.; Schramm, V.L.

1986-01-01

S-adenosylmethionine (AdoMet) synthetase catalyzes a unique substitution reaction at the 5' carbon of MgATP. Kinetic isotope effect (V/K) measurements have been used to investigate the mechanism of AdoMet synthetase from E. coli. Changes in 3 H/ 14 C ratios when AdoMet is formed from a mixture of either ([5'- 14 C]ATP and [5'- 12 C,1'- 3 H]ATP) or ([5'- 3 H]ATP and [5'- 1 H,1'- 14 C]ATP) were examined. The effects of varying the concentrations of the co-substrate methionine and the monovalent cation activator K + were investigated. Substitution of 14 C for 12 C at the 5' position of ATP yields a primary V/K kinetic isotope effect ( 12 C/ 14 C) of 1.128 +/- 0.004 at low K + and methionine concentrations. The observed isotope effect diminishes slightly to 1.107 +/- 0.003 when both K + and methionine are present at saturating concentrations, suggesting that MgATP has only a low commitment to catalysis from at conditions near Vmax. No secondary V/K 3 H isotope effect from [5'- 3 H]ATP was detected ( 1 H/ 3 H) = 0.997 +/- 0.003. The magnitude of the primary 14 C isotope effect and the small secondary 3 H effect demonstrate that AdoMet synthesis occurs with a S/sub N/ 2 transition state which is symmetric with respect to the sulfur nucleophile and the departing tripolyphosphate group

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.

Antigranulocyte scintigraphy of septic loosening of hip prosthesis: influence of different analyzing methods; Antigranulozytenszintigraphie bei septischer Hueft-Endoprothesen-Lockerung: Einfluss unterschiedlicher Auswertemethoden

Energy Technology Data Exchange (ETDEWEB)

Klett, R.; Steiner, D.; Puille, M.; Khalisi, A.; Bauer, R. [Giessen Univ. (Germany). Klinik fuer Nuklearmedizin; Matter, H.P.; Stuerz, H. [Giessen Univ. (Germany). Orthopaedische Klinik

2001-06-01

visuellen Beurteilung der Spaetaufnahme, einer visuellen sowie einer quantitativen Bewertung des Aktivitaets-Zeit-Verlaufes von Frueh- zu Spaetaufnahme verglichen. Verifiziert wurden die Ergebnisse histologisch beziehungsweise mikrobiologisch. Ergebnisse: Es lagen jeweils 14 infizierte und nichtinfizierte Hueft-Endoprothesen vor. Fuer Sensitivitaet, Spezifitaet, negativen und positiven Vorhersagewert ergaben sich bei der visuellen Auswertung der Spaetaufnahme Werte von 0,86, 0,57, 0,80 und 0,67. Bei der visuellen Beurteilung des Zeitverlaufes ergaben sich Werte von 0,86, 0,79, 0,85 und 0,80 und bei der quantitativen Beurteilung Werte von 1, 0,93, 1 und 0,93. Fuer die Interobserveruebereinstimmung ergaben sich Kappa-Koeffizienten von 0,28 {+-} 0,2 fuer die Beurteilung der Spaetaufnahme, 0,48 {+-} 0,17 fuer die visuelle Beurteilung und 1,0 {+-} 0 fuer die quantitative Beurteilung des Zeitverlaufes. Schlussfolgerung: Es ergab sich bei allen verglichenen Groessen eine deutliche Ueberlegenheit der quantitativen Auswertung gegenueber den visuellen Auswertungen. Somit sollte die Antigranulozytenszintigraphie bei der septischen Hueft-Endoprothesen-Lockerung ausschliesslich mittels quantitativer Auswertung des Aktivitaets-Zeit-Verlaufes im Vergleich zu Knochenmark beurteilt werden. (orig.)

Dynamic mechanistic modeling of the multienzymatic one-pot reduction of dehydrocholic acid to 12-keto ursodeoxycholic acid with competing substrates and cofactors.

Science.gov (United States)

Sun, Boqiao; Hartl, Florian; Castiglione, Kathrin; Weuster-Botz, Dirk

2015-01-01

Ursodeoxycholic acid (UDCA) is a bile acid which is used as pharmaceutical for the treatment of several diseases, such as cholesterol gallstones, primary sclerosing cholangitis or primary biliary cirrhosis. A potential chemoenzymatic synthesis route of UDCA comprises the two-step reduction of dehydrocholic acid to 12-keto-ursodeoxycholic acid (12-keto-UDCA), which can be conducted in a multienzymatic one-pot process using 3α-hydroxysteroid dehydrogenase (3α-HSDH), 7β-hydroxysteroid dehydrogenase (7β-HSDH), and glucose dehydrogenase (GDH) with glucose as cosubstrate for the regeneration of cofactor. Here, we present a dynamic mechanistic model of this one-pot reduction which involves three enzymes, four different bile acids, and two different cofactors, each with different oxidation states. In addition, every enzyme faces two competing substrates, whereas each bile acid and cofactor is formed or converted by two different enzymes. First, the kinetic mechanisms of both HSDH were identified to follow an ordered bi-bi mechanism with EBQ-type uncompetitive substrate inhibition. Rate equations were then derived for this mechanism and for mechanisms describing competing substrates. After the estimation of the model parameters of each enzyme independently by progress curve analyses, the full process model of a simple batch-process was established by coupling rate equations and mass balances. Validation experiments of the one-pot multienzymatic batch process revealed high prediction accuracy of the process model and a model analysis offered important insight to the identification of optimum reaction conditions. © 2015 American Institute of Chemical Engineers.

Characterization of structure and activity of garlic peroxidase (POX(1B)).

Science.gov (United States)

El Ichi, Sarra; Miodek, Anna; Sauriat-Dorizon, Hélène; Mahy, Jean-Pierre; Henry, Céline; Marzouki, Mohamed Nejib; Korri-Youssoufi, Hafsa

2011-01-01

Structural characterization and study of the activity of new POX(1B) protein from garlic which has a high peroxidase activity and can be used as a biosensor for the detection of hydrogen peroxide and phenolic compounds were performed and compared with the findings for other heme peroxidases. The structure-function relationship was investigated by analysis of the spectroscopic properties and correlated to the structure determined by a new generation of high-performance hybrid mass spectrometers. The reactivity of the enzyme was analyzed by studies of the redox activity toward various ligands and the reactivity with various substrates. We demonstrated that, in the case of garlic peroxidase, the heme group is pentacoordinated, and has an histidine as a proximal ligand. POX(1B) exhibited a high affinity for hydrogen peroxide as well as various reducing cosubstrates. In addition, high enzyme specificity was demonstrated. The k(cat) and K(M) values were 411 and 400 mM(-1) s(-1) for 3,3',5,5'-tetramethylbenzidine and 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), respectively. Furthermore, the reduction of nitro compounds in the presence of POX(1B) was demonstrated by iron(II) nitrosoalkane complex assay. In addition, POX(1B) showed a great potential for application for drug metabolism since its ability to react with 1-nitrohexane in the presence of sodium dithionite was demonstrated by the appearance of a characteristic Soret band at 411 nm. The high catalytic efficiency obtained in the case of the new garlic peroxidase (POX(1B)) is suitable for the monitoring of different analytes and biocatalysis.

The potential impact on the biodegradation of organic pollutants from composting technology for soil remediation.

Science.gov (United States)

Ren, Xiaoya; Zeng, Guangming; Tang, Lin; Wang, Jingjing; Wan, Jia; Wang, Jiajia; Deng, Yaocheng; Liu, Yani; Peng, Bo

2018-02-01

Large numbers of organic pollutants (OPs), such as polycyclic aromatic hydrocarbons, pesticides and petroleum, are discharged into soil, posing a huge threat to natural environment. Traditional chemical and physical remediation technologies are either incompetent or expensive, and may cause secondary pollution. The technology of soil composting or use of compost as soil amendment can utilize quantities of active microbes to degrade OPs with the help of available nutrients in the compost matrix. It is highly cost-effective for soil remediation. On the one hand, compost incorporated into contaminated soil is capable of increasing the organic matter content, which improves the soil environment and stimulates the metabolically activity of microbial community. On the other hand, the organic matter in composts would increase the adsorption of OPs and affect their bioavailability, leading to decreased fraction available for microorganism-mediated degradation. Some advanced instrumental analytical approaches developed in recent years may be adopted to expound this process. Therefore, the study on bioavailability of OPs in soil is extremely important for the application of composting technology. This work will discuss the changes of physical and chemical properties of contaminated soils and the bioavailability of OPs by the adsorption of composting matrix. The characteristics of OPs, types and compositions of compost amendments, soil/compost ratio and compost distribution influence the bioavailability of OPs. In addition, the impact of composting factors (composting temperature, co-substrates and exogenous microorganisms) on the removal and bioavailability of OPs is also studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics of NAD-metabolism: everything but constant.

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Opitz, Christiane A; Heiland, Ines

2015-12-01

NAD, as well as its phosphorylated form, NADP, are best known as electron carriers and co-substrates of various redox reactions. As such they participate in approximately one quarter of all reactions listed in the reaction database KEGG. In metabolic pathway analysis, the total amount of NAD is usually assumed to be constant. That means that changes in the redox state might be considered, but concentration changes of the NAD moiety are usually neglected. However, a growing number of NAD-consuming reactions have been identified, showing that this assumption does not hold true in general. NAD-consuming reactions are common characteristics of NAD(+)-dependent signalling pathways and include mono- and poly-ADP-ribosylation of proteins, NAD(+)-dependent deacetylation by sirtuins and the formation of messenger molecules such as cyclic ADP-ribose (cADPR) and nicotinic acid (NA)-ADP (NAADP). NAD-consuming reactions are thus involved in major signalling and gene regulation pathways such as DNA-repair or regulation of enzymes central in metabolism. All known NAD(+)-dependent signalling processes include the release of nicotinamide (Nam). Thus cellular NAD pools need to be constantly replenished, mostly by recycling Nam to NAD(+). This process is, among others, regulated by the circadian clock, causing complex dynamic changes in NAD concentration. As disturbances in NAD homoeostasis are associated with a large number of diseases ranging from cancer to diabetes, it is important to better understand the dynamics of NAD metabolism to develop efficient pharmacological invention strategies to target this pathway. © 2015 Authors; published by Portland Press Limited.

Acetate and butyrate as substrates for hydrogen production through photo-fermentation: Process optimization and combined performance evaluation

Energy Technology Data Exchange (ETDEWEB)

Srikanth, S.; Venkata Mohan, S.; Prathima Devi, M.; Peri, Dinakar; Sarma, P.N. [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Tarnaka, Hyderabad, AP 500 007 (India)

2009-09-15

Organic acids viz., acetate and butyrate were evaluated as primary substrates for the production of biohydrogen (H{sub 2}) through photo-fermentation process using mixed culture at mesophilic temperature (34 C). Experiments were performed by varying parameters like operating pH, presence/absence of initiator substrate (glucose) and vitamin solution, type of nitrogen source (mono sodium salt of glutamic acid and amino glutamic acid) and gas (nitrogen/argon) used to create anaerobic microenvironment. Experimental data showed the feasibility of H{sub 2} production along with substrate degradation utilizing organic acids as metabolic substrate but was found to be dependent on the process parameters evaluated. Maximum specific H{sub 2} production and substrate degradation were observed with acetic acid [3.51 mol/Kg COD{sub R}-day; 1.22 Kg COD{sub R}/m{sup 3}-day (92.96%)] compared to butyric acid [3.33 mol/Kg COD{sub R}-day; 1.19 Kg COD{sub R}/m{sup 3}-day (88%)]. Higher H{sub 2} yield was observed under acidophilic microenvironment in the presence of glucose (co-substrate), mono sodium salt of glutamic acid (nitrogen source) and vitamins. Argon induced microenvironment was observed to be effective compared to nitrogen induced microenvironment. Combined process efficiency viz., H{sub 2} production and substrate degradation was evaluated employing data enveloping analysis (DEA) methodology based on the relative efficiency. Integration of dark fermentation with photo-fermentation appears to be an economically viable route for sustainable biohydrogen production if wastewater is used as substrate. (author)

Regulatory properties of 6-phosphofructokinase and control of glycolysis in boar spermatozoa.

Science.gov (United States)

Kamp, G; Schmidt, H; Stypa, H; Feiden, S; Mahling, C; Wegener, G

2007-01-01

Glycolysis is crucial for sperm functions (motility and fertilization), but how this pathway is regulated in spermatozoa is not clear. This prompted to study the location and the regulatory properties of 6-phosphofructokinase (PFK, EC 2.7.1.11), the most important element for control of glycolytic flux. Unlike some other glycolytic enzymes, PFK showed no tight binding to sperm structures. It could readily be extracted from ejaculated boar spermatozoa by sonication and was then chromatographically purified. At physiological pH, the enzyme was allosterically inhibited by near-physiological concentrations of its co-substrate ATP, which induced co-operativity, i.e. reduced the affinity for the substrate fructose 6-phosphate. Inhibition by ATP was reinforced by citrate and H+. Above pH 8, PFK lost all its regulatory properties and showed maximum activity. However, in the physiological pH range, PFK activity was very sensitive to small changes in effectors. At near-physiological substrate concentrations, PFK activity requires activators (de-inhibitors) of which the combination of AMP and fructose 2,6-bisphosphate (F2,6P2) was most efficient as a result of synergistic effects. The kinetics of PFK suggest AMP, F2,6P2, H+, and citrate as allosteric effectors controlling PFK activity in boar spermatozoa. Using immunogold labeling, PFK was localized in the mid-piece and principal piece of the flagellum as well as in the acrosomal area at the top of the head and in the cytoplasmic droplets released from the mid-piece after ejaculation.

Identification of Key Residues for Enzymatic Carboxylate Reduction

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Holly Stolterfoht

2018-02-01

Full Text Available Carboxylate reductases (CARs, E.C. 1.2.1.30 generate aldehydes from their corresponding carboxylic acid with high selectivity. Little is known about the structure of CARs and their catalytically important amino acid residues. The identification of key residues for carboxylate reduction provides a starting point to gain deeper understanding of enzymatic carboxylate reduction. A multiple sequence alignment of CARs with confirmed activity recently identified in our lab and from the literature revealed a fingerprint of conserved amino acids. We studied the function of conserved residues by multiple sequence alignments and mutational replacements of these residues. In this study, single-site alanine variants of Neurospora crassa CAR were investigated to determine the contribution of conserved residues to the function, expressability or stability of the enzyme. The effect of amino acid replacements was investigated by analyzing enzymatic activity of the variants in vivo and in vitro. Supported by molecular modeling, we interpreted that five of these residues are essential for catalytic activity, or substrate and co-substrate binding. We identified amino acid residues having significant impact on CAR activity. Replacement of His 237, Glu 433, Ser 595, Tyr 844, and Lys 848 by Ala abolish CAR activity, indicating their key role in acid reduction. These results may assist in the functional annotation of CAR coding genes in genomic databases. While some other conserved residues decreased activity or had no significant impact, four residues increased the specific activity of NcCAR variants when replaced by alanine. Finally, we showed that NcCAR wild-type and mutants efficiently reduce aliphatic acids.

Metabolism of cysteine by cyteinesulfinate-independent pathway(s) in rat hepatocytes

International Nuclear Information System (INIS)

Stipanuk, M.H.; De La Rosa, J.; Drake, M.R.

1986-01-01

The metabolism of cysteine (CYS) and that of cysteinesulfinate (CSA) were studied in freshly isolated hepatocytes from fed rats. In incubations of rat hepatocytes with either 1 or 25 mM CSA, over 90% of the 14 CO 2 formed from [1- 14 C]CSA could be accounted for by production of hypotaurine plus taurine. In similar incubations with 1 or 25 mM CYS, only 4% of 14 CO 2 evolution from [1- 14 C]CYS could be accounted for by production of hypotaurine plus taurine. Addition of unlabeled CSA inhibited recovery of label from [1- 14 C]CYS as 14 CO 2 by 33%. Metabolism of CYS and of CSA were affected differently by addition of α-ketoglutarate, a cosubstrate for transamination, or of propargylglycine, an inhibitor of cystathionase activity. These data suggest that a substantial proportion of CYS is catabolized by CSA-independent pathways in the rat hepatocyte. Although addition of α-ketoglutarate to incubations of hepatocytes with CSA resulted in a marked increase in CSA catabolism via the transamination pathway, addition of keto acids to incubation systems had little or no effect on production of any metabolite from CYS. Thus, CYS transamination does not appear to be a major pathway of CYS metabolism in the hepatocyte. Inhibition of cystathionase with propargylglycine reduced both 14 CO 2 production from [1- 14 C]CYS and ammonia plus urea nitrogen production from CYS by about 50%; CSA catabolism was not affected. Thus, cleavage of cyst(e)ine by cystathionase may be an important physiological pathway for CYS catabolism in the liver

Effects of secretagogues on ATP levels and protein carboxyl methylation in rat brain synaptosomes

International Nuclear Information System (INIS)

Bjorndahl, J.M.; Rutledge, C.O.

1986-01-01

The influence of various substances which are known to alter free intracellular calcium concentrations on protein carboxyl methyltransferase (PCM) activity was investigated in rat brain synaptosomes. The synaptosomes were labeled with L-[ 3 H]methionine and the 3 H-methyl esters of proteins were formed from the methyl donor S-[ 3 H]adenosyl-L-methionine ([ 3 H]AdoMet). The calcium ionophore A23187 and ouabain decreased PCM activity and the decrease produced by A23187 was antagonized by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and MnCl 2 . On the other hand, ruthenium red, an inhibitor of calcium uptake, stimulated PCM activity. These data suggest that PCM activity is inversely related to the free cytoplasmic calcium concentration. Veratridine, A23187 and elevated potassium ions decreased the levels of ATP and [ 3 H]AdoMet. The A23187-mediated decrease in ATP levels and the reduced [ 3 H]AdoMet formation was antagonized by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and MnCl 2 . Inhibition of metabolic activity of the synaptosomes by NaCN led to: decreased ATP levels; inhibition of [3H]AdoMet formation; and inhibition of PCM activity. These data suggest that the decrease in protein methylation produced by secretagogues is associated with an increase in the concentration of free intracellular calcium which results in a decrease in the metabolically active pool of ATP. This leads to a decreased rate of AdoMet formation, a cosubstrate for PCM and a resultant decrease in PCM activity

Cloning, functional expression and characterization of a bifunctional 3-hydroxybutanal dehydrogenase /reductase involved in acetone metabolism by Desulfococcus biacutus.

Science.gov (United States)

Frey, Jasmin; Rusche, Hendrik; Schink, Bernhard; Schleheck, David

2016-11-25

The strictly anaerobic, sulfate-reducing bacterium Desulfococcus biacutus can utilize acetone as sole carbon and energy source for growth. Whereas in aerobic and nitrate-reducing bacteria acetone is activated by carboxylation with CO 2 to acetoacetate, D. biacutus involves CO as a cosubstrate for acetone activation through a different, so far unknown pathway. Proteomic studies indicated that, among others, a predicted medium-chain dehydrogenase/reductase (MDR) superfamily, zinc-dependent alcohol dehydrogenase (locus tag DebiaDRAFT_04514) is specifically and highly produced during growth with acetone. The MDR gene DebiaDRAFT_04514 was cloned and overexpressed in E. coli. The purified recombinant protein required zinc as cofactor, and accepted NADH/NAD + but not NADPH/NADP + as electron donor/acceptor. The pH optimum was at pH 8, and the temperature optimum at 45 °C. Highest specific activities were observed for reduction of C 3 - C 5 -aldehydes with NADH, such as propanal to propanol (380 ± 15 mU mg -1 protein), butanal to butanol (300 ± 24 mU mg -1 ), and 3-hydroxybutanal to 1,3-butanediol (248 ± 60 mU mg -1 ), however, the enzyme also oxidized 3-hydroxybutanal with NAD + to acetoacetaldehyde (83 ± 18 mU mg -1 ). The enzyme might play a key role in acetone degradation by D. biacutus, for example as a bifunctional 3-hydroxybutanal dehydrogenase/reductase. Its recombinant production may represent an important step in the elucidation of the complete degradation pathway.

Kinetic Characterisation of Phosphofructokinase Purified from Setaria cervi: A Bovine Filarial Parasite

Directory of Open Access Journals (Sweden)

Bechan Sharma

2011-01-01

Full Text Available Phosphofructokinase (PFK, a regulatory enzyme in glycolytic pathway, has been purified to electrophoretic homogeneity from adult female Setaria cervi and partially characterized. For this enzyme, the Lineweaver-Burk's double reciprocal plots of initial rates and D-fructose-6-phosphate (F-6-P or Mg-ATP concentrations for varying values of cosubstrate concentration gave intersecting lines indicating that Km values for F-6-P (1.05 mM and ATP (3 μM were independent of each other. S. cervi PFK, when assayed at inhibitory concentration of ATP (>0.1 mM, exhibited sigmoidal behavior towards binding with F-6-P with a Hill coefficient (n value equal to 1.8 and 1.7 at 1.0 and 0.33 mM ATP, respectively. D-fructose-1,6-diphosphate (FDP competitively inhibited the filarial enzyme: Ki and Hill coefficient values being 0.18 μM and 2.0, respectively. Phosphoenolpyruvate (PEP also inhibited the enzyme competitively with the Ki value equal to 0.8 mM. The Hill coefficient values (>1.5 for F-6-P (at inhibitory concentration of ATP and FDP suggested its positive cooperative kinetics towards F-6-P and FDP, showing presence of more than one binding sites for these molecules in enzyme protein and allosteric nature of the filarial enzyme. The product inhibition studies gave us the only compatible mechanism of random addition process with a probable orientation of substrates and products on the enzyme surface.

The role of organic matter in the removal of emerging trace organic chemicals during managed aquifer recharge.

Science.gov (United States)

Rauch-Williams, T; Hoppe-Jones, C; Drewes, J E

2010-01-01

This study explored the effect of different bulk organic carbon matrices on the fate of trace organic chemicals (TOrC) during managed aquifer recharge (MAR). Infiltration through porous media was simulated in biologically active column experiments under aerobic and anoxic recharge conditions. Wastewater effluent derived organic carbon types, differing in hydrophobicity and biodegradability (i. e., hydrophobic acids, hydrophilic carbon, organic colloids), were used as feed substrates in the column experiments. These carbon substrates while fed at the same concentration differed in their ability to support soil biomass growth during porous media infiltration. Removal of degradable TOrC (with the exception of diclofenac and propyphenazone) was equal or better under aerobic versus anoxic porous media infiltration conditions. During the initial phase of infiltration, the presence of biodegradable organic carbon (BDOC) enhanced the decay of degradable TOrC by promoting soil biomass growth, suggesting that BDOC served as a co-substrate in a co-metabolic transformation of these contaminants. However, unexpected high removal efficiencies were observed for all degradable TOrC in the presence of low BDOC concentrations under well adopted oligotrophic conditions. It is hypothesized that removal under these conditions is caused by a specialized microbial community growing on refractory carbon substrates such as hydrophobic acids. Findings of this study reveal that the concentration and character of bulk organic carbon present in effluents affect the degradation efficiency for TOrC during recharge operation. Specifically aerobic, oligotrophic microbiological soil environments present favorable conditions for the transformation of TOrC, including rather recalcitrant compounds such as chlorinated flame retardants. (c) 2009 Elsevier Ltd. All rights reserved.

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.

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.)

3D modelling of groundwater flow and pollutant transport in the vicinity of the phenol-polluted mining lake ''Vollert-Sued'', Sachsen-Anhalt; Dreidimensionale Grundwasserstroemungs- und Schadstofftransportmodellierung im Umkreis des phenolverseuchten Tagebaurestloches Vollert-Sued, Sachsen-Anhalt

Energy Technology Data Exchange (ETDEWEB)

Eccarius, B.

2000-07-01

Schadstofftransport aufgebaut. Die fuer das Modell notwendigen Parameter wurden aus im Projektzeitraum durchgefuehrten Feldversuchen (Slug-Test, Pumpversuch, Seepage-Meter, Wasserstandsmessung) und Labormethoden (Korngroessenanalyse, Durchflussmesszellen- und Sorptionsversuch) sowie Literaturdaten gewonnen. Ausserdem wurden die hydrochemischen und isotopischen Eigenschafren des Grund- und Seewassers beschrieben. Mit Hilfe des 3D-Modells soll der aktuelle hydrogeologische Kenntnisstand umgesetzt und erlaeutert werden. Prognosen ueber den Verbleib, Transport oder Abbau der Phenole koennen erstellt werden. Zudem kann die zukuenftige Entwicklung der Grundwasserqualitaet simuliert werden, um eine Gefaehrdung von Trinkwasserbrunnen abzuschaetzen. Damit sollen Grundlagen fuer die Beurteilung der Notwendigkeit und die Moeglichkeit einer Grundwassersanierung gelegt werden. Das Projekt soll Modellcharakter fuer das methodische Vorgehen in analogen Schadensfaellen haben. (orig.)

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

Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

Science.gov (United States)

Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

2012-01-01

The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.

Exquisite Modulation of the Active Site of Methanocaldococcus jannaschii Adenylosuccinate Synthetase in Forward Reaction Complexes.

Science.gov (United States)

Karnawat, Vishakha; Mehrotra, Sonali; Balaram, Hemalatha; Puranik, Mrinalini

2016-05-03

In enzymes that conduct complex reactions involving several substrates and chemical transformations, the active site must reorganize at each step to complement the transition state of that chemical step. Adenylosuccinate synthetase (ADSS) utilizes a molecule each of guanosine 5'-monophosphate (GTP) and aspartate to convert inosine 5'-monophosphate (IMP) into succinyl adenosine 5'-monophosphate (sAMP) through several kinetic intermediates. Here we followed catalysis by ADSS through high-resolution vibrational spectral fingerprints of each substrate and intermediate involved in the forward reaction. Vibrational spectra show differential ligand distortion at each step of catalysis, and band positions of substrates are influenced by binding of cosubstrates. We found that the bound IMP is distorted toward its N1-deprotonated form even in the absence of any other ligands. Several specific interactions between GTP and active-site amino acid residues result in large Raman shifts and contribute substantially to intrinsic binding energy. When both IMP and GTP are simultaneously bound to ADSS, IMP is converted into an intermediate 6-phosphoryl inosine 5'-monophosphate (6-pIMP). The 6-pIMP·ADSS complex was found to be stable upon binding of the third ligand, hadacidin (HDA), an analogue of l-aspartate. We find that in the absence of HDA, 6-pIMP is quickly released from ADSS, is unstable in solution, and converts back into IMP. HDA allosterically stabilizes ADSS through local conformational rearrangements. We captured this complex and determined the spectra and structure of 6-pIMP in its enzyme-bound state. These results provide important insights into the exquisite tuning of active-site interactions with changing substrate at each kinetic step of catalysis.

Determination of biogas generation potential as a renewable energy source from supermarket wastes

International Nuclear Information System (INIS)

Alkanok, Gizem; Demirel, Burak; Onay, Turgut T.

2014-01-01

Highlights: • Disposal of supermarket wastes in landfills may contribute to environmental pollution. • High methane yields can be obtained from supermarket wastes by anaerobic co-digestion. • Fruit and vegetable wastes or dairy products wastes could individually be handled by a two-stage anaerobic process. • Buffering capacity, trace metal and C/N ratio are essential for digestion of supermarket wastes. - Abstract: 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 CH 4 /g VS added was obtained from anaerobic digestion of wastes (FVFW + DPW + MW + SW) at 10% TS, with 66.4% of methane (CH 4 ) 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 CH 4 /g VS added , respectively. When the wastes were digested alone without co-substrate addition, the highest methane yield of 0.40 L CH 4 /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

Biocatalysis of a Paclitaxel Analogue: Conversion of Baccatin III to N-Debenzoyl-N-(2-furoyl)paclitaxel and Characterization of an Amino Phenylpropanoyl CoA Transferase.

Science.gov (United States)

Thornburg, Chelsea K; Walter, Tyler; Walker, Kevin D

2017-11-07

In this study, we demonstrate an enzyme cascade reaction using a benzoate CoA ligase (BadA), a modified nonribosomal peptide synthase (PheAT), a phenylpropanoyltransferase (BAPT), and a benzoyltransferase (NDTNBT) to produce an anticancer paclitaxel analogue and its precursor from the commercially available biosynthetic intermediate baccatin III. BAPT and NDTNBT are acyltransferases on the biosynthetic pathway to the antineoplastic drug paclitaxel in Taxus plants. For this study, we addressed the recalcitrant expression of BAPT by expressing it as a soluble maltose binding protein fusion (MBP-BAPT). Further, the preparative-scale in vitro biocatalysis of phenylisoserinyl CoA using PheAT enabled thorough kinetic analysis of MBP-BAPT, for the first time, with the cosubstrate baccatin III. The turnover rate of MBP-BAPT was calculated for the product N-debenzoylpaclitaxel, a key intermediate to various bioactive paclitaxel analogues. MBP-BAPT also converted, albeit more slowly, 10-deacetylbaccatin III to N-deacyldocetaxel, a precursor of the pharmaceutical docetaxel. With PheAT available to make phenylisoserinyl CoA and kinetic characterization of MBP-BAPT, we used Michaelis-Menten parameters of the four enzymes to adjust catalyst and substrate loads in a 200-μL one-pot reaction. This multienzyme network produced a paclitaxel analogue N-debenzoyl-N-(2-furoyl)paclitaxel (230 ng) that is more cytotoxic than paclitaxel against certain macrophage cell types. Also in this pilot reaction, the versatile N-debenzoylpaclitaxel intermediate was made at an amount 20-fold greater than the N-(2-furoyl) product. This reaction network has great potential for optimization to scale-up production and is attractive in its regioselective O- and N-acylation steps that remove protecting group manipulations used in paclitaxel analogue synthesis.

Stereoselective sulfate conjugation of racemic 4-hydroxypropranolol by human and rat liver cytosol

Energy Technology Data Exchange (ETDEWEB)

Walle, T.; Walle, U.K. (Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston (USA))

1991-03-01

The objective of this study was to determine the stereochemistry of sulfoconjugation of a chiral phenolic amine drug, 4-hydroxypropranolol (HOP), by the human liver. The reaction was catalyzed by the 100,000 g cytosol as the phenolsulfotransferase (PST) enzyme source with PAP35S as the co-substrate. The enantiomers of the intact sulfate conjugate formed, (+)-HOP35S and (-)-HOP35S, were separated by HPLC and measured by liquid scintillation spectrometry. Complex velocity vs. substrate concentration curves were obtained with two peaks of activity, one at 3 microM (high affinity) and one at 500 microM (low affinity). The high-affinity reaction demonstrated a high degree of stereoselectivity. Whereas the affinity of the enantiomers for this reaction was identical, with a very low apparent KM value of 0.59 microM, the apparent Vmax value for (+)-HOPS formation was 4.6-fold higher than for (-)-HOPS. In sharp contrast, the low-affinity reaction, with an apparent KM of 65 microM, was not stereoselective. Inhibition of the high-affinity reaction by elevated temperature, but not by dichloronitrophenol, indicated that this activity was due to a monoamine form of PST. Inhibition of the low-affinity reaction by dichloronitrophenol, but not by elevated temperature, indicated that this activity was due to a phenol form of PST. As a comparison, experiments with the rat liver cytosol demonstrated only one activity, with apparent KM values of 50 microM for both enantiomers and opposite stereoselectivity in maximum velocity compared to humans, {plus minus}-HOPS ratio 0.72. The results of this study demonstrate stereoselectivity in human hepatic sulfation of a chiral phenolic amine, with clear differences between PST isoenzymes.

Steroid Hydroxylation by Basidiomycete Peroxygenases: a Combined Experimental and Computational Study

Science.gov (United States)

Babot, Esteban D.; del Río, José C.; Cañellas, Marina; Sancho, Ferran; Lucas, Fátima; Guallar, Víctor; Kalum, Lisbeth; Lund, Henrik; Gröbe, Glenn; Scheibner, Katrin; Ullrich, René; Hofrichter, Martin; Martínez, Angel T.

2015-01-01

The goal of this study is the selective oxyfunctionalization of steroids under mild and environmentally friendly conditions using fungal enzymes. With this purpose, peroxygenases from three basidiomycete species were tested for the hydroxylation of a variety of steroidal compounds, using H2O2 as the only cosubstrate. Two of them are wild-type enzymes from Agrocybe aegerita and Marasmius rotula, and the third one is a recombinant enzyme from Coprinopsis cinerea. The enzymatic reactions on free and esterified sterols, steroid hydrocarbons, and ketones were monitored by gas chromatography, and the products were identified by mass spectrometry. Hydroxylation at the side chain over the steroidal rings was preferred, with the 25-hydroxyderivatives predominating. Interestingly, antiviral and other biological activities of 25-hydroxycholesterol have been reported recently (M. Blanc et al., Immunity 38:106–118, 2013, http://dx.doi.org/10.1016/j.immuni.2012.11.004). However, hydroxylation in the ring moiety and terminal hydroxylation at the side chain also was observed in some steroids, the former favored by the absence of oxygenated groups at C-3 and by the presence of conjugated double bonds in the rings. To understand the yield and selectivity differences between the different steroids, a computational study was performed using Protein Energy Landscape Exploration (PELE) software for dynamic ligand diffusion. These simulations showed that the active-site geometry and hydrophobicity favors the entrance of the steroid side chain, while the entrance of the ring is energetically penalized. Also, a direct correlation between the conversion rate and the side chain entrance ratio could be established that explains the various reaction yields observed. PMID:25862224

Effect of laser radiation on the cultivation rate of the microalga Chlorella sorokiniana as a source of biofuel

Science.gov (United States)

Politaeva, N.; Smyatskaya, Y.; Slugin, V.; Toumi, A.; Bouabdelli, M.

2018-01-01

This article studies the influence of laser radiation on the growth of micro-algal biomass of Chlorella sorokiniana. The composition of nutrient medium and the effect the laser beam (2 and 5 cm diameter, 1, 5, 10, 15 and 20 minutes exposure time) for accelerated cultivation of microalgal biomass were studied. The source of laser radiation (LR) was a helium-neon laser with a nominal output power of 1.6 mW and a wavelength of 0.63 μm. The greatest increase in biomass was observed when LR was applied to a suspension of microalga Chlorella sorokiniana with a beam of 5 cm diameter for a time of 10, 15 and 20 minutes. The results of the microscopic study of the microalga cells show a significant increase in the number of cells after an exposure to LR with a beam diameter of 5 cm in diameter. These cells were characterized by a large vacuole, a thickened lipid shell and a large accumulation of metabolites prone to agglutination. This study proposed to obtain valuable components (lipids, carotenoids, and pectin) from the obtained biomass by extraction method and to use the residual biomass formed wastes, after the extraction of valuable components, as a co-substrate for anaerobic digestion to produce biogas. The composition of biogas consists mainly of methane and carbon dioxide. Methane is recommended to be used for economic needs in supplying the whole process with heat and electricity. The carbon dioxide formed during fermentation and after combustion of methane for energy production, is planned to be used as a carbon source in the cultivation of Chlorella sorokiniana for photoautotrophic biomass production.

Determination of biogas generation potential as a renewable energy source from supermarket wastes

Energy Technology Data Exchange (ETDEWEB)

Alkanok, Gizem; Demirel, Burak, E-mail: burak.demirel@boun.edu.tr; Onay, Turgut T.

2014-01-15

Highlights: • Disposal of supermarket wastes in landfills may contribute to environmental pollution. • High methane yields can be obtained from supermarket wastes by anaerobic co-digestion. • Fruit and vegetable wastes or dairy products wastes could individually be handled by a two-stage anaerobic process. • Buffering capacity, trace metal and C/N ratio are essential for digestion of supermarket wastes. - Abstract: 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 CH{sub 4}/g VS{sub added} was obtained from anaerobic digestion of wastes (FVFW + DPW + MW + SW) at 10% TS, with 66.4% of methane (CH{sub 4}) 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 CH{sub 4}/g VS{sub added}, respectively. When the wastes were digested alone without co-substrate addition, the highest methane yield of 0.40 L CH{sub 4}/g VS{sub 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.

Analyzing key constraints to biogas production from crop residues and manure in the EU—A spatially explicit model

Science.gov (United States)

Persson, U. Martin

2017-01-01

This paper presents a spatially explicit method for making regional estimates of the potential for biogas production from crop residues and manure, accounting for key technical, biochemical, environmental and economic constraints. Methods for making such estimates are important as biofuels from agricultural residues are receiving increasing policy support from the EU and major biogas producers, such as Germany and Italy, in response to concerns over unintended negative environmental and social impacts of conventional biofuels. This analysis comprises a spatially explicit estimate of crop residue and manure production for the EU at 250 m resolution, and a biogas production model accounting for local constraints such as the sustainable removal of residues, transportation of substrates, and the substrates’ biochemical suitability for anaerobic digestion. In our base scenario, the EU biogas production potential from crop residues and manure is about 0.7 EJ/year, nearly double the current EU production of biogas from agricultural substrates, most of which does not come from residues or manure. An extensive sensitivity analysis of the model shows that the potential could easily be 50% higher or lower, depending on the stringency of economic, technical and biochemical constraints. We find that the potential is particularly sensitive to constraints on the substrate mixtures’ carbon-to-nitrogen ratio and dry matter concentration. Hence, the potential to produce biogas from crop residues and manure in the EU depends to large extent on the possibility to overcome the challenges associated with these substrates, either by complementing them with suitable co-substrates (e.g. household waste and energy crops), or through further development of biogas technology (e.g. pretreatment of substrates and recirculation of effluent). PMID:28141827

Analyzing key constraints to biogas production from crop residues and manure in the EU-A spatially explicit model.

Science.gov (United States)

Einarsson, Rasmus; Persson, U Martin

2017-01-01

This paper presents a spatially explicit method for making regional estimates of the potential for biogas production from crop residues and manure, accounting for key technical, biochemical, environmental and economic constraints. Methods for making such estimates are important as biofuels from agricultural residues are receiving increasing policy support from the EU and major biogas producers, such as Germany and Italy, in response to concerns over unintended negative environmental and social impacts of conventional biofuels. This analysis comprises a spatially explicit estimate of crop residue and manure production for the EU at 250 m resolution, and a biogas production model accounting for local constraints such as the sustainable removal of residues, transportation of substrates, and the substrates' biochemical suitability for anaerobic digestion. In our base scenario, the EU biogas production potential from crop residues and manure is about 0.7 EJ/year, nearly double the current EU production of biogas from agricultural substrates, most of which does not come from residues or manure. An extensive sensitivity analysis of the model shows that the potential could easily be 50% higher or lower, depending on the stringency of economic, technical and biochemical constraints. We find that the potential is particularly sensitive to constraints on the substrate mixtures' carbon-to-nitrogen ratio and dry matter concentration. Hence, the potential to produce biogas from crop residues and manure in the EU depends to large extent on the possibility to overcome the challenges associated with these substrates, either by complementing them with suitable co-substrates (e.g. household waste and energy crops), or through further development of biogas technology (e.g. pretreatment of substrates and recirculation of effluent).

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

Science.gov (United States)

Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

2017-08-30

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

OxDBase: a database of oxygenases involved in biodegradation

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Raghava Gajendra PS

2009-04-01

Full Text Available Abstract Background Oxygenases belong to the oxidoreductive group of enzymes (E.C. Class 1, which oxidize the substrates by transferring oxygen from molecular oxygen (O2 and utilize FAD/NADH/NADPH as the co-substrate. Oxygenases can further be grouped into two categories i.e. monooxygenases and dioxygenases on the basis of number of oxygen atoms used for oxidation. They play a key role in the metabolism of organic compounds by increasing their reactivity or water solubility or bringing about cleavage of the aromatic ring. Findings We compiled a database of biodegradative oxygenases (OxDBase which provides a compilation of the oxygenase data as sourced from primary literature in the form of web accessible database. There are two separate search engines for searching into the database i.e. mono and dioxygenases database respectively. Each enzyme entry contains its common name and synonym, reaction in which enzyme is involved, family and subfamily, structure and gene link and literature citation. The entries are also linked to several external database including BRENDA, KEGG, ENZYME and UM-BBD providing wide background information. At present the database contains information of over 235 oxygenases including both dioxygenases and monooxygenases. This database is freely available online at http://www.imtech.res.in/raghava/oxdbase/. Conclusion OxDBase is the first database that is dedicated only to oxygenases and provides comprehensive information about them. Due to the importance of the oxygenases in chemical synthesis of drug intermediates and oxidation of xenobiotic compounds, OxDBase database would be very useful tool in the field of synthetic chemistry as well as bioremediation.

Asymmetric reduction of ketones and β-keto esters by (S)-1-phenylethanol dehydrogenase from denitrifying bacterium Aromatoleum aromaticum.

Science.gov (United States)

Dudzik, A; Snoch, W; Borowiecki, P; Opalinska-Piskorz, J; Witko, M; Heider, J; Szaleniec, M

2015-06-01

Enzyme-catalyzed enantioselective reductions of ketones and keto esters have become popular for the production of homochiral building blocks which are valuable synthons for the preparation of biologically active compounds at industrial scale. Among many kinds of biocatalysts, dehydrogenases/reductases from various microorganisms have been used to prepare optically pure enantiomers from carbonyl compounds. (S)-1-phenylethanol dehydrogenase (PEDH) was found in the denitrifying bacterium Aromatoleum aromaticum (strain EbN1) and belongs to the short-chain dehydrogenase/reductase family. It catalyzes the stereospecific oxidation of (S)-1-phenylethanol to acetophenone during anaerobic ethylbenzene mineralization, but also the reverse reaction, i.e., NADH-dependent enantioselective reduction of acetophenone to (S)-1-phenylethanol. In this work, we present the application of PEDH for asymmetric reduction of 42 prochiral ketones and 11 β-keto esters to enantiopure secondary alcohols. The high enantioselectivity of the reaction is explained by docking experiments and analysis of the interaction and binding energies of the theoretical enzyme-substrate complexes leading to the respective (S)- or (R)-alcohols. The conversions were carried out in a batch reactor using Escherichia coli cells with heterologously produced PEDH as whole-cell catalysts and isopropanol as reaction solvent and cosubstrate for NADH recovery. Ketones were converted to the respective secondary alcohols with excellent enantiomeric excesses and high productivities. Moreover, the progress of product formation was studied for nine para-substituted acetophenone derivatives and described by neural network models, which allow to predict reactor behavior and provides insight on enzyme reactivity. Finally, equilibrium constants for conversion of these substrates were derived from the progress curves of the reactions. The obtained values matched very well with theoretical predictions.

ACCUMULATION OF POLYHYDROXYALKANOIC ACIDS BY AZOTOBACTER CHROOCOCCUM MAL-201 FROM ORGANIC WASTE

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Soma Pal Saha

2013-08-01

Full Text Available Azotobacter chroococcum MAL-201 (MTCC 3853, a free-living nitrogen-fixing bacterium accumulated intracellular poly(3-hydroxybutyric acid [P(3HB] accounting 69% of cell dry weight (CDW when grown in nitrogrn-free Stockdale medium containing 2% (w/v glucose. It also produced copolymer of poly(3-hydroxybutyrate co-3-hydroxyvalerate [P(3HB-co-3HV] using glucose as primary carbon source and valerate cas cosubstrate. To make the polymer production cost effective four types of waste material of different origin were tested for growth and polymer production. Stockdale medium supplemented with 1% (w/v waste materials failed to yield good growth and polymer accumulation. Two–step cultivation was adopted for better growth and enhanced polymer accumulation. The candy factory waste was most suitable for synthesis of P(3HB accounting 17.8 and 40.58% using single and two-step cultivation conditions respectively. Wastes of domestic and poultry origin produced P(3HB-co-3HV with 3HV content 28.8 and 21.5 mol% respectively in two-step cultivation. Increase concentration of these wastes resulted in further upliftment of 3HV content of polymer with reduced growth and polymer accumulation. However, at optimum incubation the strain MAL-201 cells accumulated P(3HB 48.5% of CDW (at 40h from candy factory waste and P(3HB-co-3HV 24.75 % of CDW with 3HV 34.65 mol % from domestic waste. Intrinsic viscosity, molecular weight and thermal degradation of the polymers accumulated in the cells grown in glucose, glucose with valerate and glucose with waste were compared.

Possible pathophysiological roles of transglutaminase-catalyzed reactions in the pathogenesis of human neurodegenerative diseases

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Enrica Serretiello

2015-09-01

Full Text Available Transglutaminases (TG, E.C. 2.3.2.13 are related and ubiquitous enzymes that catalyze the cross linking of a glutaminyl residue of a protein/peptide substrate to a lysyl residue of a protein/peptide co-substrate. These enzymes are also capable of catalyzing other post-translational reactions important for cell life. The distribution and the physiological roles of human TGs have been widely studied in numerous cell types and tissues and recently their roles in several diseases have begun to be identified. It has been hypothesized that transglutaminase activity is directly involved in the pathogenetic mechanisms responsible for several human diseases. In particular, tissue TG (tTG, TG2, a member of the TG enzyme family, has been recently shown to be involved in the molecular mechanisms responsible for a very widespread human pathology, Celiac Disease (CD, one of the most common food intolerances described in the western population. The main food agent that provokes the strong and diffuse clinical symptoms has been known for several years to be gliadin, a protein present in a very large number of human foods derived from vegetables. Recently, some biochemical and immunological aspects of this very common disease have been clarified, and “tissue” transglutaminase, a multifunctional and ubiquitous enzyme, has been identified as one of the major factors. The aim of this review is to summarize the most recent findings concerning the relationships between the biochemical properties of the transglutaminase activity and the basic molecular mechanisms responsible for some human diseases, with particular reference to neuropsychiatric disorders. Possible molecular links between CD and neuropsychiatric disorders, and the use of transglutaminase inhibitors are also discussed.

The reduced bioavailability of copper by nano-TiO₂ attenuates the toxicity to Microcystis aeruginosa.

Science.gov (United States)

Chen, Jinyuan; Qian, Yi; Li, Herong; Cheng, Yanhong; Zhao, Meirong

2015-08-01

Nano-TiO2 is a widely applied nanoparticle (NPs) and co-exists with other pollutants such as heavy metals in aquatic environments. However, minimal knowledge is available concerning the ecological risk of these mixtures. Our study reported that at no toxic effect concentrations of TiO2 nanoparticles (5 mg/L), the toxicity of Cu ions to the algae Microcystis aeruginosa was significantly attenuated by TiO2 nanoparticles. Specifically, the concentration of photosynthetic pigments (i.e., concentration of Chla) increased 37% when comparing only Cu ions treated and the nano-TiO2-Cu co-incubation. The levels of phycocyanin (PC), allophycocyanin (APC), phycoerythrin (PE), and phycobiliprotein (PBPs) were also recovered at levels ranging from 23 to 35% after 72 h. For oxidative indexes, the decreased activities of the superoxide dismutase (SOD), peroxidase (POD) content, and malondialdehyde (MDA) with the existence of nano-TiO2 displayed a lower level compared to Cu ions treatment only at 24 and 48 h. This toxicity attenuation can be confirmed by subcellular structures because the impairment to cellular membranes and organelles reduced with the presence of nano-TiO2. The potential mechanisms of the antagonism between the nano-TiO2 and Cu ions can be partially attributed to the sorption of copper onto TiO2 nanoparticles, which fitted the Freundlich isotherm (coefficient = 0.967). The decreased bioavailability of Cu ions protected algae cells from being attacked by free Cu ions. Given the abundance of released nanoparticles and unique physicochemical property of nanoparticles, our results elucidated the ecosafety of nanoparticles and co-substrates in aquatic systems.

Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

Energy Technology Data Exchange (ETDEWEB)

Panichnumsin, Pornpan [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Thungkru, Bangkok 10140 (Thailand); Excellent Center of Waste Utilization and Management, National Center for Genetic Engineering and Biotechnology, Bangkhuntien, Bangkok 10150 (Thailand); Nopharatana, Annop [Pilot Plant Development and Training Institute, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand); Ahring, Birgitte [AAU, Copenhagen Institute of Technology, Lautrupvang 15, 2750 Ballerup (Denmark); Chaiprasert, Pawinee [School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand)

2010-08-15

Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m{sup -3} d{sup -1} and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g{sup -1} VS{sub added} and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity. (author)

Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

International Nuclear Information System (INIS)

Panichnumsin, Pornpan; Nopharatana, Annop; Ahring, Birgitte; Chaiprasert, Pawinee

2010-01-01

Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 o C) and at a constant OLR of 3.5 kg VS m -3 d -1 and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g -1 VS added and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity.

Surfactant producing TNT-degrading microorganisms for bioremediation

Energy Technology Data Exchange (ETDEWEB)

Vorobyov, A.; Marchenko, A.; Rudneva, O.; Borovick, R. [Research Center for Toxicology and Hygienic Regulation of Biopreparations, Serpukhov, Moscow region (Russian Federation); Radosevich, M. [Univ. of Delaware, Newark (United States). Dept. of Plant and Soil Sciences

2003-07-01

In general the biodegradation of nitroaromatic hydrocarbons is influenced by their bioavailability. 2,4,6-trinitrotoluene is very poorly soluble in water. TNT is easily adsorbed to clay or humus fractions in the soil, and pass very slowly to the aqueous phase, where microorganisms metabolize it. Biosurfactants that increase TNT solubility and improve its bioavailability can thereby accelerate degradation. Pure cultures of microorganisms-TNT degraders were isolated by the method of enrichment cultures from samples of different-type soil contaminated by TNT (soddy-podzol, black earth, and gray forest ones). From 28 soil samples 35 isolates of microorganisms degrading TNT were taken. The isolated soil samples had been tested for availability of microbial activity towards TNT. By10 g of air-dried soil, 10 ml of distilled water, and 2 mg of TNT were placed into 750 ml shaken flasks. The flasks were incubated at 150 rev/min and 24 C. Glucose, sodium succinate or sodium acetate had been used as co-substrates. The ability of the strains to produce surfactants was studied by drop collapsing test and direct measuring of surface tension of cultural liquid after cultivation with TNT. Cells of the strains were cultivated on solid and liquid nutrient media. For drop collapsing test the cells were cultivated on solid nutrient media; the separated colonies were suspended in distilled water. Drop sustainability test ws conducted on a standard 96-well plates coated with a thin layer of vaseline oil. Surface tension of cultural liquid ws measured after cultivation of strains in the presence of TNT with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. (orig.)

Analyzing key constraints to biogas production from crop residues and manure in the EU-A spatially explicit model.

Directory of Open Access Journals (Sweden)

Rasmus Einarsson

Full Text Available This paper presents a spatially explicit method for making regional estimates of the potential for biogas production from crop residues and manure, accounting for key technical, biochemical, environmental and economic constraints. Methods for making such estimates are important as biofuels from agricultural residues are receiving increasing policy support from the EU and major biogas producers, such as Germany and Italy, in response to concerns over unintended negative environmental and social impacts of conventional biofuels. This analysis comprises a spatially explicit estimate of crop residue and manure production for the EU at 250 m resolution, and a biogas production model accounting for local constraints such as the sustainable removal of residues, transportation of substrates, and the substrates' biochemical suitability for anaerobic digestion. In our base scenario, the EU biogas production potential from crop residues and manure is about 0.7 EJ/year, nearly double the current EU production of biogas from agricultural substrates, most of which does not come from residues or manure. An extensive sensitivity analysis of the model shows that the potential could easily be 50% higher or lower, depending on the stringency of economic, technical and biochemical constraints. We find that the potential is particularly sensitive to constraints on the substrate mixtures' carbon-to-nitrogen ratio and dry matter concentration. Hence, the potential to produce biogas from crop residues and manure in the EU depends to large extent on the possibility to overcome the challenges associated with these substrates, either by complementing them with suitable co-substrates (e.g. household waste and energy crops, or through further development of biogas technology (e.g. pretreatment of substrates and recirculation of effluent.

Degradation alternatives for a commercial fungicide in water: biological, photo-Fenton, and coupled biological photo-Fenton processes.

Science.gov (United States)

López-Loveira, Elsa; Ariganello, Federico; Medina, María Sara; Centrón, Daniela; Candal, Roberto; Curutchet, Gustavo

2017-11-01

Imazalil (IMZ) is a widely used fungicide for the post-harvest treatment of citrus, classified as "likely to be carcinogenic in humans" for EPA, that can be only partially removed by conventional biological treatment. Consequently, specific or combined processes should be applied to prevent its release to the environment. Biological treatment with adapted microorganism consortium, photo-Fenton, and coupled biological photo-Fenton processes were tested as alternatives for the purification of water containing high concentration of the fungicide and the coadjutants present in the commercial formulation. IMZ-resistant consortium with the capacity to degrade IMZ in the presence of a C-rich co-substrate was isolated from sludge coming from a fruit packaging company wastewater treatment plant. This consortium was adapted to resist and degrade the organics present in photo-Fenton-oxidized IMZ water solution. Bacteria colonies from the consortia were isolated and identified. The effect of H 2 O 2 initial concentration and dosage on IMZ degradation rate, average oxidation state (AOS), organic acid concentration, oxidation, and mineralization percentage after photo-Fenton process was determined. The application of biological treatment to the oxidized solutions notably decreased the total organic carbon (TOC) in solution. The effect of the oxidation degree, limited by H 2 O 2 concentration and dosage, on the percentage of mineralization obtained after the biological treatment was determined and explained in terms of changes in AOS. The concentration of H 2 O 2 necessary to eliminate IMZ by photo-Fenton and to reduce TOC and chemical oxygen demand (COD) by biological treatment, in order to allow the release of the effluents to rivers with different flows, was estimated.

A novel experimental approach for the determination of the photooxidative decay of semivolatile pesticides and POPs adsorbed on single levitated particles; Aufbau eines Messverfahrens zum photo-oxidativen Abbau von semivolatilen Pflanzenschutzmitteln und POPs an levitierten Einzelpartikeln

Energy Technology Data Exchange (ETDEWEB)

Ruehl, E.

2002-08-01

A novel experimental approach has been developed that permits to measure in the laboratory the atmospheric decay of low volatile, particle-bound compounds (pesticides, persistent organic pollutants (POP)) which react efficiently with OH-radicals in the atmosphere. The experimental approach makes use of trapped micro- and nanoparticles which are coated by monolayers of the low volatile compounds. Trapping is accomplished by storing the particles in an electrodynamic trap, which is surrounded by a controlled atmosphere. The temperature, pressure, humidity, and the chemical composition of the atmosphere can be adjusted to the atmospheric environment of interest. The particles can be exposed to reactive trace gases, such as OH radicals or ozone. The chemically induced changes of the adsorbates are time-resolved monitored by Raman spectroscopy. As a result, chemical processes, reaction products, as well as evaporation from the particle surface can be investigated. Alternatively, Fourier-transform infrared spectroscopy can be used for the detection of such time resolved processes. The experiments allow us to derive kinetic data of particle-bound low volatile compounds. We have constructed and characterized all devices and components that are required for this novel experimental approach. This included a suitable particle trap, sources of OH radicals, and the efficient detection of time-resolved Raman spectra of stored particles. The components were commissioned by using simple, but realistic test systems. Raman spectra of particle-bound pesticides were measured and first kinetic experiments were performed. The setup is now ready to use for systems of environmental interest. (orig.) [German] Es wurde ein neues experimentelles Verfahren zur quantitativen Bestimmung des Abbaus von partikelgebundenen gering volatilen Substanzen (Pflanzenschutzmittel, persistente organische Schadstoffe (POP)) durch OH-Radikale aufgebaut. Der experimentelle Ansatz nutzt beruehrungslos gespeicherte Mikro- und Nanopartikel, auf deren Oberflaeche die zu untersuchenden Substanzen in Monolagen adsorbiert sind. Die beruehrungslose Speicherung der Partikel gelingt in einer elektrodynamischen Falle, in der die Temperatur, Luftdruck, Luftfeuchte und die Zusammensetzung der Atmosphaere kontrolliert einstellbar ist. Die Partikel werden reaktiven Gasen, wie OH-Radikalen, ausgesetzt. Die induzierten Veraenderungen der adsorbierten Substanzen werden zeitaufgeloest mit Hilfe der Raman-Spektroskopie verfolgt, so dass chemische Prozesse, die entstehenden Reaktionsprodukte sowie auch Abdampfverluste von der Partikeloberflaeche quantifiziert werden koennen. Alternativ kann auch die Fourier-Transform-Infrarot-Spektroskopie zum spezifischen Nachweis genutzt werden. Mit den Experimenten lassen sich reaktionskinetische Daten zum indirekten Photoabbau schwerfluechtiger Substanzen als Funktion der Umgebungsbedingungen ableiten. Im Zuge des Vorhabens wurden die notwendigen experimentellen Voraussetzungen geschaffen und die hierfuer konstruierten Komponenten anhand von Testsystemen im Hinblick auf ihre Einsetzbarkeit charakterisiert. Erste Experimente zur Reaktionskinetik belegen die Funktionstuechtigkeit des neuen Verfahrens. (orig.)

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

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.)

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.)

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biodegradation of polycyclic aromatic hydrocarbons: Using microbial bioelectrochemical systems to overcome an impasse.

Science.gov (United States)

Kronenberg, Maria; Trably, Eric; Bernet, Nicolas; Patureau, Dominique

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) are hardly biodegradable carcinogenic organic compounds. Bioremediation is a commonly used method for treating PAH contaminated environments such as soils, sediment, water bodies and wastewater. However, bioremediation has various drawbacks including the low abundance, diversity and activity of indigenous hydrocarbon degrading bacteria, their slow growth rates and especially a limited bioavailability of PAHs in the aqueous phase. Addition of nutrients, electron acceptors or co-substrates to enhance indigenous microbial activity is costly and added chemicals often diffuse away from the target compound, thus pointing out an impasse for the bioremediation of PAHs. A promising solution is the adoption of bioelectrochemical systems. They guarantee a permanent electron supply and withdrawal for microorganisms, thereby circumventing the traditional shortcomings of bioremediation. These systems combine biological treatment with electrochemical oxidation/reduction by supplying an anode and a cathode that serve as an electron exchange facility for the biocatalyst. Here, recent achievements in polycyclic aromatic hydrocarbon removal using bioelectrochemical systems have been reviewed. This also concerns PAH precursors: total petroleum hydrocarbons and diesel. Removal performances of PAH biodegradation in bioelectrochemical systems are discussed, focussing on configurational parameters such as anode and cathode designs as well as environmental parameters like porosity, salinity, adsorption and conductivity of soil and sediment that affect PAH biodegradation in BESs. The still scarcely available information on microbiological aspects of bioelectrochemical PAH removal is summarised here. This comprehensive review offers a better understanding of the parameters that affect the removal of PAHs within bioelectrochemical systems. In addition, future experimental setups are proposed in order to study syntrophic relationships between PAH

Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms

Energy Technology Data Exchange (ETDEWEB)

Nancharaiah, Y.V., E-mail: venkatany@gmail.com; Kiran Kumar Reddy, G.; Krishna Mohan, T.V.; Venugopalan, V.P.

2015-02-11

Graphical abstract: - Highlights: • Aerobic granular biomass was cultivated by feeding TBP along with acetate. • Rapid biodegradation of TBP when used as a co-substrate or as the sole carbon source. • Biodegradation of 2 mM TBP in 5 h with degradation rate of 0.4 μmol mL{sup −1} h{sup −1}. • High phosphatase activity was observed in TBP-degrading granular biomass. • n-Butanol, hydrolyzed product of TBP, was rapidly metabolized by aerobic granules. - Abstract: Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2 mM of TBP was achieved within 5 h with a degradation rate of 0.4 μmol mL{sup −1} h{sup −1}. TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites.

Insulin promotes diacylglycerol kinase activation by different mechanisms in rat cerebral cortex synaptosomes.

Science.gov (United States)

Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

2006-10-01

The mechanism by which insulin increases diacylglycerol kinase (DAGK) activity has been studied in cerebral cortex (CC) synaptosomes from adult (3-4 months of age) rats. The purpose of this study was to identify the role of phospholipases C and D (PLC and PLD) in DAGK activation by insulin. Neomycin, an inhibitor of PLC phosphatidylinositol-bisphosphate (PIP2) specific; ethanol, an inhibitor of phosphatidic acid (PA) formation by the promotion of a transphosphatidyl reaction of phosphatidylcholine phospholipase D (PC-PLD); and DL propranolol, an inhibitor of phosphatidate phosphohydrolase (PAP), were used in this study. Insulin (0.1 microM) shielded an increase in PA synthesis by [32P] incorporation using [gamma-32P]ATP as substrate and endogenous diacylglycerol (DAG) as co-substrate. This activated synthesis was strongly inhibited either by ethanol or DL propranolol. Pulse chase experiments also showed a PIP2-PLC activation within 1 min exposure to insulin. When exogenous unsaturated 18:0-20:4 DAG was present, insulin increased PA synthesis significantly. However, this stimulatory effect was not observed in the presence of exogenous saturated (di-16:0). In the presence of R59022, a selective DAGK inhibitor, insulin exerted no stimulatory effect on [32P]PA formation, suggesting a strong relationship between increased PA formation by insulin and DAGK activity. These data indicate that the increased synthesis of PA by insulin could be mediated by the activation of both a PC-PLD pathway to provide DAG and a direct DAGK activation that is associated to the use of 18:0-20:4 DAG species. PIP2-PLC activation may contribute at least partly to the insulin effect on DAGK activity. Copyright 2006 Wiley-Liss, Inc.

Process optimization for enhancing production of cis-4-hydroxy-L-proline by engineered Escherichia coli.

Science.gov (United States)

Chen, Kequan; Pang, Yang; Zhang, Bowen; Feng, Jiao; Xu, Sheng; Wang, Xin; Ouyang, Pingkai

2017-11-22

Understanding the bioprocess limitations is critical for the efficient design of biocatalysts to facilitate process feasibility and improve process economics. In this study, a proline hydroxylation process with recombinant Escherichia coli expressing L-proline cis-4-hydroxylase (SmP4H) was investigated. The factors that influencing the metabolism of microbial hosts and process economics were focused on for the optimization of cis-4-hydroxy-L-proline (CHOP) production. In recombinant E. coli, SmP4H synthesis limitation was observed. After the optimization of expression system, CHOP production was improved in accordance with the enhanced SmP4H synthesis. Furthermore, the effects of the regulation of proline uptake and metabolism on whole-cell catalytic activity were investigated. The improved CHOP production by repressing putA gene responsible for L-proline degradation or overexpressing L-proline transporter putP on CHOP production suggested the important role of substrate uptake and metabolism on the whole-cell biocatalyst efficiency. Through genetically modifying these factors, the biocatalyst activity was significantly improved, and CHOP production was increased by twofold. Meanwhile, to further improve process economics, a two-strain coupling whole-cell system was established to supply co-substrate (α-ketoglutarate, α-KG) with a cheaper chemical L-glutamate as a starting material, and 13.5 g/L of CHOP was successfully produced. In this study, SmP4H expression, and L-proline uptake and degradation, were uncovered as the hurdles for microbial production of CHOP. Accordingly, the whole-cell biocatalysts were metabolically engineered for enhancing CHOP production. Meanwhile, a two-strain biotransformation system for CHOP biosynthesis was developed aiming at supplying α-KG more economically. Our work provided valuable insights into the design of recombinant microorganism to improve the biotransformation efficiency that catalyzed by Fe

Regulation of NAD+ metabolism, signaling and compartmentalization in the yeast Saccharomyces cerevisiae

Science.gov (United States)

Kato, Michiko; Lin, Su-Ju

2014-01-01

Pyridine nucleotides are essential coenzymes in many cellular redox reactions in all living systems. In addition to functioning as a redox carrier, NAD+ is also a required co-substrate for the conserved sirtuin deacetylases. Sirtuins regulate transcription, genome maintenance and metabolism and function as molecular links between cells and their environment. Maintaining NAD+ homeostasis is essential for proper cellular function and aberrant NAD+ metabolism has been implicated in a number of metabolic- and age-associated diseases. Recently, NAD+ metabolism has been linked to the phosphate-responsive signaling pathway (PHO pathway) in the budding yeast Saccharomyces cerevisiae. Activation of the PHO pathway is associated with the production and mobilization of the NAD+ metabolite nicotinamide riboside (NR), which is mediated in part by PHO-regulated nucleotidases. Cross-regulation between NAD+ metabolism and the PHO pathway has also been reported; however, detailed mechanisms remain to be elucidated. The PHO pathway also appears to modulate the activities of common downstream effectors of multiple nutrient-sensing pathways (Ras-PKA, TOR, Sch9/AKT). These signaling pathways were suggested to play a role in calorie restriction-mediated beneficial effects, which have also been linked to Sir2 function and NAD+ metabolism. Here, we discuss the interactions of these pathways and their potential roles in regulating NAD+ metabolism. In eukaryotic cells, intracellular compartmentalization facilitates the regulation of enzymatic functions and also concentrates or sequesters specific metabolites. Various NAD+-mediated cellular functions such as mitochondrial oxidative phosphorylation are compartmentalized. Therefore, we also discuss several key players functioning in mitochondrial, cytosolic and vacuolar compartmentalization of NAD+ intermediates, and their potential roles in NAD+ homeostasis. To date, it remains unclear how NAD+ and NAD+ intermediates shuttle between different

Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms

International Nuclear Information System (INIS)

Nancharaiah, Y.V.; Kiran Kumar Reddy, G.; Krishna Mohan, T.V.; Venugopalan, V.P.

2015-01-01

Graphical abstract: - Highlights: • Aerobic granular biomass was cultivated by feeding TBP along with acetate. • Rapid biodegradation of TBP when used as a co-substrate or as the sole carbon source. • Biodegradation of 2 mM TBP in 5 h with degradation rate of 0.4 μmol mL −1 h −1 . • High phosphatase activity was observed in TBP-degrading granular biomass. • n-Butanol, hydrolyzed product of TBP, was rapidly metabolized by aerobic granules. - Abstract: Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2 mM of TBP was achieved within 5 h with a degradation rate of 0.4 μmol mL −1 h −1 . TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites

A techno-economic evaluation of a biomass energy conversion park

Energy Technology Data Exchange (ETDEWEB)

Van Dael, M.; Van Passel, S.; Witters, N. [Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek (Belgium); Pelkmans, L.; Guisson, R. [VITO, Boeretang 200, 2400 Mol (Belgium); Reumermann, P. [BTG Biomass Technology Group, Josink Esweg 34, 7545 PN Enschede (Netherlands); Marquez Luzardo, N. [School of Life Sciences and Environmental Technology, Avans Hogeschool, Hogeschoollaan 1, 4800 RA Breda (Netherlands); Broeze, J. [Agrotechnology and Food Sciences Group, Wageningen University, Bomenweg 2, 6703 HD Wageningen (Netherlands)

2013-04-15

Biomass as a renewable energy source has many advantages and is therefore recognized as one of the main renewable energy sources to be deployed in order to attain the target of 20% renewable energy use of final energy consumption by 2020 in Europe. In this paper the concept of a biomass Energy Conversion Park (ECP) is introduced. A biomass ECP can be defined as a synergetic, multi-dimensional biomass conversion site with a highly integrated set of conversion technologies in which a multitude of regionally available biomass (residue) sources are converted into energy and materials. A techno-economic assessment is performed on a case study in the Netherlands to illustrate the concept and to comparatively assess the highly integrated system with two mono-dimensional models. The three evaluated models consist of (1) digestion of the organic fraction of municipal solid waste, (2) co-digestion of manure and co-substrates, and (3) integration. From a socio-economic point of view it can be concluded that it is economically and energetically more interesting to invest in the integrated model than in two separate models. The integration is economically feasible and environmental benefits can be realized. For example, the integrated model allows the implementation of a co-digester. Unmanaged manure would otherwise represent a constant pollution risk. However, from an investor's standpoint one should firstly invest in the municipal solid waste digester since the net present value (NPV) of this mono-dimensional model is higher than that of the multi-dimensional model. A sensitivity analysis is performed to identify the most influencing parameters. Our results are of interest for companies involved in the conversion of biomass. The conclusions are useful for policy makers when deciding on policy instruments concerning manure processing or biogas production.

Decoding how a soil bacterium extracts building blocks and metabolic energy from ligninolysis provides road map for lignin valorization

Science.gov (United States)

Varman, Arul M.; He, Lian; Follenfant, Rhiannon; Wu, Weihua; Wemmer, Sarah; Wrobel, Steven A.; Tang, Yinjie J.; Singh, Seema

2016-01-01

Sphingobium sp. SYK-6 is a soil bacterium boasting a well-studied ligninolytic pathway and the potential for development into a microbial chassis for lignin valorization. An improved understanding of its metabolism will help researchers in the engineering of SYK-6 for the production of value-added chemicals through lignin valorization. We used 13C-fingerprinting, 13C metabolic flux analysis (13C-MFA), and RNA-sequencing differential expression analysis to uncover the following metabolic traits: (i) SYK-6 prefers alkaline conditions, making it an efficient host for the consolidated bioprocessing of lignin, and it also lacks the ability to metabolize sugars or organic acids; (ii) the CO2 release (i.e., carbon loss) from the ligninolysis-based metabolism of SYK-6 is significantly greater than the CO2 release from the sugar-based metabolism of Escherichia coli; (iii) the vanillin catabolic pathway (which is the converging point of majority of the lignin catabolic pathways) is coupled with the tetrahydrofolate-dependent C1 pathway that is essential for the biosynthesis of serine, histidine, and methionine; (iv) catabolic end products of lignin (pyruvate and oxaloacetate) must enter the tricarboxylic acid (TCA) cycle first and then use phosphoenolpyruvate carboxykinase to initiate gluconeogenesis; and (v) 13C-MFA together with RNA-sequencing differential expression analysis establishes the vanillin catabolic pathway as the major contributor of NAD(P)H synthesis. Therefore, the vanillin catabolic pathway is essential for SYK-6 to obtain sufficient reducing equivalents for its healthy growth; cosubstrate experiments support this finding. This unique energy feature of SYK-6 is particularly interesting because most heterotrophs rely on the transhydrogenase, the TCA cycle, and the oxidative pentose phosphate pathway to obtain NADPH. PMID:27634497

Reactor performance and energy analysis of solid state anaerobic co-digestion of dairy manure with corn stover and tomato residues.

Science.gov (United States)

Li, Yangyang; Xu, Fuqing; Li, Yu; Lu, Jiaxin; Li, Shuyan; Shah, Ajay; Zhang, Xuehua; Zhang, Hongyu; Gong, Xiaoyan; Li, Guoxue

2018-03-01

Anaerobic co-digestion is commonly believed to be benefical for biogas production. However, additional of co-substrates may require additional energy inputs and thus affect the overall energy efficiency of the system. In this study, reactor performance and energy analysis of solid state anaerobic digestion (SS-AD) of tomato residues with dairy manure and corn stover were investigated. Different fractions of tomato residues (0, 20, 40, 60, 80 and 100%, based on volatile solid weight (VS)) were co-digested with dairy manure and corn stover at 15% total solids. Energy analysis based on experimental data was conducted for three scenarios: SS-AD of 100% dairy manure, SS-AD of binary mixture (60% dairy manure and 40% corn stover, VS based), and SS-AD of ternary mixture (36% dairy manure, 24% corn stover, and 40% tomato residues, VS based). For each scenario, the energy requirements for individual process components, including feedstock collection and transportation, feedstock pretreatment, biogas plant operation, digestate processing and handling, and the energy production were examined. Results showed that the addition of 20 and 40% tomato residues increased methane yield compared to that of the dairy manure and corn stover mixture, indicating that the co-digestion could balance nutrients and improve the performance of solid-state anaerobic digestion. The energy required for heating substrates had the dominant effect on the total energy consumption. The highest volatile solids (VS) reduction (57.0%), methane yield (379.1 L/kg VS feed ), and net energy production were achieved with the mixture of 24% corn stover, 36% dairy manure, and 40% tomato residues. Thus, the extra energy input for adding tomato residues for co-digestion could be compensated by the increase of methane yield. Copyright © 2017 Elsevier Ltd. All rights reserved.

X-ray structural studies of quinone reductase 2 nanomolar range inhibitors

Energy Technology Data Exchange (ETDEWEB)

Pegan, Scott D.; Sturdy, Megan; Ferry, Gilles; Delagrange, Philippe; Boutin, Jean A.; Mesecar, Andrew D. (IdRS); (Purdue); (Colorado); (UIC)

2011-09-06

Quinone reductase 2 (QR2) is one of two members comprising the mammalian quinone reductase family of enzymes responsible for performing FAD mediated reductions of quinone substrates. In contrast to quinone reductase 1 (QR1) which uses NAD(P)H as its co-substrate, QR2 utilizes a rare group of hydride donors, N-methyl or N-ribosyl nicotinamide. Several studies have linked QR2 to the generation of quinone free radicals, several neuronal degenerative diseases, and cancer. QR2 has been also identified as the third melatonin receptor (MT3) through in cellulo and in vitro inhibition of QR2 by traditional MT3 ligands, and through recent X-ray structures of human QR2 (hQR2) in complex with melatonin and 2-iodomelatonin. Several MT3 specific ligands have been developed that exhibit both potent in cellulo inhibition of hQR2 nanomolar, affinity for MT3. The potency of these ligands suggest their use as molecular probes for hQR2. However, no definitive correlation between traditionally obtained MT3 ligand affinity and hQR2 inhibition exists limiting our understanding of how these ligands are accommodated in the hQR2 active site. To obtain a clearer relationship between the structures of developed MT3 ligands and their inhibitory properties, in cellulo and in vitro IC{sub 50} values were determined for a representative set of MT3 ligands (MCA-NAT, 2-I-MCANAT, prazosin, S26695, S32797, and S29434). Furthermore, X-ray structures for each of these ligands in complex with hQR2 were determined allowing for a structural evaluation of the binding modes of these ligands in relation to the potency of MT3 ligands.

CD and MCD of CytC3 and taurine dioxygenase: role of the facial triad in alpha-KG-dependent oxygenases.

Science.gov (United States)

Neidig, Michael L; Brown, Christina D; Light, Kenneth M; Fujimori, Danica Galonić; Nolan, Elizabeth M; Price, John C; Barr, Eric W; Bollinger, J Martin; Krebs, Carsten; Walsh, Christopher T; Solomon, Edward I

2007-11-21

The alpha-ketoglutarate (alpha-KG)-dependent oxygenases are a large and diverse class of mononuclear non-heme iron enzymes that require FeII, alpha-KG, and dioxygen for catalysis with the alpha-KG cosubstrate supplying the additional reducing equivalents for oxygen activation. While these systems exhibit a diverse array of reactivities (i.e., hydroxylation, desaturation, ring closure, etc.), they all share a common structural motif at the FeII active site, termed the 2-His-1-carboxylate facial triad. Recently, a new subclass of alpha-KG-dependent oxygenases has been identified that exhibits novel reactivity, the oxidative halogenation of unactivated carbon centers. These enzymes are also structurally unique in that they do not contain the standard facial triad, as a Cl- ligand is coordinated in place of the carboxylate. An FeII methodology involving CD, MCD, and VTVH MCD spectroscopies was applied to CytC3 to elucidate the active-site structural effects of this perturbation of the coordination sphere. A significant decrease in the affinity of FeII for apo-CytC3 was observed, supporting the necessity of the facial triad for iron coordination to form the resting site. In addition, interesting differences observed in the FeII/alpha-KG complex relative to the cognate complex in other alpha-KG-dependent oxygenases indicate the presence of a distorted 6C site with a weak water ligand. Combined with parallel studies of taurine dioxygenase and past studies of clavaminate synthase, these results define a role of the carboxylate ligand of the facial triad in stabilizing water coordination via a H-bonding interaction between the noncoordinating oxygen of the carboxylate and the coordinated water. These studies provide initial insight into the active-site features that favor chlorination by CytC3 over the hydroxylation reactions occurring in related enzymes.

Determining the regional potential for a grass biomethane industry

International Nuclear Information System (INIS)

Smyth, Beatrice M.; Smyth, Henry; Murphy, Jerry D.

2011-01-01

Research highlights: → We identified assessment criteria for determining the regional potential for grass biomethane. → Grass biomethane is distributed via the natural gas grid. → The criteria include: land use; grass yields; gas grid coverage; availability of co-substrates. → The county with the highest potential can fuel 50% of cars or supply 130% of domestic gas consumption. - Abstract: Grass biogas/biomethane has been put forward as a renewable energy solution and it has been shown to perform well in terms of energy balance, greenhouse gas emissions and policy constraints. Biofuel and energy crop solutions are country-specific and grass biomethane has strong potential in countries with temperate climates and a high proportion of grassland, such as Ireland. For a grass biomethane industry to develop in a country, suitable regions (i.e. those with the highest potential) must be identified. In this paper, factors specifically related to the assessment of the potential of a grass biogas/biomethane industry are identified and analysed. The potential for grass biogas and grass biomethane is determined on a county-by-county basis using multi-criteria decision analysis. Values are assigned to each county and ratings and weightings applied to determine the overall county potential. The potential for grass biomethane with co-digestion of slaughter waste (belly grass) is also determined. The county with the highest potential (Limerick) is analysed in detail and is shown to have ready potential for production of gaseous biofuel to meet either 50% of the vehicle fleet or 130% of the domestic natural gas demand, through 25 facilities at a scale of ca. 30 kt yr -1 of feedstock. The assessment factors developed in this paper can be used in other resource studies into grass biomethane or other energy crops.

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria

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Xuezhu Zhu

2016-08-01

Full Text Available Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P1 (Stenotrophomonas sp. and P3 (Pseudomonas sp., which degraded more than 90% of phenanthrene (PHE within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP, PHE, fluorene (FLR, pyrene (PYR, and benzo(apyrene (B(aP as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P1 degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(aP, and strain P3 degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(aP. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days. Compared with strain P1, strain P3 has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

Plant exudates promote PCB degradation by a rhodococcal rhizobacteria

Energy Technology Data Exchange (ETDEWEB)

Toussaint, Jean-Patrick; Pham, Thi Thanh My; Barriault, Diane; Sylvestre, Michel [Instiut National de la Recherche Scientifique INRS, Laval, QC (Canada). Inst. Armand-Frappier

2012-09-15

Rhodococcus erythropolis U23A is a polychlorinated biphenyl (PCB)-degrading bacterium isolated from the rhizosphere of plants grown on a PCB-contaminated soil. Strain U23A bphA exhibited 99% identity with bphA1 of Rhodococcus globerulus P6. We grew Arabidopsis thaliana in a hydroponic axenic system, collected, and concentrated the plant secondary metabolite-containing root exudates. Strain U23A exhibited a chemotactic response toward these root exudates. In a root colonizing assay, the number of cells of strain U23A associated to the plant roots (5.7 x 105 CFU g{sup -1}) was greater than the number remaining in the surrounding sand (4.5 x 104 CFU g{sup -1}). Furthermore, the exudates could support the growth of strain U23A. In a resting cell suspension assay, cells grown in a minimal medium containing Arabidopsis root exudates as sole growth substrate were able to metabolize 2,3,4'- and 2,3',4-trichlorobiphenyl. However, no significant degradation of any of congeners was observed for control cells grown on Luria-Bertani medium. Although strain U23A was unable to grow on any of the flavonoids identified in root exudates, biphenyl-induced cells metabolized flavanone, one of the major root exudate components. In addition, when used as co-substrate with sodium acetate, flavanone was as efficient as biphenyl to induce the biphenyl catabolic pathway of strain U23A. Together, these data provide supporting evidence that some rhodococci can live in soil in close association with plant roots and that root exudates can support their growth and trigger their PCB-degrading ability. This suggests that, like the flagellated Gram-negative bacteria, non-flagellated rhodococci may also play a key role in the degradation of persistent pollutants. (orig.)

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)

An artificial TCA cycle selects for efficient α-ketoglutarate dependent hydroxylase catalysis in engineered Escherichia coli.

Science.gov (United States)

Theodosiou, Eleni; Breisch, Marina; Julsing, Mattijs K; Falcioni, Francesco; Bühler, Bruno; Schmid, Andreas

2017-07-01

Amino acid hydroxylases depend directly on the cellular TCA cycle via their cosubstrate α-ketoglutarate (α-KG) and are highly useful for the selective biocatalytic oxyfunctionalization of amino acids. This study evaluates TCA cycle engineering strategies to force and increase α-KG flux through proline-4-hydroxylase (P4H). The genes sucA (α-KG dehydrogenase E1 subunit) and sucC (succinyl-CoA synthetase β subunit) were alternately deleted together with aceA (isocitrate lyase) in proline degradation-deficient Escherichia coli strains (ΔputA) expressing the p4h gene. Whereas, the ΔsucCΔaceAΔputA strain grew in minimal medium in the absence of P4H, relying on the activity of fumarate reductase, growth of the ΔsucAΔaceAΔputA strictly depended on P4H activity, thus coupling growth to proline hydroxylation. P4H restored growth, even when proline was not externally added. However, the reduced succinyl-CoA pool caused a 27% decrease of the average cell size compared to the wildtype strain. Medium supplementation partially restored the morphology and, in some cases, enhanced proline hydroxylation activity. The specific proline hydroxylation rate doubled when putP, encoding the Na + /l-proline transporter, was overexpressed in the ΔsucAΔaceAΔputA strain. This is in contrast to wildtype and ΔputA single-knock out strains, in which α-KG availability obviously limited proline hydroxylation. Such α-KG limitation was relieved in the ΔsucAΔaceAΔputA strain. Furthermore, the ΔsucAΔaceAΔputA strain was used to demonstrate an agar plate-based method for the identification and selection of active α-KG dependent hydroxylases. This together with the possibility to waive selection pressure and overcome α-KG limitation in respective hydroxylation processes based on living cells emphasizes the potential of TCA cycle engineering for the productive application of α-KG dependent hydroxylases. Biotechnol. Bioeng. 2017;114: 1511-1520. © 2017 Wiley Periodicals, Inc. �

Scavenging of free-radical metabolites of aniline xenobiotics and drugs by amino acid derivatives: toxicological implications of radical-transfer reactions.

Science.gov (United States)

Michail, Karim; Baghdasarian, Argishti; Narwaley, Malyaj; Aljuhani, Naif; Siraki, Arno G

2013-12-16

We investigated a novel scavenging mechanism of arylamine free radicals by poly- and monoaminocarboxylates. Free radicals of arylamine xenobiotics and drugs did not react with oxygen in peroxidase-catalyzed reactions; however, they showed marked oxygen uptake in the presence of an aminocarboxylate. These free-radical intermediates were identified using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and electron paramagnetic resonance (EPR) spectrometry. Diethylenetriaminepentaacetic acid (DTPA), a polyaminocarboxylate, caused a concentration-dependent attenuation of N-centered radicals produced by the peroxidative metabolism of arylamines with the subsequent formation of secondary aliphatic carbon-centered radicals stemming from the cosubstrate molecule. Analogously, N,N-dimethylglycine (DMG) and N-methyliminodiacetate (MIDA), but not iminodiacetic acid (IDA), demonstrated a similar scavenging effect of arylamine-derived free radicals in a horseradish peroxidase/H2O2 system. Using human promyelocytic leukemia (HL-60) cell lysate as a model of human neutrophils, DTPA, MIDA, and DMG readily reduced anilinium cation radicals derived from the arylamines and gave rise to the corresponding carbon radicals. The rate of peroxidase-triggered polymerization of aniline was studied as a measure of nitrogen-radical scavenging. Although, IDA had no effect on the rate of aniline polymerization, this was almost nullified in the presence of DTPA and MIDA at half of the molar concentration of the aniline substrate, whereas a 20 molar excess of DMPO caused only a partial inhibition. Furthermore, the yield of formaldehyde, a specific reaction endproduct of the oxidation of aminocarboxylates by aniline free-radical metabolites, was quantitatively determined. Azobenzene, a specific reaction product of peroxidase-catalyzed free-radical dimerization of aniline, was fully abrogated in the presence of DTPA, as confirmed by GC/MS. Under aerobic conditions, a radical-transfer reaction

Regulation of NAD+ metabolism, signaling and compartmentalization in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Kato, Michiko; Lin, Su-Ju

2014-11-01

Pyridine nucleotides are essential coenzymes in many cellular redox reactions in all living systems. In addition to functioning as a redox carrier, NAD(+) is also a required co-substrate for the conserved sirtuin deacetylases. Sirtuins regulate transcription, genome maintenance and metabolism and function as molecular links between cells and their environment. Maintaining NAD(+) homeostasis is essential for proper cellular function and aberrant NAD(+) metabolism has been implicated in a number of metabolic- and age-associated diseases. Recently, NAD(+) metabolism has been linked to the phosphate-responsive signaling pathway (PHO pathway) in the budding yeast Saccharomyces cerevisiae. Activation of the PHO pathway is associated with the production and mobilization of the NAD(+) metabolite nicotinamide riboside (NR), which is mediated in part by PHO-regulated nucleotidases. Cross-regulation between NAD(+) metabolism and the PHO pathway has also been reported; however, detailed mechanisms remain to be elucidated. The PHO pathway also appears to modulate the activities of common downstream effectors of multiple nutrient-sensing pathways (Ras-PKA, TOR, Sch9/AKT). These signaling pathways were suggested to play a role in calorie restriction-mediated beneficial effects, which have also been linked to Sir2 function and NAD(+) metabolism. Here, we discuss the interactions of these pathways and their potential roles in regulating NAD(+) metabolism. In eukaryotic cells, intracellular compartmentalization facilitates the regulation of enzymatic functions and also concentrates or sequesters specific metabolites. Various NAD(+)-mediated cellular functions such as mitochondrial oxidative phosphorylation are compartmentalized. Therefore, we also discuss several key players functioning in mitochondrial, cytosolic and vacuolar compartmentalization of NAD(+) intermediates, and their potential roles in NAD(+) homeostasis. To date, it remains unclear how NAD(+) and NAD(+) intermediates

In Silico understanding of the cyclodextrin–phenanthrene hybrid assemblies in both aqueous medium and bacterial membranes

Energy Technology Data Exchange (ETDEWEB)

Ren, Baiping [College of Life Science and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024 (China); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Gao, Huipeng; Cao, Yafeng [College of Life Science and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024 (China); Jia, Lingyun, E-mail: lyj81@dlut.edu.cn [College of Life Science and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116024 (China)

2015-03-21

Highlights: • Two hetero-assemblies, βCD{sub 1}–Phe{sub 1}, and βCD{sub 2}–Phe{sub 1} were observed in water solution. • Distinct membrane-binding patterns for βCD, Phe, and their complexes were found. • Minor Phe trans-membrane energy barrier confirmed its membrane penetration ability. • Huge energy barriers for βCD-involved assemblies denied their membrane penetration. • Phe separation from βCD{sub 1}–Phe{sub 1} was easier than that from βCD{sub 2}–Phe{sub 1}. - Abstract: The explicit-solvent molecular dynamic (MD) simulation and adaptive biased forces (ABF) methods were employed to systemically study the structural and thermodynamic nature of the β-cyclodextrin (βCD) monomer, phenanthrene (Phe) monomer, and their inclusion complexes in both the aqueous and membrane environments, aiming at clarifying the atomic-level mechanisms underlying in the CD-enhanced degradation of polycyclic aromatic hydrocarbons (PAHs) by bacteria. Simulations showed that βCD and Phe monomers could associate together to construct two distinctive assemblies, i.e, βCD{sub 1}–Phe{sub 1} and βCD{sub 2}–Phe{sub 1}, respectively. The membrane-involved equilibrium simulations and the data of potential of mean forces (PMFs) further confirmed that Phe monomer was capable of penetrating through the membranes without confronting any large energy barrier, whereas, the single βCD and βCD-involved assemblies were unable to pass across the membranes. These observations clearly suggested that βCD only served as the carrier to enhance the bioavailability of Phe rather than the co-substrate in the Phe biodegradation process. The Phe-separation PMF profiles indicated that the maximum of the Phe uptake by bacteria would be achieved by the “optimal” βCD:Phe molar ratio, which facilitated the maximal formation of βCD{sub 1}–Phe{sub 1} inclusion and the minimal construction of βCD{sub 2}–Phe{sub 1} complex.

Deregulation of S-adenosylmethionine biosynthesis and regeneration improves methylation in the E. coli de novo vanillin biosynthesis pathway.

Science.gov (United States)

Kunjapur, Aditya M; Hyun, Jason C; Prather, Kristala L J

2016-04-11

Vanillin is an industrially valuable molecule that can be produced from simple carbon sources in engineered microorganisms such as Saccharomyces cerevisiae and Escherichia coli. In E. coli, de novo production of vanillin was demonstrated previously as a proof of concept. In this study, a series of data-driven experiments were performed in order to better understand limitations associated with biosynthesis of vanillate, which is the immediate precursor to vanillin. Time-course experiments monitoring production of heterologous metabolites in the E. coli de novo vanillin pathway revealed a bottleneck in conversion of protocatechuate to vanillate. Perturbations in central metabolism intended to increase flux into the heterologous pathway increased average vanillate titers from 132 to 205 mg/L, but protocatechuate remained the dominant heterologous product on a molar basis. SDS-PAGE, in vitro activity measurements, and L-methionine supplementation experiments suggested that the decline in conversion rate was influenced more by limited availability of the co-substrate S-adenosyl-L-methionine (AdoMet or SAM) than by loss of activity of the heterologous O-methyltransferase. The combination of metJ deletion and overexpression of feedback-resistant variants of metA and cysE, which encode enzymes involved in SAM biosynthesis, increased average de novo vanillate titers by an additional 33% (from 205 to 272 mg/L). An orthogonal strategy intended to improve SAM regeneration through overexpression of native mtn and luxS genes resulted in a 25% increase in average de novo vanillate titers (from 205 to 256 mg/L). Vanillate production improved further upon supplementation with methionine (as high as 419 ± 58 mg/L), suggesting potential for additional enhancement by increasing SAM availability. Results from this study demonstrate context dependency of engineered pathways and highlight the limited methylation capacity of E. coli. Unlike in previous efforts to improve SAM or

Kinetic mechanism of Toxoplasma gondii adenosine kinase and the highly efficient utilization of adenosine

Science.gov (United States)

Naguib, Fardos N. M.; Rais, Reem H.; Al Safarjalani, Omar N.; el Kouni, Mahmoud H.

2015-01-01

Toxoplasma gondii has an extraordinarily ability to utilize adenosine (Ado) as the primary source of all necessary purines in this parasite which lacks de novo purine biosynthesis. The activity of T. gondii adenosine kinase (TgAK, EC 2.7.1.20) is responsible for this efficient salvage of Ado in T. gondii. To fully understand this remarkable efficiency of TgAK in the utilization of Ado, complete kinetic parameters of this enzyme are necessary. Initial velocity and product inhibition studies of TgAK demonstrated that the basic mechanism of this enzyme is a hybrid random bi-uni ping-pong uni-bi. Initial velocity studies showed an intersecting pattern, consistent with substrate-enzyme-co-substrate complex formation and a binding pattern indicating that binding of the substrate interferes with the binding of the co-substrate and vice versa. Estimated kinetic parameters were KAdo = 0.002 ± 0.0002 mM, KATP = 0.05 ± 0.008 mM, and Vmax = 920 ± 35 μmol/min/mg protein. Ado exhibited substrate inhibition suggesting the presence of more than one binding site for Ado on the enzyme. ATP relieved substrate inhibition by Ado. Thus, Ado also binds to the ATP binding site. AMP was competitive with ATP, inferring that AMP binds to the same site as ATP. AMP, ADP and ATP were non-competitive with Ado, therefore, none of these nucleotides binds to the Ado binding site. Combining ATP with ADP was additive. Therefore, the binding of either ATP or ADP does not interfere with the binding of the other. It is concluded that for every ATP consumed, TgAK generates three new AMPs. These findings along with the fact that a wide range of nucleoside 5′-mono, di, and triphosphates could substitute for ATP as phosphate donors in this reaction may explain the efficient and central role played by TgAK in the utilization of Ado as the major source from which all other purines can be synthesized in T. gondii. PMID:26112826

Modulation of sulfur metabolism enables efficient glucosinolate engineering

Directory of Open Access Journals (Sweden)

Geu-Flores Fernando

2011-01-01

heterologous hosts. Our study emphasizes the importance of considering co-substrates and their biological nature in metabolic engineering projects.

Biocatalytic anti-Prelog reduction of prochiral ketones with whole cells of Acetobacter pasteurianus GIM1.158.

Science.gov (United States)

Du, Peng-Xuan; Wei, Ping; Lou, Wen-Yong; Zong, Min-Hua

2014-06-10

Enantiomerically pure alcohols are important building blocks for production of chiral pharmaceuticals, flavors, agrochemicals and functional materials and appropriate whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to these valuable compounds. At present, most of these biocatalysts follow Prelog's rule, and thus the (S)-alcohols are usually obtained when the smaller substituent of the ketone has the lower CIP priority. Only a few anti-Prelog (R)-specific whole cell biocatalysts have been reported. In this paper, the biocatalytic anti-Prelog reduction of 2-octanone to (R)-2-octanol was successfully conducted with high enantioselectivity using whole cells of Acetobacter pasteurianus GIM1.158. Compared with other microorganisms investigated, Acetobacter pasteurianus GIM1.158 was shown to be more effective for the reduction reaction, affording much higher yield, product enantiomeric excess (e.e.) and initial reaction rate. The optimal temperature, buffer pH, co-substrate and its concentration, substrate concentration, cell concentration and shaking rate were 35°C, 5.0, 500 mmol/L isopropanol, 40 mmol/L, 25 mg/mL and 120 r/min, respectively. Under the optimized conditions, the maximum yield and the product e.e. were 89.5% and >99.9%, respectively, in 70 minutes. Compared with the best available data in aqueous system (yield of 55%), the yield of (R)-2-octanol was greatly increased. Additionally, the efficient whole-cell biocatalytic process was feasible on a 200-mL preparative scale and the chemical yield increased to 95.0% with the product e.e. being >99.9%. Moreover, Acetobacter pasteurianus GIM1.158 cells were proved to be capable of catalyzing the anti-Prelog bioreduction of other prochiral carbonyl compounds with high efficiency. Via an effective increase in the maximum yield and the product e.e. with Acetobacter pasteurianus GIM1.158 cells, these results open the way to use of whole cells of this microorganism for

Insights into phosphate cooperativity and influence of substrate modifications on binding and catalysis of hexameric purine nucleoside phosphorylases.

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Priscila O de Giuseppe

Full Text Available The hexameric purine nucleoside phosphorylase from Bacillus subtilis (BsPNP233 displays great potential to produce nucleoside analogues in industry and can be exploited in the development of new anti-tumor gene therapies. In order to provide structural basis for enzyme and substrates rational optimization, aiming at those applications, the present work shows a thorough and detailed structural description of the binding mode of substrates and nucleoside analogues to the active site of the hexameric BsPNP233. Here we report the crystal structure of BsPNP233 in the apo form and in complex with 11 ligands, including clinically relevant compounds. The crystal structure of six ligands (adenine, 2'deoxyguanosine, aciclovir, ganciclovir, 8-bromoguanosine, 6-chloroguanosine in complex with a hexameric PNP are presented for the first time. Our data showed that free bases adopt alternative conformations in the BsPNP233 active site and indicated that binding of the co-substrate (2'deoxyribose 1-phosphate might contribute for stabilizing the bases in a favorable orientation for catalysis. The BsPNP233-adenosine complex revealed that a hydrogen bond between the 5' hydroxyl group of adenosine and Arg(43* side chain contributes for the ribosyl radical to adopt an unusual C3'-endo conformation. The structures with 6-chloroguanosine and 8-bromoguanosine pointed out that the Cl(6 and Br(8 substrate modifications seem to be detrimental for catalysis and can be explored in the design of inhibitors for hexameric PNPs from pathogens. Our data also corroborated the competitive inhibition mechanism of hexameric PNPs by tubercidin and suggested that the acyclic nucleoside ganciclovir is a better inhibitor for hexameric PNPs than aciclovir. Furthermore, comparative structural analyses indicated that the replacement of Ser(90 by a threonine in the B. cereus hexameric adenosine phosphorylase (Thr(91 is responsible for the lack of negative cooperativity of phosphate binding

Prolyl hydroxylase domain enzymes: important regulators of cancer metabolism

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Yang M

2014-08-01

Full Text Available Ming Yang,1 Huizhong Su,1 Tomoyoshi Soga,2 Kamil R Kranc,3 Patrick J Pollard1 1Cancer Biology and Metabolism Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK; 2Institute for Advanced Biosciences, Keio University, Mizukami, Tsuruoka, Yamagata, Japan; 3MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK Abstract: The hypoxia-inducible factor (HIF prolyl hydroxylase domain enzymes (PHDs regulate the stability of HIF protein by post-translational hydroxylation of two conserved prolyl residues in its α subunit in an oxygen-dependent manner. Trans-4-prolyl hydroxylation of HIFα under normal oxygen (O2 availability enables its association with the von Hippel-Lindau (VHL tumor suppressor pVHL E3 ligase complex, leading to the degradation of HIFα via the ubiquitin-proteasome pathway. Due to the obligatory requirement of molecular O2 as a co-substrate, the activity of PHDs is inhibited under hypoxic conditions, resulting in stabilized HIFα, which dimerizes with HIFβ and, together with transcriptional co-activators CBP/p300, activates the transcription of its target genes. As a key molecular regulator of adaptive response to hypoxia, HIF plays important roles in multiple cellular processes and its overexpression has been detected in various cancers. The HIF1α isoform in particular has a strong impact on cellular metabolism, most notably by promoting anaerobic, whilst inhibiting O2-dependent, metabolism of glucose. The PHD enzymes also seem to have HIF-independent functions and are subject to regulation by factors other than O2, such as by metabolic status, oxidative stress, and abnormal levels of endogenous metabolites (oncometabolites that have been observed in some types of cancers. In this review, we aim to summarize current understandings of the function and regulation of PHDs in cancer with an emphasis on their roles in metabolism. Keywords: prolyl hydroxylase domain (PHD

Synthesis and antioxidant activity of peptide-based ebselen analogues.

Science.gov (United States)

Satheeshkumar, Kandhan; Mugesh, Govindasamy

2011-04-18

A series of di- and tripeptide-based ebselen analogues has been synthesized. The compounds were characterized by (1)H, (13)C, and (77)Se NMR spectroscopy and mass spectral techniques. The glutathione peroxidase (GPx)-like antioxidant activity has been studied by using H(2)O(2) , tert-butyl hydroperoxide (tBuOOH), and cumene hydroperoxide (Cum-OOH) as substrates, and glutathione (GSH) as a cosubstrate. Although all the peptide-based compounds have a selenazole ring similar to that of ebselen, the GPx activity of these compounds highly depends on the nature of the peptide moiety attached to the nitrogen atom of the selenazole ring. It was observed that the introduction of a phenylalanine (Phe) amino acid residue in the N-terminal reduces the activity in all three peroxide systems. On the other hand, the introduction of aliphatic amino acid residues such as valine (Val) significantly enhances the GPx activity of the ebselen analogues. The difference in the catalytic activity of dipeptide-based ebselen derivatives can be ascribed mainly to the change in the reactivity of these compounds toward GSH and peroxide. Although the presence of the Val-Ala-CO(2) Me moiety facilitates the formation of a catalytically active selenol species, the reaction of ebselen analogues that has a Phe-Ile-CO(2) Me residue with GSH does not generate the corresponding selenol. To understand the antioxidant activity of the peptide-based ebselen analogues in the absence of GSH, these compounds were studied for their ability to inhibit peroxynitrite (PN)-mediated nitration of bovine serum albumin (BSA) and oxidation of dihydrorhodamine 123. In contrast to the GPx activity, the PN-scavenging activity of the Phe-based peptide analogues was found to be comparable to that of the Val-based compounds. However, the introduction of an additional Phe residue to the ebselen analogue that had a Val-Ala dipeptide significantly reduced the potency of the parent compound in PN-mediated nitration. Copyright �

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.)

Atividade peroxidásica em basófilos de Phrynops geoffroanus (Testudines Chelidae Peroxidase activity in the basophils of Phrynops geoffroanus (Testudines: Chelidae

Directory of Open Access Journals (Sweden)

Maria Isabel Afonso da Silva

2010-01-01

Full Text Available As peroxidases, presentes nos peroxissomos e lisossomos, pertencem às oxidases e atuam como catalítico para o peróxido de hidrogênio (H2O2, posteriormente decomposto pela oxidação de cossubstratos, evitando danos celulares.(¹ Foi aplicada a técnica da peroxidase(2 em esfregaços sanguíneos de Phrynops geoffroanus, comparando com sangue humano, para avaliação da atividade e controle da reação. O esfregaço sanguíneo humano apresentou marcações em neutrófilos, fagócitos com muitos lisossomos e peroxissomos (Figura 1. Nos esfregaços sanguíneos de Phrynops geoffroanus, as marcações apresentaram-se nos basófilos (Figura 2, que representam de 10% a 25% dos leucócitos de quelônios e possuem grande número de granulações citoplasmáticas,(3 sugerindo a presença de grande quantidade de enzimas e organelas como lisossomos e peroxissomos, possivelmente associadas a sua participação em reações imunes. A atividade peroxidásica representa resposta do organismo a ações ambientais danosas, servindo como marcador biológico.Peroxidase, present in peroxisomes and lysosomes, belongs to the oxidases and acts as a catalyst for hydrogen peroxide (H2O2 and is later decomposed by oxidation of cosubstrates thereby preventing cell damage.(1 The peroxidase technique(2 was applied to blood smears of Phrynops geoffroanus and the results compared with human blood to evaluate the activity and control of the reaction. The human blood film showed markings in neutrophils and phagocytes with many lysosomes and peroxisomes (Figure 1. In blood smears of Phrynops geoffroanus, the markings were on the basophils (Figure 2, that represent 10% to 25% of leukocytes of turtles and have a large number of cytoplasmatic granules(3 suggesting the presence of large amounts of enzymes and organelles such as lysosomes and peroxisomes, possibly associated with their participation in immune reactions. Peroxidase activity is the body's response to harmful

The MAO-A inhibitor clorgyline reduces ethanol-induced locomotion and its volitional intake in mice.

Science.gov (United States)

Ledesma, Juan Carlos; Escrig, Miguel Angel; Pastor, Raúl; Aragon, Carlos M G

2014-01-01

Hydrogen peroxide is the co-substrate used by the enzyme catalase to form Compound I (the catalase-H2O2 system), which is the major pathway for the conversion of ethanol (EtOH) into acetaldehyde in the brain. This acetaldehyde has been involved in many of the effects of EtOH. Previous research demonstrated that treatments that change the levels of cerebral H2O2 available to catalase modulate the locomotor-stimulating effects of EtOH and its volitional intake in rodents. However, the source of H2O2 which is used by catalase to form Compound I and mediates the psychoactive actions of EtOH is unknown. One cause of the generation of H2O2 in the brain comes from the deamination of biogenic amines by the activity of MAO-A. Here we explore the consequences of the administration of the MAO-A inhibitor clorgyline on EtOH-induced locomotion and voluntary EtOH drinking. For the locomotor activity tests, we injected Swiss (RjOrl) mice intraperitoneally (IP) with clorgyline (0-10mg/kg) and later (0.5-8h) with EtOH (0-3.75 g/kg; IP). Following these treatments, mice were placed in locomotor activity chambers to measure their locomotion. For the drinking experiments, mice of the C57BL/6J strain were injected IP with clorgyline prior to offering them an EtOH (20%) solution following a drinking-in-the-dark procedure. Additional experiments were performed to assess the selectivity of this compound in altering EtOH-stimulated locomotion and EtOH intake. Moreover, we indirectly tested the ability of clorgyline to reduce brain H2O2 levels. We showed that this treatment selectively reduced EtOH-induced locomotion and its self-administration. Moreover, this compound decreased central H2O2 levels available to catalase. We suggest that H2O2 derived from the deamination of biogenic amines by the activity of MAO-A could determine the formation of brain EtOH-derived acetaldehyde. This centrally-formed acetaldehyde within the neurons of the aminergic system could play a role in the

Development of a method for influencing the nutrient content ofs stabilised sewage sludge by further treatment. Final report; Entwicklung eines Verfahrens zur Beeinflussung der Naehrstoffgehalte bei der weitergehenden Behandlung von stabilisierten Klaerschlaemmen. Verfahren der Aerob-Anoxischen Nachbehandlung - AAN-Verfahren. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Voigtlaender, G.; Lopp, M.

2002-11-01

-N-Rueckbelastungen in die KA um etwa 70% reduziert, waehrend sich die N-Frachten im entwaesserten Klaerschlamm um etwa 45% vermindern. Die Trockensubstanzgehalte im Klaerschlamm werden durch weiteren Abbau organischer Verbindungen um 20...25% reduziert. Dies kommt einer aequivalenten Mengenreduzierung des entwaesserten Klaerschlammes gleich. Die Entwaesserungseigenschaften des Schlammes werden deutlich verbessert. Vor allem die erhoehte Trennschaerfe und somit die verbesserte Schlammwasserqualitaet bedeutet im praktischen Einsatz eine Einsparung an Betriebskosten fuer Chemikalien (z.B. Polyelektrolyt). Tests in der Kammerfilterpresse und Flockungstest zeigten ebenfalls verbesserte Entwaesserungseigenschaften. Weiterhin ist festzustellen: Die Moeglichkeit der Faulzeitverkuerzung (ca. 15 d) bringt weitere Einsparpotentiale im Bereich der Schlammfaulung. Die zusaetzliche Rueckbelastungsreduzierung in Bezug auf P und schwer abbaubaren CSB entlastet die KA. Die Kombination mit der Klaerschlammdesintegration kommt vor allem bei sehr kurzen Faulzeiten (ca. 10 d) zum Tragen. Die Erprobung des Verfahrens fuer simultan aerob stabilisierte Schlaemme fuehrte, auch in Kombination mit der Klaerschlammdesintegration, nur zu Stickstoffreduzierungen von bis zu 15% und blieb damit unter den Erwartungen. Insgesamt laesst sich feststellen, dass das Projekt inhaltlich erfolgreich abgeschlossen wurde, dass die Ergebnisse in Bezug auf die Hauptzielrichtungen ausserordentlich positiv ausfielen und das der vorgesehene Kostenrahmen eingehalten wurde. Die Reduzierung der Stickstoffgehalte wird in absehbarer Zeit vorrangig der landschaftsbaulichen Verwertung zugute kommen. Insbesondere die Kombination der genannten Effekte macht das Verfahren fuer die praktische Anwendung interessant. (orig.)

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.

Enhancement of biogas production from sewage sludge by addition of grease trap sludge

International Nuclear Information System (INIS)

Grosser, A.; Neczaj, E.

2016-01-01

one factor ANOVA. While the long chain fatty acids reduction is not correlated with the gradual increase of fat rich material in the feedstock. The results of the present laboratory study revealed the use of grease trap sludge as a co-substrate is an interesting method for intensification of methane production from sewage sludge.

Optimizing Polychlorinated Biphenyl Degradation by Flavonoid-Induced Cells of the Rhizobacterium Rhodococcus erythropolis U23A.

Directory of Open Access Journals (Sweden)

Thi Thanh My Pham

Full Text Available There is evidence that many plant secondary metabolites may act as signal molecules to trigger the bacterial ability to metabolize polychlorinated biphenyls (PCBs during the rhizoremediation process. However, the bases for the PCB rhizoremediation process are still largely unknown. The rhizobacterium Rhodococcus erythropolis U23A is unable to use flavanone as a growth substrate. However, on the basis of an assay that monitors the amount of 4-chlorobenzoate produced from 4-chlorobiphenyl by cells grown co-metabolically on flavanone plus sodium acetate, this flavonoid was previously found to be a potential inducer of the U23A biphenyl catabolic pathway. In this work, and using the same assay, we identified ten other flavonoids that did not support growth, but that acted as inducers of the U23A biphenyl pathway, and we confirmed flavonoid induction of the biphenyl catabolic pathway using quantitative real-time polymerase chain reaction (RT-qPCR on the bphA gene. We also examined the effect of the growth co-substrate on flavonoid induction. Sodium acetate was replaced by glucose, mannose, sucrose, or mannitol, which are sugars found in plant root exudates. The data showed that the level of induction of strain U23A biphenyl-degrading enzymes was significantly influenced by the nature and concentration of the flavonoid in the growth medium, as well as by the substrate used for growth. Sucrose allowed for an optimal induction response for most flavonoids. Some flavonoids, such as flavone and isoflavone, were better inducers of the biphenyl catabolic enzymes than biphenyl itself. We also found that all flavonoids tested in this work were metabolized by strain U23A during co-metabolic growth, but that the metabolite profiles, as well as the level of efficiency of degradation, differed for each flavonoid. To obtain insight into how flavonoids interact with strain U23A to promote polychlorinated biphenyl (PCB degradation, we determined the concentration of

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.)

Continuously-stirred anaerobic digester to convert organic wastes into biogas: system setup and basic operation.

Science.gov (United States)

Usack, Joseph G; Spirito, Catherine M; Angenent, Largus T

2012-07-13

Anaerobic digestion (AD) is a bioprocess that is commonly used to convert complex organic wastes into a useful biogas with methane as the energy carrier. Increasingly, AD is being used in industrial, agricultural, and municipal waste(water) treatment applications. The use of AD technology allows plant operators to reduce waste disposal costs and offset energy utility expenses. In addition to treating organic wastes, energy crops are being converted into the energy carrier methane. As the application of AD technology broadens for the treatment of new substrates and co-substrate mixtures, so does the demand for a reliable testing methodology at the pilot- and laboratory-scale. Anaerobic digestion systems have a variety of configurations, including the continuously stirred tank reactor (CSTR), plug flow (PF), and anaerobic sequencing batch reactor (ASBR) configurations. The CSTR is frequently used in research due to its simplicity in design and operation, but also for its advantages in experimentation. Compared to other configurations, the CSTR provides greater uniformity of system parameters, such as temperature, mixing, chemical concentration, and substrate concentration. Ultimately, when designing a full-scale reactor, the optimum reactor configuration will depend on the character of a given substrate among many other nontechnical considerations. However, all configurations share fundamental design features and operating parameters that render the CSTR appropriate for most preliminary assessments. If researchers and engineers use an influent stream with relatively high concentrations of solids, then lab-scale bioreactor configurations cannot be fed continuously due to plugging problems of lab-scale pumps with solids or settling of solids in tubing. For that scenario with continuous mixing requirements, lab-scale bioreactors are fed periodically and we refer to such configurations as continuously stirred anaerobic digesters (CSADs). This article presents a general

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.)

Swift heavy ion induced modification of aliphatic polymers

Energy Technology Data Exchange (ETDEWEB)

Hossain, Umme Habiba

2015-01-15

species. While the irradiation of polymers with high energy heavy ions represents a enforced simulation test of the radiation damage in accelerators, they correspond to real situation in space where devices are directly being hit by very high energy heavy ions. [German] In dieser Arbeit wird die Veraenderung aliphatischer Polymere durch hochenergetische Schwerionenbestrahlung untersucht. Zwei Polymergruppen, naemlich Polyvinyl-Polymere (PVF, PVAc, PVA und PMMA) und Fluor-Polymere (PVDF, ETFE, PFA und FEP) wurden betrachtet. Polyvinyl-Polymere werden als Isolationsmaterial in supraleitenden Magneten der geplanten internationalen Beschleuniger-Anlage Forschung mit Antiprotonen und Ionen (FAIR) an der GSI Helmholzzentrum fuer Scherionenforschung Verwendung finden. Um die ioneninduzierten Aenderungen zu studieren, wurden alle Polymerfolien am Linearbeschleuniger UNILAC an der GSI bestrahlt. Um die Degradation untersuchen zu koennen, wurden verschiedene Ionensorten (U, Au, Sm, Xe), Experimentierstaende (Strahlzweige X0 und M3) und ein weiter Ionen-Fluenz-Bereich (1 x 10{sup 10} - 5 x 10{sup 12} Ionen/cm{sup 2}) Ionen/cm2 genutzt. Fuenf unabhaengige Techniken, Infrarot (FTIR) - und (UV-Vis) Spektroskopie, Restgasanalyse (RGA), Thermogravimetrie (TGA) und Massenverlustanalyse (ML), dienten zur Untersuchung der Materialveraenderungen. Durch die FT-IR-Spektroskopie konnte nachgewiesen werden, dass die Ionenbestrahlung zu einem Rueckgang der charakteristischen Banden fuehrt, die durch Abbau der Polymere hervorgerufen wird, mit Abspaltung der Seitenketten und Bruch des Polymerrueckgrats. Als Konsequenz der strukturellen Aenderung erschienen neue Banden. UV-Vis Absorptionsspektrometrie zeigt eine Verschiebung der Absorptionskante vom ultravioletten Spektralbereich ins Sichtbare, welcher auf die Entstehung von Doppelbindungen und konjugierten Doppelbindungen hinweist. On-line Restgasanalyse zeigt, dass als Fragmente kleine Gasmolekuele freigesetzt werden. TGA weist auf veraenderte

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

Effect of dilution and L-malic acid addition on bio-hydrogen production with Rhodopseudomonas palustris from effluent of an acidogenic anaerobic reactor

International Nuclear Information System (INIS)

Azbar, N.; Tuba, F.; Dokgoz, C.

2009-01-01

production reactor was not suitable for photo-fermentative hydrogen production. 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. The second conclusion that can be drawn is that cheese whey effluent should be mixed with L-malic acid rich co-substrates such as fruit juice processing effluents before fed into the photo-fermentation reactor. Finally, the two-stage H 2 -producing process could be applied in remediation of lactose-containing industrial wastes, H 2 being used on-site, to reduce process costs via generation of electricity by the help of hydrogen fuel cells. (author)

Conversion of hemicellulose and D-xylose into ethanol by the use of thermophilic anaerobic bacteria

Energy Technology Data Exchange (ETDEWEB)

Sommer, Peter

1998-02-01

were improved on this substrate. The growth medium for fermentation of thermophilic anaerobic bacteria is complex and therefore uneconomical on an industrial scale. It contains e.g. growth factors, like vitamins and trace elements, and co-substrates such as yeast extract. The effect of vitamin and trace element addition on viability and ethanol production was examined. It was concluded that only half of these growth factors were needed in the medium for production of ethanol. Physiological studies of thermophilic anaerobic bacteria have shown that the ethanol yield decreases at increasing substrate concentration. The biochemical limitations causing this phenomenon are not known in detail. Physiological and biochemical studies of T. mathranii, including extraction of intracellular metabolites and enzymes of the pentose phosphate pathway and glycolysis, revealed several bottlenecks in the D-xylose metabolism. This knowledge makes way for physiologicl and genetic engineering of this strain to improve the ethanol yield and productivity at high concentration of D-xylose. (au) EFP-94. 164 refs.

Conversion of sewage treatment plants on sludge digestion. Energetic and economic optimization potential; Umstellung von Klaeranlagen auf Schlammfaulung. Energetisches und oekonomisches Optimierungspotenzial

Energy Technology Data Exchange (ETDEWEB)

Schmitt, Theo G.; Gretzschel, Oliver [Technische Univ. Kaiserslautern (Germany). tectraa-Zentrum fuer innovative Abwassertechnologien; Hansen, Joachim [Luxembourg Univ., Kirchberg (Luxembourg). Siedlungswasserwirtschaft und Wasserbau; Siekmann, Klaus; Jakob, Juergen [Ingenieurgesellschaft Dr. Siekmann - Partner GmbH, Thuer (Germany)

2014-03-15

Investigations within the framework of the state-commissioned project ''Re-evaluation of wastewater purification plants with anaerobic sludge treatment with due consideration to framework conditions in terms of the energy and the wastewater management situation in Rhineland-Palatinate'', abbreviated ''NAwaS'', have shown that due to the rise in energy prices and availability of innovative techniques and methods it can be economically efficient, from a plant capacity of 10,000 inhabitants upwards, to convert sewage treatment plants to sludge digestion. Findings from the NAwaS project show the state of Rhineland-Palatinate to have a large potential for the conversion of sewage treatment plants to sludge digestion. Depending on the rate of price increase as well as interest rates the use of digester gas could permit an increase in electricity output by up to 50% over today's levels. Moreover, converted plants would be able to almost completely cover their own heat demand and in addition permit energy savings totalling an expected 5 kWh/(inhabitant x a). If one incorporates the possibilities offered by the procurement of sludge or suitable co-substrates from outside sources, by retrofitting sewage plants with combined heat and power stations or micro gas turbines as well as by process optimisation in existing digestion plants, this gives a further significant increase in potential production capacity and hence economic efficiency. In some of the sewage plants the above measures for saving energy and boosting energy production will even lead to energy self-sufficiency. [German] Die Untersuchungen innerhalb des Landesprojektes ''Neubewertung von Abwasserreinigungsanlagen mit anaerober Schlammbehandlung vor dem Hintergrund der energetischen Rahmenbedingungen und der abwassertechnischen Situation in Rheinland-Pfalz - NAwaS'' haben aufgezeigt, dass aufgrund der gestiegenen Energiepreise und mit innovativen

Application of compound specific 13C isotope investigations of chlorinated hydrocarbons in contaminated groundwaters

International Nuclear Information System (INIS)

Osenbrueck, K.; Heidinger, M.; Voropaev, A.; Ertl, S.; Eichinger, L.

2002-01-01

the stable carbon isotopes. The isotope ratios may be used to assess and quantify the degradation of the organic compounds at the field sites. This application has gained great interest for remediation strategies including monitored natural attenuation of contaminations. In contrast to the laboratory studies, many of the field investigation show no evidence for isotope fractionation although biodegradation of the chlorinated hydrocarbons in the groundwater is significant. Here, we present the results of 21 field studies, where compound specific 13 C isotope ratios have been applied. Only in some cases isotope fractionation processes of chlorinated hydrocarbons due to biodegradation have been observed. The measured δ 13 C values agree reasonably with a Rayleigh type isotope fractionation model, where the fractionation factors are used as fitting parameters. The occurrence and the degree of significant isotope fractionation of chlorinated hydrocarbons is still an open question. Major factors that control the extend of measurable 13 C isotope fractionation of chlorinated hydrocarbons in groundwater most likely include parameters as activity and type of the microbiological species, availability of cosubstrates as well as hydrochemical and hydrogeological conditions. (author)

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, N.; Tuba, F.; Dokgoz, C. [Bioengineering Dept., Faculty of Engineering, Ege Univ., Izmir (Turkey)], E-mail: nuri.azbar@ege.edu.tr

2009-07-01

effluent from dark hydrogen production reactor was not suitable for photo-fermentative hydrogen production. 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. The second conclusion that can be drawn is that cheese whey effluent should be mixed with L-malic acid rich co-substrates such as fruit juice processing effluents before fed into the photo-fermentation reactor. Finally, the two-stage H{sub 2}-producing process could be applied in remediation of lactose-containing industrial wastes, H{sub 2} being used on-site, to reduce process costs via generation of electricity by the help of hydrogen fuel cells. (author)

Monitoring biodegradation of hydrocarbons by stable isotope fractionation

Science.gov (United States)

Dorer, Conrad; Fischer, Anko; Herrmann, Steffi; Richnow, Hans-Hermann; Vogt, Carsten

2010-05-01

nitrate, sulfate or ferric iron as electron acceptor or using light as energy source [3,4,5]. Significantly different lambda values were also observed for the anaerobic degradation of xylenes initiated by the BSS [5]. The different lambda values obtained for the anaerobic degradation of toluene and xylenes might be caused by slightly different reaction mechanisms of BSS isoenzymes. In comparison, lambda and/or ɛbulk values for the methyl monohydroxylation of toluene with oxygen as co-substrate were significantly different for two tested strains each containing a different toluene attacking enzyme, indicating that specific enzymes for aerobic methyl group oxidation reactions can be detected by CSIA and 2D-CSIA. Our results show that the combined carbon and hydrogen isotope fractionation approach has great potential to elucidate biodegradation pathways of monoaromatic hydrocarbons in microcosm and field studies. Current work focus on (i) 2D-CSIA of aromatic and aliphatic hydrocarbons in degradation experiments using whole cells, and (ii) 2D-CSIA of aromatic hydrocarbons in in vitro experiments using cell extracts. [1] Fischer et al. (2008) Environ. Sci. Technol. 42, 4356-4363 [2] Mancini et al. (2008) Environ. Sci. Technol. 42, 8290-8296 [3] Vogt et al. (2008) Environ. Sci. Technol. 42, 7793-7800 [4] Tobler et al. (2008) Environ. Sci. Technol. 42, 7786-7792 [5] Herrmann et al. (2009) Environ. Microbiol. Reports 1, 535-544

Doping dependence of the elastic behaviour of silicon; Dotierungsabhaengikeit des elastischen Verhaltens von Silizium

Energy Technology Data Exchange (ETDEWEB)

Santen, Nicole

2010-02-24

Erzeugung von uniaxialen, externen Spannungen wurden die Proben in Halter mit verschiedenen Kruemmungsradien gespannt, was in der oberflaechennahen, implantierten Schicht Gitterdeformationen von bis zu 0,1% induziert. Es stellte sich heraus, dass p-implantiertes und n-implantiertes Silizium unterschiedlich auf externe Spannungen reagieren, d.h. die resultierende Gitterverzerrung infolge der Probenbiegung haengt von der Art der Dotierungsatome ab. So zeigen Siliziumproben nach Implantation der Akzeptoren B, Al und In das gleiche elastische Verhalten wie undotiertes Silizium. Werden hingegen die Donatoren P, As, Sb und Te implantiert, so beobachtet man eine vollstaendige Relaxation der extern angelegten Spannung in der lokalen Umgebung der Sonden. TEM-Aufnahmen bestaetigen, dass diese Spannungsrelaxation auf Versetzungsringe zurueckzufuehren ist, die sich waehrend der Ausheilung der Implantationsschaeden durch Agglomeration von intrinsischen Fehlstellen gebildet haben. Demzufolge haette die Bildung von Versetzungsringen im gedehnten Kanalbereich von n-MOSFETs fatale Folgen, da diese zu einem unerwuenschten Abbau der Spannungen fuehren, was folglich die Leistungsfaehigkeit integrierter Schaltungen herabsetzen wuerde. (orig.)