VAAM-Jahrestagung 2011 Karlsruhe, 3.–6. April 2011

ecycles organic compounds might be of special relevance to this severelynutrient-depleted habitat.[1] Engelhardt, T. et al (2011): Induction of prophages from deep-subseafloor bacteria. EMIR (inpress).EMP001Biodegredation of 2 – Methooxyethanol by a newbacterium isolate Pseudomonas sp. Strain VB underaerobic conditionsO.F. EkhaiseDepartment of Microbiology, University of Benin, Benin, NigeriaMicrobial biodegradation of 2-methoxyethanol also known as Methyl glycol(MG) under anaerobic conditions has received much attention during thepast decade. However, not much is known about the aerobic degradation of2-methoxyethanol. Samples from various environmental niches wereenriched to isolate and determine bacterial isolates capable of utilizing 2-methoxyethanol as a sole source of carbon and energy under aerobicconditions. A 2-methoxyethanol degrading bacterium was isolated fromanaerobic sludge of a municipal sewage from a treatment plant in Bayreuth,Germany, by selective enrichment techniques. The isolate was designatedstrain VB after it was shown by the 16S rRNA phylogenetic sequenceanalysis as belonging to the genus Pseudomonas. Under aerobic conditionsPseudomonas sp. strain VB was capable of mineralizing 2-methoxyethanoland its intermediary metabolites. Stoichiometrically, the strain utilized onemole of oxygen per one mole of 2-methoxyethanol instead of four moleoxygen per one mole of 2-methoxythanol for the total oxidative metabolism.[1] Daniel, L. et al (1994): Chemical analysis In Gerhardt, P; Murray, E G R; Wood, A W; Krig R N(eds)), Methods for General and Molecular Bacteriology ASM. Press Washingtion, D.C p971.[2] Diekert, G. (1992): The Acetogenic Bacteria. In Balows A. Truper, G.H., Dworkin, M., Harder,W. and Schleifer, K-H (eds). The Prokaryotes. Vol. 1. Springer - Verlag, Erlin. P971.[3] Ekhaise, F. O. (2002): Biodergradation of 2-merhoxyyethanol - isolation, characterizationdegrading bacterium under aerobic conditions. Ph.D. Thesis University of Benin, Benin City, Nigeria.p158.[4] Gerhardt, P. et al (1994): Methods for Genral and Molecular Bacteriology. ASM press, WashintonD.C. p971.[5] Madigan, T. M. et al (2000): Biology of Microorganisms 9 th ed. Prentice Hall, New Jersey, p986.[6] Meyer, O. and G.H. Schelgel (1983): Biology of aerobic carbon monoxide-oxidizing bacteria.Ann. Rev. Microbiol 37:277-310.[7] Pottrawtke, T. et al (1998): Degradation of 1,2,3,4 - Tetrachlorobenzene by Pseudomonaschlorophis RW71. Appl. Envion. Microbiol. 64: 3798-3806.[8] Rainey, F. A. et al (1996): The genus Nocardiopsis represents a phylogenetically coherent taxonand a distinct actinomycete lineage: Proposal of Nocardiopsceas fam. Nov. Int. J. Syst. Bacteriol. 46:1088-1092.[9] Tanaka, K. (1986): Methane fermentation by mesophilic digesting sludge. J. Ferment. Technol.64:305 – 30.[10] Tanaka, K. and N. Pfenning (1988): Fermentation of 2-methoxyethanol by Acetobaceriummalicum sp. Nov and Pleobacter venetianus. Arch. Microbiol 149: 181 - 187.EMP002The Molybdenum Storage Protein - a special kind ofmetalloproteinJ. Poppe* 1 , B. Kowalewski 2 , K. Schneider 2 , U. Ermler 11 Deparmtnet of Molecular Membrane Biology, Max Planck Institute ofBiophysics, Frankfurt, Germany2 Faculty of Chemistry, University of Bielefeld, Bielefeld, GermanyThe diazotrophic soil bacterium Azotobacter vinelandii utilizes a FeMocofactorcontaining nitrogenase in larger amounts to accomplish nitrogenfixation. This requires a lot of molybdenum, which is extracted from theenvironment and stored in a special Molybdenum Storage Protein (MoSto).This extraction strategy is rather efficient and limits the available Mocontents for other soil bacteria.The MoSto is a remarkable protein due to its capability to store hugeamounts of Mo in form of polyoxomolybdate clusters [2]. X-ray studies ofthe loaded MoSto after purification revealed different types of Mo-oxidebased clusters some being covalently bound while others are not. Synthesisof these clusters is an ATP-dependent process whose mechanism is not yetknown. In-vitro experiments showed that it is possible to fully deplete theMoSto of its metal clusters and later on reload it again. The depletion provedto be a pH-driven triphasic process which can be varied with temperatureand time of incubation [1]. Depending on the method of protein purificationthis can lead to a total reload of 120 Mo-atoms per protein molecule. Furtherresearch is necessary to determine the way the clusters are built from singleMo-ions and how their release from MoSto is organized.[1] J. Schemberg et al (2008): ChemBioChem, 9, 595-602.[2] D. Fenske et al (2005): ChemBioChem, 6, 405-413.EMP003Impact of extreme weather events on the microbialfunction of soilV. Hammerl* 1 , K. Pritsch 2 , A. Jentsch 3 , C. Beierkuhnlein 4 , M. Schloter 1,21 Department of Soil Ecology, Technical University Munich, Neuherberg,Germany2 Department of Soil Ecology, Helmholtz Center for EnvironmentalResearch (UFZ), Munich, Germany3 Department of Geoecology and Physical Geopgraphy, University ofLandau, Landau, Germany4 Department of Biogeography, University of Bayreuth, Bayreuth, GermanyProlonged drought periods as predicted in future climate scenarios willaffect ecosystem functions in multiple ways. Water stress not only affectsplants but also soil microorganisms. As important soil functions, nutrientturnover processes will be affected during the vegetation period when plantshave highest demands. Drought is one of the factors addressed in theEVENT-Experiment established at the Botanical Garden of the University ofBayreuth. In this project, we hypothesise that hydrolytic enzyme activitieswill be reduced and oxidative processes will be favoured under droughtconditions. Therefore, biochemical parameters such as soil enzymaticactivities of hydrolytic (phosphatase, chitinase, proteases, cellulases) andoxidative enzymes (phenoloxidases, peroxidases) are measured. In additionthe gene and transcript pool of these enzymes will be studied usingmolecular biological studies on nucleic acids extracted from soil (chitinase,cellulases, xylosidase). The project focuses on experimental and naturalgrassland communities. First results will be presented on drought effects(1000 year extremes) and an outline of the overall design of the study ispresented.EMP004Low-temperature denitrification in wastewater by usingof encapsulated biomass: The choice of appropriateorganismL. Vacková* 1 , M. Srb 1 , R. Stloukal 2 , J. Wanner 11 Institute of Chemical Technology Prague, Department of WaterTechnology and Environmental Engineering, Praha, Czech Republic2 LentiKat's a.s., Praha 6, Czech RepublicWastewater treatment is one of the fields of industrial application ofmicrobial processes. Recently, the biological treatment is provided by socalledactivated sludge, the dynamic polyculture containing huge number ofbacterial species.This technology can be modified, for example by using encapsulatedbiomass. This kind of immobilisation technique encases the microorganismsinto porous polymerous gel, in the case of our study into polyvinylalcohol.The structure of gel enables diffusion of substrate to organisms as well asthe microbial growth, but prevents the bacteria from outside of the pelletfrom intrusion to the inside. As the pellet contains only bacterial speciesintroduced during the fabrication process, careful selection of suitableculture to be immobilized is necessary.The denitrification process in wastewater as well as in drinking watertreatment can be slowed down by low temperature of water. In this study,three types of immobilized denitrification cultures have been compared. Thefirst type contained pure culture of Paracoccus denitrificans with optimaltemperature of 30 - 37 °C [1], which has already been used for fullscaledenitrification [2]. The second type contained pure culture of Pseudomonasfluorescens as a representative of psychrophilic bacteria. The last typecomprised of highly-adapted mixed culture of psychrophilic denitrifierscultivated for one year at 5 °C from activated sludge.The aim of this work was to compare denitrification activity of these typesof encapsulated biomass. The experiments were held with syntheticwastewater containing 50 mg·L -1 N-NO 3 - under the temperature 15, 10, 8and 5 °C. Specific denitrification rates were calculated and the temperaturecoefficients describing the dependence of denitrification rate on thetemperature were determined. The culture composition and dislocationwithin the pellets was observed. Since the low-temperature denitrification issupposed to be performed in industrial-scale, it is necessary to consider notonly the denitrification rates and courses, but also the possibility of easy,steady and sustainable cultivation when choosing appropriate organism.[1] Garrity, G.M. et al (2005): Bergey's Manual of Systematic Bacteriology, Volume Two: TheProteobacteria, Parts A - C, Springer - Verlag, pp. 323-369.[2] Mrákota, J.et al (2010): Dočištění dusičnanového dusíku pomocí biotechnologie lentikats naodtoku z reálných ČOV. in: Odpadové vody 2010, (Eds.) I. Bodík, M. Hutňan, Vydavatel'stvo VÚP -OI. Štrbské Pleso, pp. 145-150.spektrum | Tagungsband 2011