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

clinical isolates demonstrating that sponge associated bacteria are a richsource for novel bioactive compounds.EMP045Changes in diversity and abundance pattern of microbialcommunities involved in nitrogen fixation, nitrificationand denitrification comparing a tidal wetland to paddysoils cultivated for different time periodsA. Bannert*, K. Kleineidam, M. SchloterTerrestrial Ecogenetics Department (TEG), Helmholtz Center Munich,Oberschleißheim, GermanyIn many areas of China tidal wetlands have been converted into agriculturalland for rice cultivation. However, the consequences of land use changes forsoil microbial communities are poorly understood. Therefore, weinvestigated bacterial and archaeal communities involved in inorganicnitrogen turnover (nitrogen fixation, nitrification and denitrification) basedon abundance pattern and relative species richness of the correspondingfunctional genes along a soil chronosequence ranging between 50 and 2000years of paddy soil management compared to a tidal wetland. Changes inabundance and diversity of the functional groups could be observedreflecting the different chemical and physical properties of the soils, whichchanged in terms of soil development. The tidal wetland was characterizedby a low microbial biomass and relatively high abundances of ammoniaoxidizing microbes. Conversion of the tidal wetlands into paddy soils wasfollowed by a significant increase in microbial biomass. 50 years of paddymanagement showed a higher abundance of nitrogen fixing microbescompared to the tidal wetland, whereas dominant genes of nitrification anddenitrification showed no differences. With ongoing rice cultivation copynumbers of archaeal ammonia oxidizers did not change, while that of theirbacterial counterparts declined. The gene coding for the nitrite reductionnirK, which was dominating over its functional redundant counterpart nirSat all sites increased with rice cultivation time in all soils. Relative speciesrichness showed significant differences between all soils with the exceptionof archaeal ammonia oxidizers in the paddy soils cultivated for 100respectively 300 years. In general, changes in diversity pattern were morepronounced than in abundance pattern.EMP047Characterization of a new Nitrospira in competition toknown nitrite oxidizing taxa of activated sludge samplesfrom waste water treatment plantM. Kruse* 1 , E. Spieck 2 , E.P. Bakker 3 , A. Lipski 11 Department of Food Microbiology and Hygiene, Friedrich-WestphalianWilhelms-University, Bonn, Germany2 Microbiology, Biocenter Klein Flottbek, Hamburg, Germany3 Department of Microbiology, University of Osnabrück, Osnabrück,GermanyThe nitrification process is one of the most important tasks for modernwastewater treatment. Because cultivation of this autotrophic community isdifficult and time-consuming, direct methods targeting to both, identity andactivity of nitrifying bacteria, became most important for the analysis of thisprocess. This study is based on analyses of the active Nitrospira populationin activated sludge samples from the municipal waste water treatment plantof Hamburg (Germany). The autotrophic bacterial community was labeledwith 13 C-carbonate and analyzed by FAME-SIP. With FAME-SIP it waspossible to detect the metabolically-active autotrophic bacterial communityin environmental samples. We combined these chemotaxonomic analyseswith cloning of the 16S rRNA and fluorescence in situ hybridization (FISH).A new Nitrospira was detected by means of a characteristic fatty acid profilewhich was different from that one of Candidatus Nitrospira defluvii. Thelabeled compound was the cis 7 isomer of hexadecanoic acid. This lipid wasnot described before for nitrite-oxidizers from activated sludge. Theseresults were supported by a new 16S rRNA gene sequence achieved by acloning approach. This sequence was allocated to the Nitrospira branch butdifferent from known sequences. Further on cells of Nitrospira weredetected with fluorescence in situ hybridization performed with specificprobes designed for the new Nitrospira variant. The labeling experimentsgave important hints for promising enrichment conditions for this organism.The analyses showed highest incorporation of label at temperatures of 17 -22°C with low nitrite concentrations of 0.3 mM for the new characteristicNitrospira-related compound from activated sludge, the fatty acid 16:1 cis 7.Based on FAME-SIP analyses, the competition of Nitrospira populationswith other autotrophic nitrite oxidizing bacteria such as Nitrobacter andNitrotoga were analyzed in activated sludge samples under differentincubation conditions.EMP046Bacteriophages as indicators for changes of the activemicrobial community in BTEX contaminated systemsB. Kiesel*, I. Fetzer, A. Chatzinotas, A. HeidtmannDepartment of Environmental Microbiology, Helmholtz Center forEnvironmental Research (UFZ), Leipzig, GermanyA pilot-scale plant was set up at a former refinery site near Leuna(Germany) as a Compartment Transfer (CoTra) project to investigateefficient low-cost and near-natural remediation strategies for BTEXcontaminated groundwater (up to 15 mg/l). Significant changes indegradation but also in microbial community composition were postulated.Since bacteriophages represent one of the major factors regulating bacterialabundance and diversity, the question arose whether the development of thebacteriophage community potentially mirrors changes in bacterialcommunity composition.In this study we aimed at (i) an inventory of the phage abundances ingroundwater samples and the two different treatment systems of the CoTrapilot plant, i.e. the constructed wetlands (AP2) and the aerobic trenches(AP5), (ii) an analysis of the composition of the phage community itself, andfinally (iii) an evaluation of the option to use transducing phages foridentifying the active and thus BTEX consuming part of the microbialcommunity.The amount of phage particles was found to be nearly constant over the yearwith phage titres between 1x10 8 and 2x10 9 phages/ml in the treatments andthe contaminated groundwater and 10-fold less titre in uncontaminatedgroundwater. Based on PFGE separation of concentrated phages 7-9different main phage genome sizes were differentiated. Mispackedchromosomal 16S rDNA in so-called „transducing phage particles” allowedto identify growing bacteria as phage hosts and to detect them within thewhole bacterial community. The data are discussed with particular referenceto two contrary hypotheses for the function of phages in ecosystems, termedas either „surviving of the fittest” or „killing the winner” hypothesis.EMP048Optimization of Culture Conditions for PyrogallolProduction from Gallic acid by Enterobacter sp.M. Soni* 1 , K.P. Sharma 2 , P.J. John 11 Department of Zoology, University of Rajasthan, Jaipur, India2 Department of Biotechnology, Mody Institute of Technology and Science,Sikar, Rajasthan, IndiaThe process of tannin biodegradation is initiated by tannase which convertstannic acid into gallic acid. The second step of this pathway is catalyzed bygallic acid decarboxylase which converts gallic acid into pyragallol.Pyragallol has widespread industrial applications as it is used as a developerin photography, for staining fur, leather and hair, for manufacturing variousdyes, and for determining oxygen in gas analysis. In the present study amicroorganism was isolated from soil and identified as Enterobacter sp.Culture conditions for the maximum production of pyrogallol from gallicacid were optimized with the isolate. The maximal production of pyrogallolwas observed when the bacterium was cultured at 30°C for 20 hrs in amedium containing 0.2 % gallic acid, 0.4 % (NH 4) 2SO 4, 30 mM phosphatebuffer pH 6.6, 0.05% MgSO 4, 0.001% FeSO 4. The other parametersoptimized are incubation time, incubation temperature, agitation speed,Inoculum age and Inoculum size.spektrum | Tagungsband 2011