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

quantitative PCR. In situ nitrification activities as well as the relativeimportance of planktonic microbial communities versus communities thatare associated with the aquifer matrix for nitrogen transformation processesremain to be investigated.EMP086Comparative occurrence and detectability of fumarateaddingdegradation genes in hydrocarbon-contaminatedanaerobic aquatic ecosystemsF. von Netzer* 1 , G. Pilloni 1 , F. Gründger 2 , S. Kleindienst 3 , M. Krüger 2 ,K. Knittel 3 , T. Lueders 11 Institute of Groundwater Ecology, Helmholtz Center Munich, Neuherberg,Germany2Federal Institute for Geosciences and Natural Resources,Geomicrobiology, Hannover, Germany3 Department of Molecular Ecology, Max Planck Institute for MarineMicrobiology, Bremen, GermanyThe degradation of hydrocarbons via the addition of fumarate to methylgroups is an important catabolic pathway in anaerobic ecosystemscontaminated with hydrocarbons of natural or anthropogenic origin. Becauseof the unique reaction mechanism, genes for fumarate adding enzymes(FAE) are an ideal genetic marker for the targeted detection of bacteriainvolved in anaerobic hydrocarbon degradation. The knowledge about theoccurrence and diversity of anaerobic hydrocarbon degrader populationsgives important insights into the structure and function of degradercommunities as well as natural attenuation.FAE sequences show a ramified phylogeny which is determined by bothdegrader affiliation as well as substrate spectrum. It has been shown thatdistinct gene lineages can be recovered by different specific primer sets, i.e.as for enzymes involved the degradation of monoaromatic, polyaromatic andaliphatic hydrocarbons. However, a thorough assessment of degraderdetectability in contaminated samples by different assays and also rapidscreening tools are still at lack. Here, by a comparative screening for FAEsin hydrocarbon-impacted samples of marine, subsurface and limnic originwe provide new insights into the global distribution of key anaerobichydrocarbon degradation gene pools. By a bssA-targeted T-RFLP assay,additional insight into the diversity and relative abundance of key FAE genelineages within degrader populations are given. Comparing the results ofFAE gene detection with ribosomal markers, it even becomes possible toassociate previously unidentified FAE lineages to defined taxonomic phyla,as we demonstrate for 13 C-enriched DNA of uncultured toluene degraderswithin the Desulfobulbaceae, which were detected in a stable isotopeprobing experiment with contaminated aquifer sediments.EMP087Metagenomics and metatranscriptomics of theRoseobacter cladeB. Wemheuer*, D. Meier, R. DanielInstitute of Microbiology and Genetics, Genomic and Applied Microbiology,Göttingen, GermanyThe Roseobacter lineage is a widely distributed, abundant andbiogeochemically relevant group of marine bacteria. Members of the cladehave been identified in a large variety of habitats (costal and polar regions,open oceans, ice, saline lakes and hypersaline lakes). The use of a multitudeof organic compounds, the production of secondary metabolites, and othermetabolic pathways contributes to the success of the group in marineenvironments.This study was focused on assessing and exploiting the diversity andmetabolic potential of uncultivated members of the Roseobacter clade andother marine microorganisms. In this survey, samples derived from theGerman Sea were analysed by metatranscriptomic and metagenomicapproaches.To gain insights in the metabolic potential, RNA was extracted from filteredsea water samples. For metatranscriptomic analyses, the RNA was purified,ribosomal RNA was removed and enriched mRNA converted to cDNA. Theresulting cDNA was sequenced by 454 pyrosequencing and further analysed.To analyse bacterial diversity, a two step 16S rRNA RT-PCR and a 16SrDNA PCR were performed. The generated amplicons were sequenced by454 pyrosequencing and further analysed. The Roseobacter lineage wasabundant in all samples. Other bacterial phylotypes were also identified, e.g.the SAR11 clade, another group of abundant marine bacteria.Along with the other studies, high-molecular weight DNA, extracted fromthe samples, was used for the construction of metagenomic large-insertlibraries. The generated libraries were afterwards prospected for proteolyticactivity by a function-driven approach. So far, two novel genes conferringproteolytic activity were identified.EMP088From grapes to wine: Monitoring the development ofyeast populations by FT-IRD. Gerhards* 1 , C. Lehnigk 1 , N. Büchl 2 , M. Wenning 2 , S. Scherer 2 , C. vonWallbrunn 11 Department of Microbiology and Biochemistry, Geisenheim ResearchCenter, Geisenheim, Germany2 Research Center for Nutrition and Food Sciences, Technical UniversityMunich, Freising, GermanyNowadays the wine production is mainly based on the use of commercialstarter cultures of Saccharomyces cerevisiae yeast strains. Neverthelessspontaneous fermentations carried out by non-Saccharomyces yeasts are acommon mode in wine production. This can lead to wines with more distinctaromas on the one hand, but wines with off-flavours, partly unsuitable forsale, on the other side.Wild yeasts derived from the vineyard and the cellar equipment are knownto be very important for the wine quality of spontaneously fermented musts.Therefore, in this project promoted by the AIF yeasts on Riesling grapesfrom six vineyards regarding different habitats and soil types in Germanywere analyzed. The yeast populations were monitored at three differentstages pre harvest and at six phases during the spontaneous fermentation. Ateach sampling point 100 randomized isolated yeasts were identified. Theidentification was accomplished by FT-IR technology, which allowshandling such a quantity of isolates, to gain knowledge of the yeast diversityduring wine making.The results demonstrated that twelve main yeast species like Hanseniasporauvarum (up to 90 %), Candida oleophila and C. boidinii (up to 54 %) anddifferent Metschnikowia and Pichia species (~ 10 %) run through the firstthird of the fermentation process before it is dominated by Saccharomycescerevisiae. The proportion of other species such as Torulaspora delbrueckii,Debaryomyces hansenii and D. polymorphus or Issatchenkia orientalis issmall. Interestingly it seems that yeasts responsible for fermentationoriginating from the grape surface and coming in the cellar are in theminority. Depending on the phytosanitary status of the grapes, genera likeAureobasidium, Rhodotorula, Cryptococcus or Sporidiobolus are the mainyeasts (up to 100 %) on the surface of the grape berries. These are irrelevantfor the fermentation process. Therefore yeasts coming from the cellarequipment have a strong influence on the whole population during thefermentation process.The FT-IR technology leads to a better insight on yeast populations incontrast to molecular based methods, but is still limited corresponding to thetotal cell count. Using specific media, further studies showed, thatfermentation relevant organisms are present on the grapes. Usually theseyeasts are under the detection limit, if 100 randomly selected yeasts persample were isolated.EMP089Alteration of compost and topsoil microbial communitiesaffected by acid mine drainageM. Reinicke*, F. Schindler, E. KotheInstitute of Microbiology, Department of Microbial Phytopathology,Friedrich-Schiller-University, Jena, GermanyMining processes are widespread over the whole world and independent ofthe mined material, formation of acid mine drainage (AMD) is a basicproblem off all mines. Through oxidation and natural leaching processes,immobile heavy metals become mobile in the water fraction and alsobioavailable for all organisms. Most of these mobile heavy metals areharmful for organism, like bacteria, plants and animals.To handle the heavy metal pollution and to remediate contaminated areas,the addition of soil, especially compost, is a first step in phytoremediation.With this soil addition a great number of bacteria are also added to a newenvironment with harmful conditions. The non-adapted microbialcommunities have to cope with these contaminants and to developetolerance or resistance.At our study and sampling site near Ronneburg (Thuringia, Germany)uranium mining was performed there for over 40 years. Heavy metals werespektrum | Tagungsband 2011