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

EMP058Functional diversity of microbial biofilm communitiesgrowing on some halogenated compoundsA.S. Gebreil* 1,2 , W.-R. Abraham 11 Deparment of Chemical Microbiology, Helmholtz Institute for InfectionResearch, Braunschweig, Germany2 Department of Biology, University of Technology, Braunschweig, Germanyγ-Hexachlorocyclohexane (γ-HCH) and 4,4`-diphenylether (DFE) arehalogenated pollutants that persist in the environment for a long time.Although degradation of such compounds by either bacteria or fungi is verydifficult, nevertheless, bacteria and fungi within a community can help eachother making the degradation process easier. The purpose of the presentwork was to determine the extent of microbial potential for the degradationof γ-HCH and DFE in soils. This study addressed the huge diversity ofbacteria and fungi from 12 soil samples collected around insecticide andpesticide producing factories in Egypt. From γ-HCH and DFE enrichmentcultures, all samples yielded high biodiversity as revealed by the analyses ofthe16S rDNA genes for bacteria and 18S rDNA genes for Fungi. Soil andsediment samples were used to inoculate γ-HCH and DFE microcrystals ona substratum (Permanox TM ) in microcosms to grow complex biofilmcommunities on γ-HCH and DFE. The biofilms were monitored for about 42days by community fingerprinting using single strand conformationalpolymorphism (SSCP) of 16S rRNA and 18S rRNA gene amplicons. Allsoil samples yielded biofilms on both γ-HCH and DFE. SSCP analyses ofthe biofilms revealed rather diverse bacterial and fungal communities. TheStructural biofilm development was monitored by Confocal Laser ScanningMicroscope (CLSM) using SYBRO, to stain proteins, DAPI to stain DNAfor all bacteria and Bac Light kit bacterial viability check (live (green)/DEAD (red)). From the soil samples, multispecies were obtained and mostof them could use γ-HCH and DFE as sole source of carbon in a minimalmedium. Bacteria and Fungi in microbial communities play different rolesand together were able to form biofilms using γ-HCH and DFE as a carbonsource (a functional diversity cooperation). The metabolites of thebiodegradation of the two compounds were characterized by GC/MS. Themolecular characterization of gene family encoding for the, linA, linB andlinC, γ-HCH-degrading enzymes in the bacteria is in progress.EMP059Association of hygienically relevant bacteria withfreshwater planktonM. Tewes*, J. Frösler, H. Petry-Hansen, H.-C. Flemming, J. WingenderBiofilm Center, Aquatic Biotechnology, University of Duisburg-Essen,Duisburg, GermanyIn the present study the colonization of plankton organisms by differentcategories of hygienically relevant bacteria was investigated in amesotrophic lake (Lake Baldeney, Germany). The target organisms werefaecal indicator bacteria (coliforms, Escherichia coli, intestinal enterococci,Clostridium perfringens), obligate pathogens of faecal origin(Campylobacter spp.) and potentially pathogenic environmental bacteria(Legionella spp., Pseudomonas aeruginosa, Aeromonas spp.). Monthlysampling (April to September 2010) of water, phytoplankton andzooplankton was performed at three transects across the lake. Theabundance of the bacteria was determined by cultural methods and in thecase of legionellae and P. aeruginosa additionally by culture-independentquantitative polymerase chain reaction (qPCR).The concentration of all faecal indicator bacteria, Aeromonas spp. and P.aeruginosa that were attached to plankton was generally higher compared tothat in the water phase. Camplyobacter jejuni and Campylobacter coli werequalitativley detected in water and on phytoplankton, but not onzooplankton. P. aeruginosa was only found in low concentrations in waterand on plankton, while Legionella spp. could not be detected by cultivation.However, using qPCR P. aeruginosa and Legionella spp., but not themedically important species Legionella pneumophila, were found in allsamples at levels of about 10 4 - 10 6 genome units/L in free water and atseveral log units higher concentrations on phyto- and zooplankton. This mayindicate that at least part of the legionellae and P. aeruginosa populationsexisted in a viable but nonculturable state.This study shows that diverse species of hygienically relevant bacteriaaccumulate on plankton which can thus act as a vector and reservoir forthese organisms. This observation may be relevant for the epidemiologicalrisk assessment of the human use of surface water for recreational purposesand as source water for drinking water production.EMP060Detection of viruses in the Jordan valley and eliminationin laboratory soil columnsC. Zawadsky*, N. Schmidt, A. TiehmDepartment of Environmental Biotechnology, Water Technology Center(WTZ), Karlsruhe, GermanyIn particular in arid regions the reuse of waste water is an important issue.As part of the SMART Jordan Valley project (www.iwrm-smart.org), newintegrated approaches for water management and aquifer recharge aredeveloped. Elimination of pathogens and persistant pollutants represent keyfactors in integrated water resources management, and identifying suitabletreatment processes to eliminate such compounds becomes inevitablynecessary.Waste water, groundwater, and surface water samples have been taken inJordan and Palestine since spring 2007 and were analysed with respect toviruses (adenoviruses, rotaviruses group A, noroviruses genogroup I, andMS2 bacteriophages). In our study an advanced cation-coated filter methodwas developed to concentrate pathogens in large volumes of water, followedby PCR. A total of 23 water samples were examined. In 69% of the samplesat least one group of viruses was detected. MS2 bacteriophage appearedtogether with the other viruses. Rotavirus group A was dominating. Theresults are consistent with previous reports since rotaviruses seem to beubiquitous.Preliminary laboratory soil infiltration studies were conducted with twoflow-through soil columns under unsaturated, aerobic conditions at twodifferent temperature settings (2°C and 20°C) to study virus elimination.Soil columns were spiked with MS2 bacteriophages in high concentrationsand breakthrough of phages was followed for 84 days. Both, with plaqueassay and qualitative PCR the model virus was detected at lowconcentrations in the effluent at 2°C, but not at 20°C. The column studyconfirmes that Soil-Aquifer-Treatment can significantly contribute to thereduction of microbiological pollutants. Future studies will include theoperation of pilot systems for aquifer recharge in the Jordan Valley.Funding by the German Federal Ministry of Education and Research (projectno. 02WM1082) is gratefully acknowledged.EMP061Electron acceptor-dependent identification of keyanaerobic toluene degraders at a tar-oil contaminatedaquifer by Pyro-SIPG. Pilloni, F. von Netzer, T. Lueders*Institute of Groundwater Ecology, Helmholtz Center Munich, Neuherberg,GermanyBioavailability of electron acceptors is probably the most limiting factor inthe restoration of anoxic, contaminated environments. Particularly inaquifers, the oxidation of contaminants such as aromatic hydrocarbons oftendepends on the reduction of ferric iron or sulphate. At a tar-oil contaminatedaquifer in Germany, we have previously detected a highly active fringe zonebeneath a toluene plume, where a specialized population of degraders codominatedby Desulfobulbaceae and Geobacteraceae had established [1].Although on-site geochemistry links degradation to sulfidogenic processes,dominating degradation genes in situ appeared related to Geobacter spp [2].Therefore, a stable isotope probing (SIP) incubation of sediment sampleswith 13 C 7-toluene and comparative electron acceptor amendment wasperformed. We introduce pyrosequencing of templates from SIP microcosmsas a powerful new strategy in SIP gradient interpretation (Pyro-SIP). Ourresults reveal the central role of Desulfobulbaceae for sulfidogenic toluenedegradation in situ, and affiliate detected catabolic genes to this lineage. Incontrast, Betaproteobacteria related to Georgfuchsia spp. became labelledunder iron-reduction. The almost absolute absence of Geobacter spp. in SIP-DNA excludes its relevance as toluene degrader in situ. Furthermore,secondary toluene degraders within the Peptococcaceae detected under bothredox conditions prompt hypotheses about niche-differentiation andfunctional redundancy within degradative potentials on site.[1] Winderl et al (2008): Appl Environ Microbiol 74, 792.[2] Winderl et al (2007): Environ. Microbiol. 9, 1035.spektrum | Tagungsband 2011