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

Our goal is to enhance process understanding particularly related to scalingand corrosion processes of engineered geothermal systems to contribute tothe optimization of plant reliability.Hallmann, C., Rüdrich, J., Enseleit, M., Friedl, T., Hoppert, M. (2010)Microbial diversity on a marble monument: a case study. Environ Earth Sci -DOI 10.1007/s12665-010-0772-3EMP125Short term response of a pristine indoor aquifer systemto a simulated toluene spillA. Herzyk* 1 , M. Larentis 1 , K. Hoermann 1 , T. Lueders 1 , C. Griebler 1Institute of Groundwater Ecology, Helmholtz Center, München, GermanyThe intrinsic potential of groundwater ecosystems to recover fromhydrocarbon contamination is of prime concern when it comes to protectionand sustainable management of groundwater resources. However it needs indepthunderstanding of biological, geochemical and hydrological processesat pristine and contaminated sites to substitute descriptive research byassessment of approaches with predictive power.A pristine sandy indoor aquifer has been designed mimicking oligotrophicgroundwater aquifer which allows a thorough system characterisation atnon-impacted conditions followed by a spatio-temporal highly resolvedinvestigation of system response upon toluene injection and during itsrecovery.Although there is a pile of lab studies on natural attenuation of aromatichydrocarbons, none have comprehensively addressed the followingconcerns: (i) what is the time scale for an ecosystem reaction (efficientbiodegradation) towards organic contamination in case of a pristine aquifer?(ii) does the indigenous microbial diversity add pronounced resilience to thesystem and can microbial patterns be used as indicators for ecosystem statusassessment? (iii) is there a quantitative correlation between degradersabundance and a distribution of respective degradation genes and processes?(iv) does the ecosystem return to its original status after removal ofcontamination and how fast?First obtained results, prove an immediate response of the indoorgroundwater ecosystem to toluene introduction. Screening of bacterialcommunity composition via T-RFLP fingerprinting revealed a decreasingdiversity inside and at the fringes of the toluene plume. This wasaccompanied by increasing total cell counts, higher ATP values andincreased bacterial carbon production rates. A relative maximum of genesencoding for toluene degradation shortly hints at fast establishment ofspecific degradation lineages in the intrinsic groundwater (and sediment)community. Already after 4 weeks of constant toluene injection a netdecrease of toluene, rapid oxygen depletion in the center of the plume anddisappearance of sensitive members of the community was observed.The indoor aquifer provides an ideal playground to assess the impact oftoluene contamination and the natural attenuation potential of groundwaterecosystems.EMP126Fungal and green algal microbial communities on naturalstone surfacesC. Hallmann* 1 , L. Stannek 2 , D. Fritzlar 2 , M. Hoppert 21 Albrecht-von-Haller-Institute for Plant Sciences – ExperimentalPhykology, Georg-August-University, Göttingen, Germany2 Institute for Microbiology und Genetics, Georg-August-University,Göttingen, GermanyMicrobial biofilms, consisting of green algae, filamentous fungi andbacterial organisms cover solid surfaces, such as plastic material, glass andnatural stone. In the present study, biofilm samples from diverse dimensionstone surfaces where used to analyze the diversity of bacteria, green algaeand filamentous fungi in a comparative approach. Isolated organisms wereused to unravel their strategies for adhesion to stone surfaces and forendolithic growth.The overall diversity of certain groups markedly differs with respect tocertain features of the stone surface. Analysis of cloned sequences obtainedfrom environmental DNA revealed that surfaces covered with thin gypsumcrusts are preferentially colonized by unicellular cyanobacteria. On othersurfaces (sandstone, limestone), green algal species dominate.The diversity of filamentous fungi rather depends on exposure of the stonesurface to sunlight: From W-exposed, shaded surfaces, free livingascomycetes, mainly melanized black fungi, could be retrieved. An ESE,sun-exposed surface was barely colonized; the retrieved organisms weremainly lichen ascomycetes and the lichen alga Trebouxia.FBV001Grey mould isolates from German strawberry fieldsreveal a new type of multidrug resistance and evidencefor a novel taxon next to Botrytis cinereaC. Plesken* 11 TU Kaiserslautern, Phytopathology, Kaiserslautern, GermanyCecilia Plesken, Manuel Daumann, Michaela Leroch, Matthias Hahn.Dept.of Biology, University of Kaiserslautern, P.O. box 3049, 67653Kaiserslautern, GermanyBotrytis cinerea is a destructive pathogen of many fruit and and vegetablecrops worldwide, which needs to be controlled by fungicide treatments incommercial cultures. We have recently described the wide-spreadappearance of grey mould strains in vineyards with reduced sensitivities todifferent fungicides (MDR phenotypes), due to increased drug efflux activitycaused by the overexpression of two genes encoding ABC- and MFS-typetransporters. We have extended our analysis to strawberry fields, whichreceive many fungicide treatments during flowering. A high proportion ofgrey mould isolates from strawberries showed high frequencies of resistanceto all currently used fungicides. We also detected a new MDR phenotype(MDR1 h ), with higher resistance levels than MDR1. This phenotype iscorrelated to even higher constitutive levels of the atrB ABC transportergene. MDR1 h isolates were found to be genetically distinct, showingsignificant sequence divergence compared to known B. cinerea strains. Weare currently analyzing the taxonomic status of these isolates and themutations leading to MDR1 h .FBV002Mutations and migration of Botrytis cinerea field strainswith multidrug resistance phenotypes in French andGerman vineyardsD. Mernke*Plant Pathology Group, University of Kaiserslautern, Kaiserslautern,GermanyDennis Mernke, Andreas Mosbach, Michaela Leroch, Matthias Hahn.Dept.of Biology, University of Kaiserslautern, P.O. box 3049, 67653Kaiserslautern, GermanyBotrytis cinerea is a destructive pathogen of many fruit and and vegetablecrops worldwide, which needs to be controlled by fungicide treatments. InFrench and German vineyards, B. cinerea strains with multiple fungicideresistance (MDR) phenotypes have been observed with increasingfrequencies. MDR results from mutations that lead to constitutiveoverexpression of genes encoding drug efflux transporters. In MDR1 strains,several point mutations in a transcription factor encoding gene (mrr1) havebeen identified that lead to constitutive activation of the ABC transportergene atrB. In MDR2 strains, overexpression of the MFS transporter genemfsM2 has been found to result from two rearrangements in the mfsM2promoter caused by insertion of a retroelement (RE)-derived sequence.MDR2 strains containing the type A rearrangement are widely distributed inFrench and German vineyards, while strains with type B rearrangement havebeen found only in the Champagne. MDR2 strains harbouring either mfsM2type A or type B mutations show the same resistance phenotypes, andsimilar overexpression of mfsM2. Population genetic analyses wereconducted that support the hypothesis that the two MDR2-related mutationshave only occurred once, and are responsible for the appearance andsubsequent spread of all known MDR2 strains in French and German winegrowingregions.spektrum | Tagungsband 2011