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

selected phyllosphere bacteria was investigated using a DGGE-analysis.Two primer systems for alpha and gamma proteobacteria were used.The main groups of isolates could be found in both sampling periods, allsampling sites and all land-use types. Analysis of the 16S rRNA genesequences confirmed that all isolates belong to the genus Methylobacteriumwith similarities between 97.3 and 100% to described species (M.marchantiae, M. adhaesivum, M. mesophilicum, M. organophilicum, M.jeotgali). Additionally, a new Methylobacterium species was found. UsingDGGE, 96 leaf samples of T. repens from 3 sampling sites and differentland-use types were analysed. First results suggest that some communitymembers of the selected alpha proteobacteria occur on leaves of all differentland-use types and both sampling periods. Using isolates from the sameleaves as standards showed that the main community members seem to beMethylobacterium species. The composition of the selected gammaproteobacteria seems not to be influenced by land-use type.MDP005Influence of trans-resveratrol on the Lactobacilluspopulations of the human gutJ. Beyer*, L.M. Bode, A. Hanak, M. Huch*, G.-S. Cho, S. Kulling, C. FranzSafety and Quality of Fruit and Vegetables, Max Rubner Institute,Karlsruhe, GermanySo far, little is known about the effect of secondary plant compounds on thecomposition of the human gut microbiota. Resveratrol was shown tofavourably influence the Lactobacillus and Bifidobacterium populations inthe gut of rats with DSS induced colitis. In this study, it was investigatedwhether resveratrol or resveratrol related compounds influenced thecomposition of bacteria in human faeces in vitro, with special reference toLactobacillus populations, using culture-dependent and culture-independenttechniques. The faecal microbiota of two individuals studied in vitro wasnoticeably different, which is in agreement with previous findings that thehuman microflora composition varies considerably between individuals.With the culture-independant DGGE technique, the gut microbiota appearedto be uninfluenced by resveratrol and related compounds, with onlypterostilbene resulting in a small change in DGGE pattern of only one banddifference. All other compounds, including resveratrol, piceid, ε-viniferin,piceatannol, hopeaphenol, amelopsin, ε-, R-, and R-2 viniferin, isoharpontinand trimethoxyresveratrol showed no clear effect on the faecal microbiota.For the experiments with resveratrol, culture-dependent techniques wereused in addition to the culture-independent techniques to evaluate theinfluence of this compound on the microbial composition of the faecalmicroflora. In contrast to the results obtained with DGGE, these resultsshowed that resveratrol led to an increase in the proportions of lactobacilliand bifidobacteria isolated on MRS+ agar, while those of enterococci andstreptococci were decreased. Resveratrol could, therefore, positively affectthe gut microflora by having a favourable effect on Lactobacillus- andBifidobacterium-populations.MDP006Detection and Characterization of Rotavirus Genotypes(VP4) by RNA Electrophoretic Patterns and Phylogeneticanalysis among children with acute gastroenteritis inTehran-IranS. Eskandarian*, S. Modarres Gilani, R. Edalat, A. SohrabiPasteur Institute, Virology Department, Tehran, IranIntroduction: Acute gastroenteritis has been established as the major publichealth problem in worldwide children. Rotavirus is the most importantetiological agent of gastroenteritis among children, It is also major cause ofchildren malnutrition. Rotavirus,which is a member of the reoviridae family, has a genome 11 dsRNA segment that are enclosed in a triple- layeredcapsid. Rotaviruses are classified into G-type and P- type. Therefore,determining the prevalent and types of rotaviruses within region is essentialto prepare for introducing a vaccine. Objectives: The genotype diversity ofgroup A human Rotavirus and phylogenetic analysis of P-type detected byMultiplex RT-PCR and DNA- Sequencing. Material and Method: A total of285 stool specimens were collected from children with diarrhea admitted totwo pediatric hospitals between 2008 and 2010 in Tehran-Iran.Polyacrylamide gel electrophoresis (PAGE) was used for isolating positiverotavirus Stool samples and they were genotyped by Multiplex RT-PCRmethod. P-genotypes of rotavirus isolated were sequenced. Result: Wefound relatively high prevalence rate of rotavirus gastroenteritis in children.29.1% stool specimens were positive .P [8] (81.92%) was the dominant ofgenotype, followed by P [4] (8.4%) , P [6] (7.2%) and mix type (2.4%). Thepeak of incidence was in the winter. A few sequence of P-genotypes strainsisolated showed high level of similarity to strains from other Asiancountries. Conclusion: we reported the VP4 genotype of rotaviruses -associated childhood diarrhea with high prevalence of P [8] genotype.Rotavirus strain surveillance programs are important for future vaccineformulation in Iran. Keywords: Human Rotavirus; VP4; Gastroenteritis;GenotypeMDP007Investigating the diversity of endosymbiotic bacteria inthe gills of the wood-boring bivalve Teredo navalisS. Heiden* 1 , S. Wetzel 2 , R. Sietmann 3 , N. Dubilier 2 , S. Markert 4 ,T. Schweder 11 Institute of Pharmacy, Ernst-Moritz-Arndt-University, Greifswald,Germany2 Max Planck Institute for Marine Microbiology, Symbiosis Group, Bremen,Germany3 Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald,Germany4 Institute of Marine Biotechnology, Greifswald, GermanyThe shipworms (Teredinidae) are a family of wood-boring bivalves thatharbor endosymbiotic bacteria in specialized cells (bacteriocytes) insidetheir gills. These symbionts are capable of digesting cellulose and of fixingmolecular nitrogen under microaerobic conditions. They are thussupplementing the nutrition of their eukaryotic hosts and allow them to usewood as a primary food source.In this work, the diversity of the endosymbiotic population in the gills of thewood-boring bivalve Teredo navalis Linnaeus, 1758, also known as thecommon shipworm, was analyzed. Four single-specimen 16S rDNA clonelibraries with specimens from two different locations in the western BalticSea (Möltenort Harbor, Eckernförde Harbor) were created. Sequences werealigned considering secondary structure of the small subunit (SSU) rRNAmolecule. The comparative sequence analysis was based on 1323unambiguous sites. The phylogenetic inference using a MaximumLikelihood-based approach revealed a high diversity of closely relatedbacteria. However, these showed significant evolutionary distance toendosymbionts found in other host species like Lyrodus pedicellatus deQuatrefages, 1849 [1, 3].Additionally, two bacterial strains (designated TN1023 and TN10130) wereisolated from the gills of single specimens and partially characterized.Comparative sequence analysis of the SSU rRNA gene suggested closerelationship to other strains of the culturable shipworm symbiontTeredinibacter turnerae, which have been described in the past [2].Characterization by scanning electron microscopy, however, showed that atleast one of these isolates (TN10130), in contrast to Teredinibacter turnerae,might be peritrichously flagellated.[1] Distel, D.L. et al (2002): Coexistence of Multiple Proteobacterial Endosymbionts in the Gills ofthe Wood-Boring Bivalve Lyrodus pedicellatus (Bivalvia: Teredinidae). Appl. Environ. Microbiol.,68, 6292-6299. Available at: http://dx.doi.org/10.1128/AEM.68.12.6292-6299.2002.[2] Distel, D.L. et al (2002): Teredinibacter turnerae gen. nov., sp. nov., a dinitrogen-fixing,cellulolytic, endosymbiotic gamma-proteobacterium isolated from the gills of wood-boring molluscs(Bivalvia: Teredinidae). Int J Syst Evol Microbiol, 52, 2261-2269. Available at:http://dx.doi.org/10.1099/ijs.0.02184-0.[3] Luyten, Y.A. et al (2006): Extensive Variation in Intracellular Symbiont Community Compositionamong Members of a Single Population of the Wood-Boring Bivalve Lyrodus pedicellatus (Bivalvia:Teredinidae). Appl. Environ. Microbiol., 72, 412-417. Available at:http://dx.doi.org/10.1128/AEM.72.1.412-417.2006.MDP008Investigation into the effect of growth stages on therhizospheric microbial community of rice plantsB. Breidenbach*, J. Pump, M.G. DumontDepartment of Biogeochemistry, Max Planck Institute for TerrestrialMicrobiology, Marburg, GermanyPlants excrete diverse compounds into the soil, a process collectively knownas rhizodeposition. Rhizodeposition forms the sole environment in the soil(rhizosphere) that is associated with a specific microbial community. Riceplants pass through several growth stages: the vegetative, reproductive andripening stage. Microbial growth in the rhizosphere is stimulated by thecontinual input of readily assimilable organic substrates from the root. Wehypothesize that changes in the plant growth and associated changes in rootspektrum | Tagungsband 2011