VAAM-Jahrestagung 2012 18.–21. März in Tübingen

25plant disease resistance against pathogenicmicro-organisms such as root rot producingfungi (Heterobasidion sp. on Norway spruce),seed decomposing fungi (Neofusicoccum sp.on Araucariaceae; co-operation with Brazilianand Australian research groups) as well asleaf pathogenic fungi (Alteranaria brassicicolaon Arabidopsis thaliana). We focus on bothmolecular responses of target organisms andbacterial and fungal effector molecules(collaboration with Hans-Peter Fiedler, IMIT)which contribute to the observed interactionpatterns.Prof. Dr. Ingo AutenriethIMIT, Department of MedicalMicrobiology and HygieneThe Department of Medical Microbiology andHygiene is involved in research, teaching ofstudents (human and dental medicine, molecularmedicine, biology etc.) and is runningthe infectious disease laboratory diagnosticunit of the University Hospital Tübingen.The question addressed by the variousresearch groups is how bacterial pathogens bymeans of virulence factors and how microbialproducts act on host cells and the hostimmune system, particularly how virulencefactors contribute to immune evasion.The research focus is host-microbe interactionsparticular at mucosal surfaces andthe role of the microbiota inmucosal immune responsesand inflammation. The aimis to unravel basic mechanismsof pathogenesis of bacterialinfections and bacteria-triggeredinflammatoryprocesses in order to understandthe principles of hostsusceptibility for and resistanceto infections, respectively,and in consequence tofind novel approaches oftherapeutic intervention. Theapproach includes mainlycellular microbiology andmolecular biology methodsSchütz); others address Staphylococcus infections(Weidenmaier, Wolz, Liese) and infectionsin cystic fibrosis patients (Döring). Furthermore,the role of commensal bacteria ofthe intestinal tract in intestinal immunehomeostasis, inflammatory bowel diseasesand susceptibility to gastrointestinal infectionsis under investigation (Frick).Prof. Dr. Andreas PeschelIMIT, Department of Cellular andMolecular Microbiology SectionAndreas Peschel’s lab investigates the biologyand pathogenicity of Staphylococcusaureus, a bacterial species capable of two profoundlydifferent life styles – as an unremarkableconstituent of the human nasalmicrobiota or as a major pathogen causingsevere disseminated infections along withhigh mortality. The processes governing thesuccessful colonization of the nose and subsequentinfection of sterile tissues representmajor topics of the lab’s four research teams.Cell wall teichoic acids, complex glycopolymersat the staphylococcal cell surface andtheir role in mediating adhesion to hostepithelial cells and lectins are in the focus ofGuoqing Xia’s team. Bernhard Krismer andcolleagues study the metabolic adaptation ofS. aureus to life in the nose and the staphylococcalinterference with competing microbes.as well as experimental animalinfection models.University Hospital, Department of Medical MicrobiologyWhile some of theresearch groups are working on the pathogenesisof Yersinia enterocolitica infectionsfocusing on the type three secretion systemand outer membrane proteins of Y. enterocolitica,and analyze how bacterial proteins affectthe host immune response, particularly dendriticcells (Autenrieth I., Autenrieth S., Bohn,The modulation of local and systemic inflammationby S. aureus peptide toxins, the ‘phenol-solublemodulins’, is investigated by theteam headed by Dorothee Kretschmer. Thefourth team (Christoph Ernst et al) exploreshow S. aureus copes with antimicrobial peptidesreleased by host leukocytes and epithelialcells and how the corresponding mechanismscontribute to S. aureus antibiotic resistance.Prof. Dr. Andreas KapplerCenter for Applied Geosciences,Department of GeomicrobiologyThe Geomicrobiology Group at the Center ofApplied Geosciences focuses on the interactionsof microorganisms and minerals in modernand ancient environments. Iron mineralslargely determine the fate of many nutrients(e.g. trace metals, phosphate) as well as theenvironmental behaviour of harmful(in)organic pollutants. Microbial Fe(II)-oxidizingand Fe(III)-reducing communities playa key role in iron-mineral formation and transformation.Studying both biological molecularmechanisms and geochemical conditions arecrucial to the identification, localization andquantification of these biogeochemicalprocesses. Therefore, together with the associatedjunior research groups of MolecularMicrobial Ecology (S. Behrens), Microsensorsand Biogeochemical Modelling (C. Schmidt)and the affiliated Emmy-Noether researchgroup for Analytical Microscopy (M. Obst),we combine microscopic, spectroscopic andmolecular techniques with geochemical analysisin order to understand modern and ancientiron biogeochemistry and its environmentalimpact. In more detail, ourprojects comprise i) biogeochemistryand molecularecology of microbial Fecycling, ii) physiology, genetics,high-resolution imagingand spectroscopic analysis ofmicrobial Fe(II) oxidationand Fe biomineralization, iii)microbial magnetite formation,iv) humic substances aselectron shuttles in biogeochemicalredox processes, v)mechanisms of depositionand diagenesis of Fe mineralsin Precambrian BandedIron Formations, vi) consequencesof microbial Fe(II)oxidation and Fe(III) reductionfor the environmentalfate of Cd and As in soil-plant-microbe systemsand in As drinking water filters, vii)microbial formation and degradation of halogenatedorganic compounds, viii) impact ofbiochar addition on soil microbial communitycomposition, microbial N-cycling and contaminanttransformation.BIOspektrum | Tagungsband 2012