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

234[1991]. We were able to demonstrate that solute-induced proteinstabilization does not always correlate with ribosome stabilization.Furthermore, depending on the solute, we observed different effects inrelation to the subunits (30S and 50S) as compared to the fully functional70S ribosome.Gaucher EA, Govindrajan S & Ganesh OK (2008) Nature. 451:704-708Lambert D & Draper DE (2007) J Mol Biol. 370:993-1005Lee J & Kaletunç G (2002) Appl Env Microbiol. 68:5379-5386Mackey BM, Miles CA et al. (1991) J Gen Microbiol. 137:2361-2374SSP025Elucidation of potential vitrificants of Halomonas elongata DSM2581 T with regard to desiccation tolerance and bio-inspired use asinterface protectantsC. Tanne*, E.A. GalinskiUniversity of Bonn, Institute of Microbiology & Biotechnology, Bonn, GermanyThe loss of water is a general stress phenomenon for life on earth.However, some extremophilic organisms are able to survive almostcomplete desiccation by vitrification, a process termed anhydrobiosis orcryptobiosis. Under these conditions the whole metabolism is arrested andthe cells can remain dormant for a long period of time until they arerehydrated. This survival mechanism preserves macromolecules (e.g.proteins, DNA, membranes) by the formation of biological glasses at thenano-structured interface to the environment. Well-known glass-formingsubstances (sugars and other hydroxyl-group carrying compounds) arebelieved to replace water molecules in the hydration shell of biologicalboundaries and thus prevent complete inactivation by the lack of water.The present work aimed at the identification of such glass-formingcompounds in Halomonas elongata and other factors involved invitrification. Molecular candidates are hydroxylated derivatives of ectoine(S,S-beta-hydroxectoine), highly hydrophilic and intrinsically unstructuredproteins (so-called hydrophilins), but also inorganic ions and salts oforganic acids [1-4]. As an experimental approach to elucidate theorganism´s response to a forthcoming dehydration event the exponentiallygrowing culture was exposed to gradually increasing temperature beyondmaximum. In addition, bioinformatic data were exploited to predictpotential hydrophilins and to investigate other characteristics of theHalomonas elongata proteome.It was shown that, besides the expected accumulation of hydroxylatedforms of compatible solutes, H. elongata is also able to express so-calledhydrophilins to support vitrification. In addition, its moderately acidicproteome may provide an additional basis for increased water stresstolerance.Detailed understanding of all factors involved in vitrification andpreservation of biological surfaces which depend on water for function andintegrity will ultimately enable us to apply such knowledge for the longtermstabilization of immobilised enzymes and biohybrid interfaces as forexample in technical biosensors.[1] J.J. Caramelo, N.D. Iusem. When cells lose water: Lessons from biophysics and molecular biology.Progress in Biophysics and Molecular Biology 99(1):1-6. 2009[2] A. Kriško, Z. Smole, G. Debret, N. Nikolic, M. Radman. (2010).Unstructured hydrophilic sequences inprokaryotic proteomes correlate with dehydration tolerance and host association. Journal of MolecularBiology 402(5):775-82.[3] J. Buitink, I.J. van den Dries, F.A. Hoekstra, M. Alberda, M.A. Hemminga (2000). High criticaltemperature above Tg may contribute to the stablity of biological systems. Biophysical Journal 79(2): 1119-1128.[4] U.S. Patent 6,653,062SSP026The CRISPR/Cas system of Haloferax volcanii: requirements forthe defenceS. FischerUniversität Ulm, Biologie II, Ulm, GermanyThe CRISPR/Cas system is a prokaryotic defence system that providesadaptive and heritable immunity against foreign genetic elements in mostArchaea and many Bacteria. This system is widespread and diverse, but asit was only recently discovered, the precise molecular details for thedefence directed against invading plasmids or viruses are far fromunderstood. Clustered regularly interspaced short palindromic repeats(CRISPRs) together with CRISPR associated genes (casgenes) build thebasis of the system. The so-called spacer sequences in a CRISPR locus arederived from the invading nucleic acids (protospacer) in the adaptationstage, to enable recognition and degradation in case of re-infection(interference stage). Furthermore, specific short sequences called PAMs(protospacer adjacent motifs) are essential for the adaptation andinterference of most CRISPR/Cas types. We investigate the mechanisms ofthe CRISPR/Cas-mediated defence in the Euryarchaeon Haloferaxvolcanii- an organism for which the origin of spacer sequences remainstotally elusive and thus the role and identity of PAM sequences wasunknown until now. Using a plasmid assay for which a protospaceridentical to the first spacer of oneH. volcaniiCRISPR locus is combinedwith all potential 2 nt- or 3 nt-PAM sequences, we identified two PAMsequences so far. We further investigate, to which extent sequence identitybetween spacer and protospacer must be given to ensure a successfulinterference reaction.SSP027Succession patterns of distinct flavobacterial groups afterspring algal blooms in the North SeaC. Bennke* 1 , B. Fuchs 1 , A. Klindworth 2 , F.O. Glöckner 2 , G. Gerdts 3 ,A. Wichels 3 , K. Wiltshire 3 , M. Zeder 1,4 , R. Amann 11 MPI-für Marine Mikrobiologie, Molekulare Ökologie, Bremen, Germany2 MPI-für Marine Mikrobiologie, Microbial Genomic Group, Bremen, Germany3 AWI, Mikrobielle Ökologie, Helgoland, Germany4 Technobiology GmbH, Buchrain, SwitzerlandAlgae blooms are known to cause significant changes in bacterioplanktoncomposition. During and after the algal spring bloom in 2009 a largemicrobial community shift was observed in the North Sea. 16S rRNA tagsequencing at different timepoints revealed that Alphaproteobacteria andGammaproteobacteria as well as the Bacteroidetes, here in particular theclass Flavobacteria, dominate the bacterioplankton community in theNorth Sea at Helgoland Roads. In this study we dissected theflavobacterial response on algal blooms. Specific oligonucleotide probesfor Flavobacteria clades were designed, and these clades were quantifiedby catalyzed reporter deposition-fluorescence in situ hybridization(CARD-FISH) and automated microscopy.In spring 2009 a tight succession of distinct Flavobacteria clades wasobserved. Members of the genera Ulvibacter and Formosa reached relativeabundances of up to 20% and 24%, respectively, within one to two weeksafter the peak of the algal bloom. These groups seem to respond to specificsubstrates released by the algae after the bloom (bottom-up effect). Later,while Ulvibacter and Formosa subgroups dropped the Polaribacter cladeincreased up to 27% of the entire microbial community. Interestingly, allanalysed subgroups were present throughout the rest of the year 2009 onlyin low abundances, except for the Polaribacter clade which showedseveral peaks during the course of the year in response to the summer andautumn algal blooms. All flavobacterial subgroups responded morestrongly to the diatom-dominated spring bloom than to the autumn bloomcomposed mainly of green algae.In 2010 the spring phytoplankton bloom occurred one month later than in2009, but a similar succession of the flavobacterial groups could beobserved reaching similar cell numbers. Our findings suggest that the waxand wane of specific bacterioplankton clades might be an annuallyrecurring phenomenon in the North Sea, and therefore rather adeterministic than stochastic process.SSP028Host- and cell type-specific adhesion of human and animalEscherichia coli in association to their virulence-associated genesU. Frömmel* 1 , S. Rödiger 1 , A. Böhm 1 , J. Nitschke 1 , J. Weinreich 1 , J. Groß 1 ,O. Zinke 2 , H. Ansorge 3 , P. Klemm 4 , W. Lehmen 5 , S. Vogel 6 , T. Wex 7 ,C. Schröder 1 , P. Schierack 11 Hochschule Lausitz (FH) , FB Bio-, Chemie- und Verfahrenstechnik; AGMolekularbiologie, Senftenberg, Germany2 Museum der Westlausitz, Kamenz, Germany3 Senckenberg Museum für Naturkunde, Görlitz, Germany4 Technical University of Denmark, Lyngby, Denmark5 Attomol GmbH, Bronkow, Germany6 Lausitzer Seenland Klinikum GmbH, Hoyerswerda, Germany7 Otto-von-Guericke Universitiy, Magdeburg, GermanyEscherichia coli (E. coli) is a common bacterium of the intestinalmicroflora of mammals and birds but also can cause intestinal as well asextraintestinal disease. Pathogenic E. coli can be grouped into severalpathovars including host-specific and zoonotic bacteria.Successful colonization and infection of epithelial cells depend on initialadhesion which is mediated by fimbriae and other adhesins or colonizationfactors. Adhesins promote host- and tissue specificity or enable bacteria tocolonize a broader range of hosts and tissues which are two differentsurvival strategies.We sampled 410 pathogenic and commensal E. coli isolates from humansand 19 mammalian and avian species including domestic and wild animalsand including isolates from faeces and the urinary tract.All strains were tested for hemolysis on blood agar plates and for 42virulence-associated genes (VAGs) including several adhesins with aVideoScan Multiplex-PCR-Bead-Assay which was developed in ourlaboratory. All non-hemolytic isolates (n= 296) were analyzed foradhesion to four epithelial cell lines (Caco2: human intestinal, 5637:human urinary bladder, IPEC-J2: porcine intestinal, PK15: porcine kidney)automatically with our new developed VideoScan technology. Adhesionpattern were correlated with the presence of VAGs and VAG pattern.In average, hemolytic isolates carried twice as many VAGs compared tonon-hemolytic isolates. Isolates had a species-specific repertoire of VAGs.Adhesion pattern strongly varied between isolates independent fromspecies origin. Adhesion of bacteria could be divided into non-adherent,BIOspektrum | Tagungsband 2012