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

163dehydrogenases, indicating their important role within the oxidativemetabolism of ethylene glycol. This hypothesis was further supported by acorresponding double deletionmutant, which shows a strong decrease inethylene glycol metabolism.OTP118Subtyping off17- related genes in wastewater of slaughterhousesS. Elmegerhi 1,21 Biotechnology Research Center, Microbiology, Tripoli, Libyan ArabJamabiriya2 Libyan Arab JamabiriyaThe zoonotic pathogens ofE.colican survive over long periods in sewagesludge as well as on pasture land and in association water systems. Theycould be widely spread in the environment by direct land application ofsludge or by regular contamination of surface water, but limitedinformation is available concerning the spreading of these pathogens insewage of slaughterhouses. TheF17family includesF17a, F17b, F17c,F111fimbriae produced by bovineE.colistrains. Wastewater samples from12 slaughterhouses located in different regions inFrancewere tested todetect theF17-related fimbriae and to detect four subtypes of structuralsubunit genes positiveEscherichia coliisolates. A total of 224 wastewatersamples were collected in wastewater treatment plants at different stagesof wastewater processing in small and big abattoirs and down andupstream rivers, screened for the presence ofF17 genes(F17 a- A gene, F17b- A gene, F17c-A/gafA gene and F111-A gene) by multiplexPCR.F17positiveE. coliisolates were detected in 24 % of the samplescollected (54/224); F17 a- A gene were found in 18 %,F17 b- Agene in4%,F17c-A/gafAgene in 41% andF111-Agene in 37% of the samples in allslaughterhouses, respectively, suggesting that they could be spread into theenvironment. Our results suggest that the diversity of theE. coli-associatedvirulence factors in the strains indicates that the environment may play animportant role in the emergence of new pathogenicE. colistrains and toincrease our knowledge of the important prevention needed in ourenvironment from the pathogenicE. coliand their mutual correlation.Keywords: slaughterhouses- wastewater-multiplex PCR-F17 a- A gene,F17 b- A gene, F17c-A/gafA gene and F111-A gene.OTP119Identification of Lignin-degrading enzymes from bacteriaN. Staiger* 1 , S. Bartetzko 1 , T. Hirth 1,2 , S. Rupp 1 , S. Zibek 11 Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB,Stuttgart, Germany2 Universität Stuttgart, Institut für Grenzflächenverfahrenstechnik IGVT,Stuttgart, GermanyLignin is the most abundant renewable source of aromatics. [1] Therefore, itis an interesting natural source for aromatic compounds in chemicalsynthesis, glues or biobased materials. Lignin, together with Cellulose andHemicellulose, is part of the structural framework in plants. [2] There arehuge amounts of lignin available from straw, waste wood or by-productsfrom paper industry (~50 mio t/a). Nowadays around 98% are burned toproduce energy. A prerequisite for the efficient utilization of lignin as aresource for chemicals is an adequate depolymerization process to obtainaromatic monomers from the recalcitrant polymer structure. Severalenzymes have been shown to be involved in the enzymatic lignindegradation process, especially laccases (EC 1.10.3.2) and peroxidases(lignin peroxidase, EC 1.11.1.14 and manganese peroxidase,EC 1.11.1.13)from white-rot fungi. [3]Since the commercially available lignin-modifying enzymes (LMEs) fromfungi are too expensive for the use in industrial applications, we arefocussing on the identification and overproduction of LME from bacteria.To our knowledge, no lignin degrading enzymes from bacteria arecommercially available. We have identified seven bacterial strains withlignin-degrading potential from the literature and conducted cultivationexperiments to determine LME activity in the culture supernatants. Twomedia with or without lignin as inductor have been used. Our results showthat six strains grew in the culture media supplemented with 0.2% (w/v)lignin. Meanwhile one strain was able to grow with 0.1% (w/v) but notwith 0.2% (w/v) lignin. As expected, all of the strains were able to grow inthe standard media without lignin. In most of the bacteria a significantincrease in LME production was determined when supplemented withlignin. Currently, genomic libraries of selected bacteria out of these sevenstrains are constructed and LMEs will be identified applying highthroughputscreening (HTS) methods.[1] Wong, D. W. S. (2009) Structure and action mechanism of ligninolytic enzymes. Appl BiochemBiotechnol(157), 174-209.[2] Kuhad, R. C., Singh, A., Eriksson, K. E. (1997) Microorganisms and Enzymes Involved in theDegradation of Plant Fiber Cell Walls. Adv Biochem Eng Biotechnol.(57), 45-125.[3] Qi-He, C., Krügener, S., Hirth, T., Rupp, S., Zibek, S. (2011) Co-cultured production of ligninmodifyingenzymes with white-rot fungi. Appl Biochem Biotechnol.(165), 700-718.OTP120Beat the cold: Multiple roles of the RNA helicase CshA atlower temperatures in Bacillus subtilisM. Lehnik-Habrink*, L. Rempeters, J. StülkeUniversity of Göttingen, Dept. of General Microbiology, Göttingen, GermanyIn its natural habitat, the upper layers of the soil, Bacillus subtilis has tocope with a wide range of environmental challenges like low temperatures.Under these conditions the bacterium is faced with decreased membranefluidity and changes in the topology of the DNA. Furthermore, theformation of secondary structures of RNA is favored with decreasingtemperatures. To avoid undesirable intra- and intermolecular interactionsof RNA molecules, the cell encodes a variety of proteins helping the RNAto fold properly. One of the largest protein classes in RNA metabolism areDEAD-box RNA helicases. Such RNA helicases are highly conservedenzymes utilizing ATP to bind and remodel RNA or ribonucleoproteincomplexes.In this study we have investigated the impact of the DEAD-box RNAhelicase CshA on the growth of B. subtilis at low temperatures. We showthat under these conditions CshA is crucial for the bacterium to surviveand deletion of cshA leads to aberrant cell morphologies. Using a wide setof experiments we demonstrate that CshA is involved in the degradation ofmRNA, the proper assembly of ribosomes and interactions with proteins ofthe cold shock response. Taken together, the DEAD-box RNA helicaseCshA has multiple roles in the adaption process of the cell to lowertemperatures thereby dealing with rRNA and mRNA molecules.OTP121Conjugative plasmid pLS20 of Bacillus subtilis alters thetranscriptome and physiology of its host organismT. Rösch* 1,2 , W. Golman 1 , J. González Pastor 3 , P.L. Graumann 11 Faculty of Biology II, Albert Ludwigs University, Microbiology, Freiburg,Germany2 Spemann Graduate School of Biology and Medicine, Albert LudwigsUniversity, Freiburg, Germany3 Centro de Astrobiología (CSIC-INTA), Departamento de Ecología Molecular(Invernadero), Madrid, SpainBacillus subtilis strains from the environment harbor different plasmids,which have been shown to alter different physiological traits, such asbiofilm formation. Here we analyse in detail the effect of a largeconjugative plasmid found in B. subtilis isolate (natto) used for foodprocessing in Japan. Our work provides evidence that the plasmid pLS20induces a global change in gene regulation on the host chromosome, butmaintains and propagates itself without harmfully burdening the host.Exponentially growing cells exhibited numerous differences in theexpression of genes involved in the intermediary metabolism, cellenvelope, different cellular processes, stress resistance and motility.Several changes lead to a benefit for the fitness of the host to adapt toenvironmental changes, the observed reduction of motility may lead to abenefit for the plasmid for more efficient transfer between bacteria.Interestingly, plasmid pLS20 shows a significantly extended lag phasecompared to plasmid-free Bacillus cells, and conjugates most efficientlyduring the lag period between stationary phase and exponential growth.The later commencement of growth is accompanied by the induction oftransfer genes during this growth phase, while exponential growth leads toa reduction in transcription rates of conjugative proteins. Our work revealsa mutual benefit for host and conjugative plasmid and a differentiation-likebehavior of conjugative DNA transfer.OTP122Removal of pharmaceutical compound diclofenac by iron bacteriaH. Zhu*, W. Sun, Y. Zhang, U. Szewzyk, S.-U. GeissenTechnical University Berlin (TU Berlin), Environmental Microbiology, Berlin,GermanyIn recent years, pharmaceuticals are increasingly being detected in manywaterways all over the world. As a frequently prescribed non-steroidalanti-inflammatory drug, diclofenac has been ubiquitously detected in theinfluents and effluents of wastewater treatment plants (WWTPs) at the g/llevel, and it also occurs at concentrations of the ng/l level in surface water,ground water and even in drinking water. Although the acute ecotoxicityof diclofenac is relatively limited, it definitely poses a risk on theecosystems where it is present.Biotransformation is generally considered to be the main process by whichto remove pharmaceuticals, both in WWTPs and in aquatic environment.In many cases, microorganisms are applied to mineralize the pollutants towater or degrade them to acceptable forms. In this work, pure cultured ironbacteria were utilized to remove diclofenac. Meanwhile, the variousfactors that might affect the removal efficiency, such as initial diclofenacconcentration, residual Fe 2+ levels, and Mn content, were investigated.BIOspektrum | Tagungsband 2012