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

168biosurfactant. The putative lipopeptide has potential applications in thepetroleum industry and environmental bioremediation. Moreover, it couldbe used as an antimicrobial agent.1- Cameotra, S. S., Makkar, R. S., Kaur, J. and Mehta, S. K. (2010). Synthesis of Biosurfactants and theirAdvantages to Microorganisms and Mankind. Adv. Exp. Med. Biol. 672: 261-280.2- Mulligan, C.N.(2005). Environmental Applications of Biosurfactants. Environ. Poll.133: 183 198.3- Krishnaswamy, M., Subbuchettiar, G., Thiengungal, K. R., and Panchaksharam, S.(2008). Biosurfactants:Properties, Commercial Production and Application. Current Science. Rev.VOL. 94.OTP140A diagnostic qPCR assay for detection and quantification ofemetic and non-emetic Bacillus cereus in milkM. Dzieciol* 1 , M. Fricker 2 , M. Wagner 1 , I. Hein 1 , M. Ehling-Schulz 21 Institute for Milk Hygiene, Milk Technology and Food Science, Department forFarm Animals and Veterinary Public Health, Vienna, Austria2 Food Microbiology Unit, Department for Farm Animals and Veterinary PublicHealth Clinic for Ruminants, Vienna, AustriaQuestion: Bacillus cereus is known as the causative agent of an emeticand a diarrheal type of food-borne illness, and thus is a special problem forpublic health issues and for the dairy industry. Therefore more precisemonitoring of B. cereus is necessary for a better understanding of theircontribution to health and disease.Methods: The aim of the present study was to develop a diagnostic realtimequantitative PCR (qPCR) for the B. cereus group in milk. A TaqManqPCR assay based on amplification of the gyrase B (gyrB), the ces emetictoxin and the 16S rRNA target sequences was designed including aninternal amplification control (IAC) to identify false negative results.Results: The method showed 100% inclusivity and exclusivity whentesting a panel of 41 B. cereus group strains, 10 non-B. cereus groupstrains and 17 non-bacilli strains. The IAC target included in each qPCRreaction showed no interference with the main reaction. The detection limitwas successfully established in artificially contaminated raw milk samplesand the optimized assay applied to naturally milk contaminated samples.Conclusions: The qPCR assay is specific and sensitive and provides anefficient diagnostic and monitoring tool for the identification of the B.cereus group in food.OTP141ROS formation by photochemical reactions affect BCC in ahumic lake and induce adaptive responses in abundant bacteriaS. Glaeser* 1 , H.-P. Grossart 2 , J. Glaeser 31 Justus Liebig Universität, Institut für Angewandte Mikrobiologie, Gießen,Germany2 Institut für Gewässerökologie und Binnenfischerei, Limnologie GeschiteterSeen, Stechlin, Germany3 Justus Liebig Universität, Mikrobiologie und Molekularbiologie, Gießen,GermanySunlight-mediated photochemical reactions of colored dissolved organicmatter (CDOM) is an important process in humic lakes enhancingsubstrate availability for heterotrophic bacterioplankton. Althoughbacterioplankton species benefit from generated carbon substrates theyhave to cope with toxic reactive oxygen species (ROS) generatedsimultaneously. We investigated effects of artificially increased singletoxygen ( 1 O 2) formation and hydrogen peroxide (H 2O 2) concentrations onbacterioplankton community composition (BCC) in the subsurface waterlayer of the humic Lake Grosse Fuchskuhle.BCC changes of abundant and metabolically active bacteria wereinvestigated by the generation of 16S rRNA gene clone libraries and 16SrRNA targeting RT-PCR DGGE analysis using Bacteria and groupspecificprimer-systems.Major bacterioplankton groups respond differently to 1 O 2 and H 2O 2exposure. Alphaproteobacteria (Novosphingobium acidiphilum) andBetaproteobacteria (Polynucleobacter necessarius and Limnohabitansrelated species) increased in relative abundance after 1 O 2 but not afterH 2O 2 exposure. In contrast freshwater Actinobacteria were not detectedafter 1 O 2 exposure but increased in relative abundance after H 2O 2exposure. We were able to isolate strains representing the abovementionedAlpha- and Betaproteobacteria and used those for laboratoryand in situ studies to investigate the response to ROS exposure. Firstexperiments showed that those strains were capable to withstand increased1 O 2 exposure after pre-incubation with moderate 1 O 2 concentrationsoccurring regularlyin the investigated ecosystem. Our results indicate thatROS generation by CDOM photolysis is an important factor for BCC inhumic lakes and favor species with adaptive response mechanisms to ROSexposure.Glaeser SP., Grossart, H.-P. , and J. Glaeser (2010) Environ Microbiol 12(12): 3124-36OTP142Gluconobacter oxydans as a platform for the production ofindustrially important productsP. Schweiger* 1 , H. Groß 2 , U. Deppenmeier 11 Universität Bonn, Institut für Mikrobiologie und Biotechnologie , Bonn,Germany2 Universität Bonn, Institute of Pharmaceutical Biology, Bonn, GermanyMany useful organic compounds, such as pharmaceuticals and foodadditives, contain asymmetric carbon centers and enantionmeric formsexist. Chemical synthesis of these products is often troublesome andproduces racemates. It is common to have a single biologically activeenantiomer, while the other does not show activity and sometimes has aharmful effect. In such cases chemically synthesized racemates usuallyneed to be resolved, especially for pharmaceuticals. In contrast, manyenzymes act regio- and stereoselectively and are naturally capable ofconverting pro-chiral educts to enantiopure products. Gluconobacteroxydans is an important organism in biotransformation (e.g used invinegar, vitamin C and antidiabetic drug production). Its genome isknown 1 and contains many uncharacterized cytosolic and membranebounddehydrogenases/oxidoreductases (>70) and they were surveyed fortheir ability to produce industrially important chiral products. Investigationinto protein function via heterologous gene production in E. coli revealedmany oxidoreductases that reduced ,-diketones, -ketoaldehydes, andvinyl ketones. These enzymes are capable of producing chiral buildingblocks that find uses in industry (e.g. pharmaceutical, food additives andfragrance). Four cytoplasmic oxidoreductases were capable for producinghydroxy carbonyls with chiral centers 2 . Additionally, three cytoplasmicreductases acted on the olefinic bonds of vinyl ketones, two of whichproduced stereospecific products when the olefinic bond was substituted 3 .A cofactor regeneration scheme was developed to decrease costs andincrease yields. Membrane-bound dehydrogenases do not need cofactorregeneration and those of G. oxydans are known to excrete theirincomplete oxidation products of sugars, polyols, and alcohols to almostquantitative yields into the medium. Accordingly, the numerousmembrane-bound dehydrogenases of G. oxydans were found to oxidize anarray of diols and polyols, likely to chiral hydroxy carbonyls.Identification of the enzymatic products is currently ongoing.Consequently, G. oxydans enzymes are renewable resources that provide aplatform for the production of optically active products in high amountsand avoid the toxicity often involved in multi-step organic synthesis.1Prust C, Hoffmeister M, Liesegang H, Wiezer A, Fricke WF, Ehrenreich A, Gottschalk G, Deppenmeier U(2005) Complete genome sequence of the acetic acid bacterium Gluconobacter oxydans. Nat Biotechnol.23(2):195-200.2 Schweiger P, Gross H, Deppenmeier U (2010) Characterization of two aldo-keto reductases fromGluconobacter oxydans 621H capable of regio- and stereoselective alpha-ketocarbonyl reduction. ApplMicrobiol Biotechnol. 87(4):1415-1426.3 Schweiger P, Gross H, Wesener S, Deppenmeier U (2008) Vinyl ketone reduction by three distinctGluconobacter oxydans 621H enzymes. Appl Microbiol Biotechnol. 80:955-1006.OTP143Microbial quality of table eggs sold in some Libyan marketM. Salem*, H. Elgheriani, A. Alfetory, S. ElmegerhiBioTechnology Research Center, Microbiology, Tripoli, Libyan ArabJamabiriyaHigh development in commercial poultry rearing in Libya play animportant role in the creation of income and also provide food in form ofmeats and eggs , in Libya consumption of eggs per person per week aboutsix eggs.The eggs considered to be highly nutritional value containing high levelsof vitamins and minerals, although the eggs considered a source ofcomplete food for growth but there are a lot of researches indicate thatmicro organisms often contaminate eggs.Total of 150 samples were collect randomly from different Libyan marketsin Tripoli area and area surround Tripoli.Total count of bacteria and fungi were performed to all samples.The result showed that there were high levels of bacteria Isolated fromeggs content in different percents,E.coliwas more frequency andpseudomonas spp were highly frequent and Aeromonas .sppOTP144Simple and Rapid Detection Of Salmonella spp from Cattlefarms using Polymerase Chain Reaction in Arak, IranS.D. Hosseini*, A. Jadidi, P. Jafari, A. HomayounimehrRazi, Molecular biology, Arak, Iran, Islamic Republic ofThis study goal to employ biochemical and molecular assays to detect anddiagnoseSalmonellain cattle farms in Markazi province in central part of Iran. Forthis reasone,1124 faecal samples were collected from cattle randomly.Selective culture media specific for Salmonella were used to grow anumber of colonies from cattle samples. Salmonella suspicious colonieswere confirmed using biochemical tests. After biochemical confirmation,the isolates were subjected to molecular based approach to identifyBIOspektrum | Tagungsband 2012