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

FMP013Differentiation of Microorganisms Associated with Wineby DNA-fingerprinting analysisK. Wirth 1 , A. Petri 1 , P. Sebastian 1 , V. Blättel* 1 , J. Pfannebecker 2,1 ,J. Fröhlich 3,1 , H. König 11 Institute of Microbiology and Wine Research, Johannes-Gutenberg-University, Mainz, Germany2 Life Science Technologies, Microbiology, University of Applied Sciences,Lemgo, Germany3 Erbslöh Geisenheim AG, Geisenheim, GermanyThe conversion of must into wine is a complex microbiological process inwhich various yeasts and bacteria could be involved. Due to the negativeinfluences of some metabolic compounds of several of these organisms,methods for rapid identification of these species are required. In the earlystages of wine making, if the must is exposed to oxygen, acetic acid bacteriaare able to generate high amounts of acetic acid, which can lead to spoilageof the wine. Mainly, lactic acid bacteria are responsible for the formation ofdiacetyl, biogenic amines, mousy off-flavour and exopolysaccharide slimes.In this case some molecular methods for the identification of bacteria like16S rDNA sequencing are often less specific because of the highconservation of this gene within these genera. For further classificationseveral time consuming physiological tests would be needed. With regard tothe determination of yeasts the ITS region is often insufficient for theidentification of wine related yeast species. Especially, the differentiation ofthe Saccharomyces sensu stricto group, including the wine-relevant speciesSaccharomyces cerevisiae, Saccharomyces bayanus and Saccharomycesparadoxus is not possible.For a better monitoring of the vinification process identification of winerelated microorganisms is essential. Therefore, we applied a DNAfingerprintingmethod based on the specific amplification of certain genomicregions which are flanked by the NotI recognition site (Nested SpecificallyAmplified Polymorphic DNA-PCR, nSAPD-PCR) for the classification ofwine-related lactic acid bacteria, acetic acid bacteria, Sclerotinia/Botrytis,Dekkera/Brettanomyces, and Saccharomyces species.FMP014Cleaning and disinfection of work shoes from the field ofPPEM. Würtz* 1 , L. Vossebein 21 Microbiological Testing and Research, PFI Biotechnology e.V., Pirmasens,Germany2 wfk Cleaning Technology Institute, Krefeld, GermanyIn many industrial branches, including food, pharmaceutical and cosmeticindustry, hygiene demands are increasing. Although personal protectiveequipment (PPE) includes shoes as well as other clothing that need to bechanged, cleaned or disinfected frequently, hygienic demands for shoes wereoften neglected in the past. Classical, water-based cleaning and disinfectionmethods damage the footwear, protective properties or do not yield insatisfactory disinfection.wfk and PFI have developed together a cleaning and disinfection procedurefor work shoes from the field of personal protective equipment based on aliquid CO 2-cleaning method, which allowsgentle but disinfecting cleaningand preserves required safety and protective functions of this footwear afterseveral reprocessing cycles.Specifications have been worked out for safety and protective shoes suitablefor a disinfecting CO 2-cleaning procedure.In a liquid CO 2 treatment shoes are not moistened - no drying is required.Inactivation of pathogens in liquid CO 2 depends on the species, theincubation time, water content and the presence of additives.FMP015Raman spectroscopic detection of meat spoilage byPseudomonas putidaH. Schricker 1 , R. Scheier 1 , F. Meussdoerffer 1 , O. Meyer 2 , H. Schmidt* 11 Research Center for Food Quality (ForN), University of Bayreuth,Kulmbach, Germany2 Department of Ecological Microbiology, University of Bayreuth, Bayreuth,Germanyapplied even to samples wrapped with standard packaging materials ifvisible or near-infrared excitation lasers are applied [1].We have demonstrated recently that the spoilage status of meat can beappraised by means of multivariate statistical analysis of the Raman spectra[2]. For the further development of such analyses it is essential to distinguishbetween bacterial and non-bacterial induced alterations of the meat surfaceand of the spectra.Here, we report results of a study on pork meat which has been sterilized onthe surface to remove the natural flora and which was then artificiallyspoiled with Pseudomonas putida, a prevalent psychrophilic spoilagebacterium. Simultaneous measurements of bacterial growth andcorresponding Raman spectra were performed with three sets of meatsamples over a period of two weeks of storage at 4°C. These comprised: (i)uncontaminated meat as a control for sterility, (ii) meat which has beencontaminated on its surface with P. putida, and (iii) meat covered by amembrane with a pore size of 0.2 mm on which P. putida was spreaded.When the inoculated bacteria proliferating on the surface of the samplesentered the late exponential growth phase, they caused strong laser-inducedfluorescence (LIF) which was absent in the uncontaminated samples. Ourresults show how the Raman technology can be used to differentiatebetween the three model conditions. We also demonstrate that the microbialstatus of cold stored meat can be classified correctly and conveniently by thecorresponding Raman spectra.[1] A prototype hand-held Raman sensor for the in-situ characterization of meat quality HeinarSchmidt, Kay Sowoidnich, Heinz-Detlef KronfeldtApplied Spectroscopy, 64 (2010) 888-894.[2] Application of diode-Laser Raman spectroscopy for in situ investigation of meat spoilage KaySowoidnich, Heinar Schmidt, Martin Maiwald, Bernd Sumpf, Heinz-Detlef Kronfeldt FoodBioprocess Technol (2010) 3:878-882.FMP016A tool for rapid detection of old and new types ofStreptococcus thermophilus bacteriophages in dairiesH. Neve*, Y. Ali, N. Lüth, K.J. HellerDepartment of Microbiology and Biotechnology, Max Rubner Institute, Kiel,GermanyMany strains of Streptococcus thermophilus starter cultures are susceptibleto infection by lytic bacteriophages in dairies, e.g., during production ofyoghurt, mozzarella and Swiss-type cheeses. Phages of these thermophiliclactic acid bacteria have been isolated and characterized world-wide and arecurrently grouped into two distinct subgroups on basis of their phagestructural proteins and their mode of DNA packaging. The two groupscomprise either cos-type phages containing DNA with cohesive terminalends or pac-type phages revealing a „head-full” mechanism of DNApackaging. Representatives of both phage groups cannot be differentiatedmorphologically (Siphoviridae phages). For the simultaneous detection anddifferentiation of cos- und pac-type S. thermophilus phages, a PCR systemhas been established on basis of conserved DNA regions of the non-relatedgenes coding for the major head proteins (mhp) of both phage types. Thismultiplex PCR system can be used both for the detection of lytic phages inwhey and product samples and for the detection of prophages in lysogenic S.thermophilus cultures as well.When the multiplex PCR tool was tested with a broad set of lytic S.thermophilus phages, one phage failed to generate a PCR amplicon. Byelectron microscopy it was shown that this new phage differedmorphologically from all other well-known S. thermophilus phages. It isnotable that this new phage also exhibited a number of physiologicalcharacteristics unrelated to those of all other cos- or pac-type S.thermophilusphages.DNA sequence analysis of the major head gene region of the new phageindicated high DNA homology to the corresponding DNA region ofStreptococcus pyogenes phages. The standard multiplex-PCR forcomprehensive and reliable detection of S. thermophilus-phages wasupdated with a DNA primer pair specific for the mhp gene of the new phage.Infrared and Raman spectroscopy have been proven useful tools for rapidand non-invasive detection of meat spoilage. The Raman method can bespektrum | Tagungsband 2011