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

75corrosion inhibitors in dishwashing detergents and in deicing or anti-icingfluids on airplanes. Due to their widespread usage in many applications,their high polarity and therefore good water solubility on one hand andtheir poor biodegradability on the other, these compounds are found innearly all aquatic compartments including ground water. For that reasonthere is urgent need to shed more light on the biological relevance ofbenzotriazole derivatives. The aim of the present work is to gain insightinto selected BT derivatives biodegradation patterns by bench scale testswith three different activated sludge biocoenoses derived from threewastewater treatment systems: WWTP 1 with membrane technology,WWTP 2 equipped with a two-step activated sludge treatment and WWTP3 with an intermittent nitrification/denitrification regime. After inoculationwith 5 g L -1 MLSS and 10 mg L -1 of BT or else a 10 mg L -1 mixture of 4-TTri and 5-TTri ( 40/60%) the reactors, ranging from 100 to 500 ml involume, were operated under different nutrient and biomass conditions toevaluate the best setup for aerobically degrading benzotriazole compounds.Biodegradation was shown best for 5-TTri followed by BT and worst for4-TTri in all reactors regardless which sludge was applied. Concerning thedegradation rate over time the sludge from WWTP 1 proved best, followedby WWTP 2 and 3. Also the concentration of nutrients and energy sourcessuch as C- and N-substrates proved to be important. Thus by dosing thebenzotriazoles as co-substrates together with an easily utilizable C- and N-source degradation turned out faster compared to reactors fedbenzotriazoles as sole C- and/or N-source. In addition to the laboratoryexperiments environmental water samples were collected to check theinfluence of WWT retention times on biodegradation. Moreover,benzotriazole concentrations in the receiving rivers were determined.These studies showed in all tested waters benzotriazoles to be found atconcentrations ranging from 0.50 to 31.0 g L -1 . WWTPs turned out toconstitute one major point source for benzotriazoles into the aquaticenvironment. Ongoing research is focusing on benzotriazole degradingorganisms' or communities' characterization at aerobic and anaerobicconditions and locating of possible intermediates or end-products.FBV1-FGNo abstract submitted!FBV2-FGThe carbon depletion response of Aspergillus niger duringsubmerged cultivation.B.M. Nitsche* 1 , T.R. Jrgensen 1,2 , V. Meyer 2,3 , A.F.J. Ram 1,21 Leiden University, Institute of Biotechnology, Leiden, Netherlands2 Kluyver Centre for Genomics of Industrial Fermentation, Delft, Netherlands3 Berlin University of Technology, Institute of Biotechnology, Berlin, GermanyBackground: Filamentous fungi experience carbon limitation in both theirnatural habitats and biotechnological operations. Compared to nutrient-richgrowth conditions, carbon limitation triggers dramatic changes affectingvirtually all cellular processes. Liberation of carbon from extra- andintracellular sources fueling fungal self-propagation can be considered astheir key response. Comprehensive description of the processes involvedand their interactions are important to gain further understanding on asystems-level. Increasing knowledge will be relevant for industrial,medical and fundamental research to improve yields of bioprocesses anddevelop new antifungal strategies.Results: This study describes the physiological, morphological andgenome-wide transcriptional changes caused by severe carbon limitationduring prolonged submerged batch cultivation of the filamentous fungusAspergillus niger. The application of bioreactors allowed for highlyreproducible cultivation conditions and monitoring of physiologicalparameters. We describe the dispersed hyphal morphology at distinctcultivation phases and applied automated image analysis to illustrate thedynamics of cryptically re-growing hyphae. Using the AffymetrixGeneChip platform, we established genome-wide transcriptional profilesfor day 1, 3 and 6 of carbon limitation. Compared to exponential growthconditions, roughly 50% (7292) of all genes were differentially expressedduring at least one of the starvation time points. To identify majortranscriptional trends, we performed enrichment analysis of GeneOntology, Pfam domain and Kyoto Encyclopedia of Genes and Genomespathway annotations. Among the predominantly induced processes areautophagy and asexual reproduction. Furthermore, we discuss thetranscriptional profiles of enzyme classes, which have been reported toplay important roles in aging cultures of filamentous fungi, such aschitinases, glucanases and proteases.Conclusions: Using an interdisciplinary approach, which combines highlyreproducible cultivation conditions with bioinformatics includingautomated image analysis, genome-wide transcriptional profiling andenrichment analysis, this study provides the first comprehensive analysisof the carbon depletion response in filamentous fungi. The generated datawill be fundamental to further improve our understanding of interrelatedprocesses triggered by carbon limitation such as autolysis, proteolysis, celldeath, and reproduction.FBV3-FGBlood is a very special fluid - the transcriptome of Aspergillusfumigatus in response to human bloodP. Olbermann* 1 , S. Tarazona 2 , H. Irmer 3 , C. Jöchl 4 , D. Turras 5 , A. Di Pietro 5 ,H. Haas 4 , G.H. Braus 3 , A. Conesa 2 , S. Krappmann 11 Universität Würzburg, Zentrum für Infektionsforschung, Würzburg, Germany2 Centro de Investigacion Príncipe Felipe, Bioinformatics and GenomicsDepartment, Valencia, Spain3 University of Göttingen, Institute for Microbiology and Genetics, Göttingen,Germany4 Innsbruck Medical University, Division of Molecular Biology, Innsbruck,Australia5 University of Cordoba, Department of Genetics, Cordoba, SpainAspergillus fumigatus is the major cause of Invasive Aspergillosis (IA), alife threatening disease with a mortality rate of 90 to 95 % that affectsprimarily immunocompromised individuals. A pivotal step linked toseverity of this disease is the entry of the fungus into a blood vessel and itsdissemination into the blood circuit. Upon entering the blood stream A.fumigatus has to adapt to its new environment and to cope with multiplefactors. Although transcriptomes of several host infecting fungi have beenpublished recently, knowledge about the adaptation of the A. fumigatustranscriptome to blood environment inside the human host is scarce andlimits understanding of pathogenesis and A. fumigatus dissemination.To gain insight into this part of infection and transcriptional networksinvolved in this process, we developed an in vitro model using humanblood mimicking haematogenous dissemination including a time courseanalysis to elucidate the differences of fungal response at several timepoints towards blood. This model was used to capture the gene expressionthat can be found during adaptational processes of the fungus. Sampleswere analysed by whole genome expression profiling using microarraysfollowed by gene enrichment analysis and further bioinformatic analysis.Herewith we could identify multiple genes involved in adaptation of A.fumigatus to blood such as genes involved in signaling, growth regulationand metabolism. As a first application of our in vitro model we alsomeasured the transcriptional response of A. fumigatus to human bloodwhen exposed to the antifungal posaconazole. This gave us the possibilityto identify the responses of the fungus when coping with the drug in theenvironment in which it acts in human treatment. Additionally those datawere confirmed using real-time qPCR to support the role of certain genesfor the survival of A. fumigatus in blood.This analysis will provide important insights regarding the genes involvedin stages of IA and thus may lead the way to new targets for fighting thisopportunistic pathogen. The model allows us to test the role of A.fumigatus and factors affecting the pathogen in this unique environment.FBV4-FGProteomic profiling of the short-term response of Aspergillusfumigatus to hypoxic growth conditionsK. Kroll* 1,2 , M. Vödisch 1,2 , M. Roth 3 , A.A. Brakhage 1,2 , O. Kniemeyer 1,21 Hans-Knöll-Institute, Department of Molecular and AppliedMicrobiology, Jena, Germany2 Friedrich-Schiller-University Jena, Jena, Germany3 Hans-Knöll-Institute, Department of Bio Pilot Plant, Leibniz Institute forNatural Product Research and Infection Biology, Jena, GermanyAspergillus fumigatus is an opportunistic airborne pathogen causingsystemic infections in immunocompromised patients. This filamentousfungus is an obligate aerobe and requires molecular oxygen for growth.However, during the infection process A. fumigatus has to adapt quickly tovery low oxygen concentrations when it grows in inflammatory, necrotictissue. Recently, it was shown that hypoxia is involved in virulence of A.fumigatus [1]. In our lab, the metabolic long-term response of this fungushas recently been analyzed by using an oxygen-controlled chemostat [2].However, little is known about the short-term adaptive mechanisms of A.fumigatus to low oxygen concentrations. Therefore, we aimed toinvestigate the immediate response of A. fumigatus after oxygen depletionon the protein level.A. fumigatus was cultivated as a batch culture in a 3 L bioreactor. Afterpre-cultivation at 21 % (vol/vol) molecular oxygen concentration, theoxygen supply was shifted to 0.2 % (vol/vol) and several samples weretaken during a 24 hour period of hypoxia. Cytosolic protein levels wereanalyzed by 2D - gel electrophoresis and differentially regulated proteinswere identified by MALDI-TOF/TOF-analysis.Significant changes in the amino acid, carbohydrate and energymetabolism were observed within 24 hours of hypoxia. Glycolyticenzymes and proteins involved in amino acid metabolism were upregulated.Furthermore, there was an increased production of proteinsinvolved in respiration, electron transport and the general stress response.By contrast, proteins of the pentose phosphate pathway (PPP) and the TCAcycle were down regulated during the short-term response, as well.Under hypoxic conditions, we determined a strong up-regulation of thealcohol dehydrogenase AlcA which is involved in the utilization of ethanolBIOspektrum | Tagungsband 2012