TY - JOUR A1 - Schwibbert, Karin A1 - Marin-Sanguino, A. A1 - Bagyan, I. A1 - Heidrich, Gabriele A1 - Lentzen, G. A1 - Seitz, H. A1 - Rampp, M. A1 - Schuster, S.C. A1 - Klenk, H.-P. A1 - Pfeiffer, F. A1 - Oesterheit, D. A1 - Kunte, Hans-Jörg T1 - A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581T N2 - The halophilic γ-proteobacterium Halomonas elongata DSM 2581T thrives at high salinity by synthesizing and accumulating the compatible solute ectoine. Ectoine levels are highly regulated according to external salt levels but the overall picture of its metabolism and control is not well understood. Apart from its critical role in cell adaptation to halophilic environments, ectoine can be used as a stabilizer for enzymes and as a cell protectant in skin and health care applications and is thus produced annually on a scale of tons in an industrial process using H. elongata as producer strain. This paper presents the complete genome sequence of H. elongata (4 061 296 bp) and includes experiments and analysis identifying and characterizing the entire ectoine metabolism, including a newly discovered pathway for ectoine degradation and its cyclic connection to ectoine synthesis. The degradation of ectoine (doe) proceeds via hydrolysis of ectoine (DoeA) to Nα-acetyl-L-2,4-diaminobutyric acid, followed by deacetylation to diaminobutyric acid (DoeB). In H. elongata, diaminobutyric acid can either flow off to aspartate or re-enter the ectoine synthesis pathway, forming a cycle of ectoine synthesis and degradation. Genome comparison revealed that the ectoine degradation pathway exists predominantly in non-halophilic bacteria unable to synthesize ectoine. Based on the resulting genetic and biochemical data, a metabolic flux model of ectoine metabolism was derived that can be used to understand the way H. elongata survives under varying salt stresses and that provides a basis for a model-driven improvement of industrial ectoine production. KW - Genom KW - Ectoin KW - Biotechnologie KW - Halophile Bakterien PY - 2011 U6 - https://doi.org/10.1111/j.1462-2920.2010.02336.x SN - 1462-2912 SN - 1462-2920 VL - 13 IS - 8 SP - 1973 EP - 1994 PB - Blackwell Science CY - Oxford AN - OPUS4-22344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shirakawa, M.A. A1 - Zilles, R. A1 - Mocelin, A. A1 - Gaylarde, C.C. A1 - Gorbushina, Anna A1 - Heidrich, Gabriele A1 - Giudice, M.C. A1 - Del Negro, G.M.B. A1 - John, V.M. T1 - Microbial colonization affects the efficiency of photovoltaic panels in a tropical environment N2 - Sub-aerial biofilm (SAB) development on solar panels was studied in São Paulo. After 6, 12 and 18 months' exposure, photovoltaic panels were covered by increasing proportions of organic matter (42%, 53% and 58%, respectively). Fungi were an important component of these biofilms; very few phototrophs were found. Major microorganisms detected were melanised meristematic ascomycetes and pigmented bacterial genera Arthrobacter and Tetracoccus. While diverse algae, cyanobacteria and bacteria were identified in biofilms at 6 and 12 months, diversity at a later stage was reduced to that typical for SAB: the only fungal group detected in 18 month biofilm was the meristematic Dothideomycetes and the only phototrophs Ulothrix and Chlorella. Photovoltaic modules showed significant power reductions after 6, 12 (both 7%) and 18 (11%) months. The lack of difference in power reduction between 6 and 12 months reflects the dual nature of soiling, which can result from the deposition of particulates as well as from SAB fouling. Although 12-month old SAB demonstrated an almost 10-fold increase in fungal colonization and a higher organic content, the larger non-microbial particles (above 10 µm), which were important for efficiency reduction of lightly-biofilmed panels, were removed by high rainfall just before the 12-month sampling. KW - Sub-aerial biofilms KW - Energy production KW - Phototrophs KW - Fungi KW - Solar panels KW - Fouling KW - Biofilms KW - Photovoltaic module PY - 2015 U6 - https://doi.org/10.1016/j.jenvman.2015.03.050 SN - 0301-4797 SN - 1095-8630 VL - 157 SP - 160 EP - 167 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franziska, Pietsch A1 - Nordholt, Niclas A1 - Heidrich, Gabriele A1 - Schreiber, Frank T1 - Prevalent Synergy and Antagonism Among Antibiotics and Biocides in Pseudomonas aeruginosa N2 - Antimicrobials can exert specific physiological effects when used in combination that are different from those when applied alone. While combination effects have been extensively mapped for antibiotic-antibiotic combinations, the combination effects of antibiotics with antimicrobials used as biocides or antiseptics have not been systematically investigated. Here, we investigated the effects of combinations of antibiotics (meropenem, gentamicin, and ciprofloxacin) and substances used as biocides or antiseptics [octenidine, benzalkonium chloride, cetrimonium bromide, chlorhexidine, Povidone-iodine, silver nitrate (AgNO3), and Ag-nanoparticles] on the planktonic growth rate of Pseudomonas aeruginosa. Combination effects were investigated in growth experiments in microtiter plates at different concentrations and the Bliss interaction scores were calculated. Among the 21 screened combinations, we find prevalent combination effects with synergy occurring six times and antagonism occurring 10 times. The effects are specific to the antibiotic-biocide combination with meropenem showing a tendency for antagonism with biocides (6 of 7), while gentamicin has a tendency for synergy (5 of 7). In conclusion, antibiotics and biocides or antiseptics exert physiological combination effects on the pathogen P. aeruginosa. These effects have consequences for the efficacy of both types of substances and potentially for the selection of antimicrobial resistant strains in clinical applications with combined exposure (e.g., wound care and coated biomaterials). KW - Synergy KW - Antagonism KW - Suppression KW - Biocides KW - Antibiotics KW - Pseudomonas aeruginosa PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-520845 VL - 11 SP - Article 615618 PB - Frontiers CY - Lausanne AN - OPUS4-52084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -