@article{MitzscherlingMacLeanLipusetal.2022, author = {Mitzscherling, Julia and MacLean, Joana and Lipus, Daniel and Bartholom{\"a}us, Alexander and Mangelsdorf, Kai and Lipski, Andr{\´e} and Roddatis, Vladimir and Liebner, Susanne and Wagner, Dirk}, title = {Nocardioides alcanivorans sp. nov., a novel hexadecane-degrading species isolated from plastic waste}, series = {International journal of systematic and evolutionary microbiology}, volume = {72}, journal = {International journal of systematic and evolutionary microbiology}, number = {4}, publisher = {Microbiology Society}, address = {London}, issn = {1466-5026}, doi = {10.1099/ijsem.0.005319}, pages = {11}, year = {2022}, abstract = {Strain NGK65(T), a novel hexadecane degrading, non-motile, Gram-positive, rod-to-coccus shaped, aerobic bacterium, was isolated from plastic polluted soil sampled at a landfill. Strain NGK65(T) hydrolysed casein, gelatin, urea and was catalase-positive. It optimally grew at 28 degrees C. in 0-1\% NaCl and at pH 7.5-8.0. Glycerol, D-glucose, arbutin, aesculin, salicin, potassium 5-ketogluconate. sucrose, acetate, pyruvate and hexadecane were used as sole carbon sources. The predominant membrane fatty acids were iso-C-16:0 followed by iso-C(17:)0 and C-18:1 omega 9c. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and hydroxyphosphatidylinositol. The cell-wall peptidoglycan type was A3 gamma, with LL-diaminopimelic acid and glycine as the diagnostic amino acids. MK 8 (H-4) was the predominant menaquinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK65(T) belongs to the genus Nocardioides (phylum Actinobacteria). appearing most closely related to Nocardioides daejeonensis MJ31(T) (98.6\%) and Nocardioides dubius KSL-104(T) (98.3\%). The genomic DNA G+C content of strain NGK65(T) was 68.2\%. Strain NGK65(T) and the type strains of species involved in the analysis had average nucleotide identity values of 78.3-71.9\% as well as digital DNA-DNA hybridization values between 22.5 and 19.7\%, which clearly indicated that the isolate represents a novel species within the genus Nocardioides. Based on phenotypic and molecular characterization, strain NGK65(T) can clearly be differentiated from its phylogenetic neighbours to establish a novel species, for which the name Nocardioides alcanivorans sp. nov. is proposed. The type strain is NGK65(T) (=DSM 113112(T)=NCCB 100846(T)).}, language = {en} } @article{KamjunkeBeckersHerzsprungetal.2022, author = {Kamjunke, Norbert and Beckers, Liza-Marie and Herzsprung, Peter and von T{\"u}mpling, Wolf and Lechtenfeld, Oliver and Tittel, J{\"o}rg and Risse-Buhl, Ute and Rode, Michael and Wachholz, Alexander and Kallies, Rene and Schulze, Tobias and Krauss, Martin and Brack, Werner and Comero, Sara and Gawlik, Bernd Manfred and Skejo, Hello and Tavazzi, Simona and Mariani, Giulio and Borchardt, Dietrich and Weitere, Markus}, title = {Lagrangian profiles of riverine autotrophy, organic matter transformation, and micropollutants at extreme drought}, series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, volume = {828}, journal = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2022.154243}, pages = {14}, year = {2022}, abstract = {On their way from inland to the ocean, flowing water bodies, their constituents and their biotic communities are ex-posed to complex transport and transformation processes. However, detailed process knowledge as revealed by La-grangian measurements adjusted to travel time is rare in large rivers, in particular at hydrological extremes. To fill this gap, we investigated autotrophic processes, heterotrophic carbon utilization, and micropollutant concentrations applying a Lagrangian sampling design in a 600 km section of the River Elbe (Germany) at historically low discharge. Under base flow conditions, we expect the maximum intensity of instream processes and of point source impacts. Phy-toplankton biomass and photosynthesis increased from upstream to downstream sites but maximum chlorophyll con-centration was lower than at mean discharge. Concentrations of dissolved macronutrients decreased to almost complete phosphate depletion and low nitrate values. The longitudinal increase of bacterial abundance and production was less pronounced than in wetter years and bacterial community composition changed downstream. Molecular analyses revealed a longitudinal increase of many DOM components due to microbial production, whereas saturated lipid-like DOM, unsaturated aromatics and polyphenols, and some CHOS surfactants declined. In decomposition exper-iments, DOM components with high O/C ratios and high masses decreased whereas those with low O/C ratios, low masses, and high nitrogen content increased at all sites. Radiocarbon age analyses showed that DOC was relatively old (890-1870 years B.P.), whereas the mineralized fraction was much younger suggesting predominant oxidation of algal lysis products and exudates particularly at downstream sites. Micropollutants determining toxicity for algae (terbuthylazine, terbutryn, isoproturon and lenacil), hexachlorocyclohexanes and DDTs showed higher concentrations from the middle towards the downstream part but calculated toxicity was not negatively correlated to phytoplankton. Overall, autotrophic and heterotrophic process rates and micropollutant concentrations increased from up-to down-stream reaches, but their magnitudes were not distinctly different to conditions at medium discharges.}, language = {en} } @phdthesis{MogrovejoArias2021, author = {Mogrovejo Arias, Diana Carolina}, title = {Assessment of the frequency and relevance of potentially pathogenic phenotypes in microbial isolates from Arctic environments}, school = {Universit{\"a}t Potsdam}, pages = {125}, year = {2021}, abstract = {The Arctic environments constitute rich and dynamic ecosystems, dominated by microorganisms extremely well adapted to survive and function under severe conditions. A range of physiological adaptations allow the microbiota in these habitats to withstand low temperatures, low water and nutrient availability, high levels of UV radiation, etc. In addition, other adaptations of clear competitive nature are directed at not only surviving but thriving in these environments, by disrupting the metabolism of neighboring cells and affecting intermicrobial communication. Since Arctic microbes are bioindicators which amplify climate alterations in the environment, the Arctic region presents the opportunity to study local microbiota and carry out research about interesting, potentially virulent phenotypes that could be dispersed into other habitats around the globe as a consequence of accelerating climate change. In this context, exploration of Arctic habitats as well as descriptions of the microbes inhabiting them are abundant but microbial competitive strategies commonly associated with virulence and pathogens are rarely reported. In this project, environmental samples from the Arctic region were collected and microorganisms (bacteria and fungi) were isolated. The clinical relevance of these microorganisms was assessed by observing the following virulence markers: ability to grow at a range of temperatures, expression of antimicrobial resistance and production of hemolysins. The aim of this project is to determine the frequency and relevance of these characteristics in an effort to understand microbial adaptations in habitats threatened by climate change. The isolates obtained and described here were able to grow at a range of temperatures, in some cases more than 30 °C higher than their original isolation temperature. A considerable number of them consistently expressed compounds capable of lysing sheep and bovine erythrocytes on blood agar at different incubation temperatures. Ethanolic extracts of these bacteria were able to cause rapid and complete lysis of erythrocyte suspensions and might even be hemolytic when assayed on human blood. In silico analyses showed a variety of resistance elements, some of them novel, against natural and synthetic antimicrobial compounds. In vitro experiments against a number of antimicrobial compounds showed resistance phenotypes belonging to wild-type populations and some non-wild type which clearly denote human influence in the acquisition of antimicrobial resistance. The results of this project demonstrate the presence of virulence-associated factors expressed by microorganisms of natural, non-clinical environments. This study contains some of the first reports, to the best of our knowledge, of hemolytic microbes isolated from the Arctic region. In addition, it provides additional information about the presence and expression of intrinsic and acquired antimicrobial resistance in environmental isolates, contributing to the understanding of the evolution of relevant pathogenic species and opportunistic pathogens. Finally, this study highlights some of the potential risks associated with changes in the polar regions (habitat melting and destruction, ecosystem transition and re-colonization) as important indirect consequences of global warming and altered climatic conditions around the planet.}, language = {en} }