M. Amann results 36
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The Toxicology Investigators Consortium 2024 Annual ReportNARA Subscribed
Assessing the effectiveness of toe buttressing on slope stability through monitoring and numerical modelling in a quarry in GermanyNARA Subscribed
Slope instability poses significant challenges in geotechnical engineering, necessitating effective mitigation strategies. Among these strategies, toe buttressing has emerged as a prominent method, involving the strategic placement of materials at the base of unstable slopes. However, the efficacy of toe buttressing remains insufficiently explored in scientific literature, particularly through the integration of real-time moni...
Calcification and chronic inflammation of the vascular wall is a high-risk factor for cardiovascular mortality, especially in patients with chronic uremia. For the reduction or prevention of rapid disease progression, no specific treatment options are currently available. This study aimed to evaluate an adenine-based uremic mouse model for studying medial vessel calcification and senescence-associated secretory phenotype (SASP...
Strong seasonal differences of bacterial polysaccharide utilization in the North Sea over an annual cycleNARA Subscribed
Summary Marine heterotrophic bacteria contribute considerably to global carbon cycling, in part by utilizing phytoplankton‐derived polysaccharides. The patterns and rates of two different polysaccharide utilization modes – extracellular hydrolysis and selfish uptake – have previously been found to change during spring phytoplankton bloom events. Here we investigated seasonal changes in bacterial utilization of three polysaccha...
Lack of association between proton pump inhibitor use and brain aging: a cross-sectional studyNARA Subscribed
Purpose Due to conflicting scientific evidence for an increased risk of dementia by intake of proton pump inhibitors (PPIs), this study investigates associations between PPI use and brain volumes, estimated brain age, and cognitive function in the general population. Methods Two surveys of the population-based Study of Health in Pomerania (SHIP) conducted in Northeast Germany were used. In total, 2653 participants underwent br...
Experimental Investigation of Gas Dynamic Effects Using Nanoporous Synthetic Materials as Tight Rock AnaloguesNARA Subscribed
To improve the understanding of gas transport processes in tight rocks (e.g., shales), systematic flow tests with different gases were conducted on artificial micro- to nanoporous analogue materials. Due to the rigidity of these systems, fluid-dynamic effects could be studied at elevated pressures without interference of poro-elastic effects. Flow tests with narrow capillaries did not reveal any viscosity anomaly in a confined...
Short‐term changes in polysaccharide utilization mechanisms of marine bacterioplankton during a spring phytoplankton bloomNARA Subscribed
Summary Spring phytoplankton blooms in temperate environments contribute disproportionately to global marine productivity. Bloom‐derived organic matter, much of it occurring as polysaccharides, fuels biogeochemical cycles driven by interacting autotrophic and heterotrophic communities. We tracked changes in the mode of polysaccharide utilization by heterotrophic bacteria during the course of a diatom‐dominated bloom in the Ger...
Summary The first interaction of water column‐derived organic matter with benthic microbial communities takes place in surface sediments which are acting as biological filters catalyzing central steps of elemental cycling. Here we analyzed the bacterial diversity and community structure of sediment top layers at seven sites in the North Sea where sediment properties ranged from coarse‐grained and highly permeable to fine‐grain...
Genomic and physiological analyses of ‘ Reinekea forsetii ’ reveal a versatile opportunistic lifestyle during spring algae bloomsNARA Subscribed
Summary Gammaproteobacterial Reinekea spp. were detected during North Sea spring algae blooms in the years 2009‐2012, with relative abundances of up to 16% in the bacterioplankton. Here, we explore the ecophysiology of ‘R. forsetii' strain Hel1_31_D35 that was isolated during the 2010 spring bloom using (i) its manually annotated, high‐quality closed genome, (ii) re‐analysis of in situ data from the 2009–2012 blooms and (iii)...
Direct‐geneFISH: a simplified protocol for the simultaneous detection and quantification of genes and rRNA in microorganismsNARA Subscribed
Summary Although fluorescence in situ hybridization (FISH) with specific ribosomal RNA (rRNA)‐targeted oligonucleotides is a standard method to detect and identify microorganisms, the specific detection of genes in bacteria and archaea, for example by using geneFISH, requires complicated and lengthy (> 30 h) procedures. Here we report a much improved protocol, direct‐geneFISH, which allows specific gene and rRNA detection with...
Polysaccharide utilisation loci of Bacteroidetes from two contrasting open ocean sites in the North AtlanticNARA Subscribed
Summary Marine Bacteroidetes have pronounced capabilities of degrading high molecular weight organic matter such as proteins and polysaccharides. Previously we reported on 76 Bacteroidetes ‐affiliated fosmids from the North Atlantic Ocean's boreal polar and oligotrophic subtropical provinces. Here, we report on the analysis of further 174 fosmids from the same libraries. The combined, re‐assembled dataset (226 contigs; 8.8 Mbp...
Chlamydial seasonal dynamics and isolation of ‘ C andidatus N eptunochlamydia vexilliferae’ from a T yrrhenian coastal lakeNARA Subscribed
Summary The C hlamydiae are a phylum of obligate intracellular bacteria comprising important human and animal pathogens, yet their occurrence in the environment, their phylogenetic diversity and their host range has been largely underestimated. We investigated the seasonality of environmental chlamydiae in a Tyrrhenian coastal lake. By catalysed reporter deposition fluorescence in situ hybridization, we quantified the small pl...
Comparison of bacterial communities on limnic versus coastal marine particles reveals profound differences in colonizationNARA Subscribed
Summary Marine and limnic particles are hotspots of organic matter mineralization significantly affecting biogeochemical element cycling. Fluorescence in‐situ hybridization and pyrosequencing of 16S rRNA genes were combined to investigate bacterial diversity and community composition on limnic and coastal marine particles > 5 and > 10 μm respectively. Limnic particles were more abundant (average: 1 × 10 7 l −1 ), smaller in si...
Dilution cultivation of marine heterotrophic bacteria abundant after a spring phytoplankton bloom in the N orth S eaNARA Subscribed
Summary The roles of individual bacterioplankton species in the re‐mineralization of algal biomass are poorly understood. Evidence from molecular data had indicated that a spring diatom bloom in the G erman B ight of the N orth S ea in 2009 was followed by a rapid succession of uncultivated bacterioplankton species, including members of the genera U lvibacter , F ormosa , P olaribacter (class F lavobacteria ) and R einekea (cl...
Distribution of a consortium between unicellular algae and the N 2 fixing cyanobacterium UCYN ‐ A in the North Atlantic OceanNARA Subscribed
Summary The globally abundant, uncultured unicellular cyanobacterium UCYN ‐ A was recently discovered living in association with a eukaryotic cell closely related to a prymnesiophyte. Here, we established a double CAtalysed Reporter Deposition‐Fluorescence In Situ Hybridization ( CARD ‐ FISH ) approach to identify both partners and provided quantitative information on their distribution and abundance across distinct water mass...
Summary Anaerobic ammonium‐oxidizing (anammox) bacteria are responsible for a significant portion of the loss of fixed nitrogen from the oceans, making them important players in the global nitrogen cycle. To date, marine anammox bacteria found in marine water columns and sediments worldwide belong almost exclusively to the ‘ Candidatus Scalindua’ species, but the molecular basis of their metabolism and competitive fitness is p...
Genomic content of uncultured Bacteroidetes from contrasting oceanic provinces in the North Atlantic OceanNARA Subscribed
Summary Bacteroidetes are widespread in marine systems where they play a crucial role in organic matter degradation. Whole genome analysis of several strains has revealed a broad glycolytic and proteolytic potential. In this study, we used a targeted metagenomic approach to investigate the degradation capabilities of distinct Bacteroidetes clades from two contrasting regions of the North Atlantic Ocean, the Polar Biome (BPLR)...
GeneFISH – an in situ technique for linking gene presence and cell identity in environmental microorganismsNARA Subscribed
Summary Our knowledge concerning the metabolic potentials of as yet to be cultured microorganisms has increased tremendously with the advance of sequencing technologies and the consequent discoveries of novel genes. On the other hand, it is often difficult to reliably assign a particular gene to a phylogenetic clade, because these sequences are usually found on genomic fragments that carry no direct marker of cell identity, su...
Summary ‘ Candidatus Magnetobacterium bavaricum’ is unusual among magnetotactic bacteria (MTB) in terms of cell size (8–10 µm long, 1.5–2 µm in diameter), cell architecture, magnetotactic behaviour and its distinct phylogenetic position in the deep‐branching Nitrospira phylum. In the present study, improved magnetic enrichment techniques permitted high‐resolution scanning electron microscopy and energy dispersive X‐ray analysi...
Latitudinal distribution of prokaryotic picoplankton populations in the Atlantic OceanNARA Subscribed
Summary Members of the prokaryotic picoplankton are the main drivers of the biogeochemical cycles over large areas of the world's oceans. In order to ascertain changes in picoplankton composition in the euphotic and twilight zones at an ocean basin scale we determined the distribution of 11 marine bacterial and archaeal phyla in three different water layers along a transect across the Atlantic Ocean from South Africa (32.9°S)...
A microdiversity study of anammox bacteria reveals a novel Candidatus Scalindua phylotype in marine oxygen minimum zonesNARA Subscribed
Summary The anaerobic oxidation of ammonium (anammox) contributes significantly to the global loss of fixed nitrogen and is carried out by a deep branching monophyletic group of bacteria within the phylum Planctomycetes . Various studies have implicated anammox to be the most important process responsible for the nitrogen loss in the marine oxygen minimum zones (OMZs) with a low diversity of marine anammox bacteria. This compr...