Project Description
Rationale
The relevance of marine bacteria in global nutrient cycles is well established. However, the ecophysiological niches of most of the respective bacteria, their metabolic interdependencies, and crucial protein functions are only poorly understood, or not understood at all. The DFG research unit FOR 2406 (Proteogenomics Of Marine Polysaccharide Utilization (POMPU)) is working on mechanisms of bacterial polysaccharide utilization during marine phytoplankton blooms.
Abundances of major bacterial populations during a bacterioplankton bloom as assessed by Catalyzed Reporter Deposition Fluorescence in situ Hybridization (CARD-FISH) (Teeling, Fuchs et al., Science 2012).
(A) Chlorophyll a (Chl a) concentration, DAPI–based total cell counts (TCC), and bacterial counts (probe EUB338 I-III) during the year 2009; diatom-dominated spring blooms (1) and dinoflagellate-dominated summer blooms (2) are marked with green boxes; triangles on top mark accessory samples: metagenomics (red), metaproteomics (blue), and 16S rRNA gene tag sequencing (magenta).
(B) Relative abundances of selected Flavobacteriia: Ulvibacter spp. (ULV-995), Formosa spp. (FORM-181A), and Polaribacter spp. (POL740)
The FOR 2406 consortium focuses on proteomic and genomic functional analyses of marine bacteria of the phylum Bacteroidetes that are specialized on polysaccharide degradation. The synergistic expertise of the consortium partners in bacterial diversity, ecology, biochemistry, enzymology, (meta)genomics and (meta)proteomics are being applied to obtain a detailed, culture-independent view into the physiologies and functions of distinct bacterial populations. Physiological proteogenomics of cultivable environmentally relevant key bacteria under defined in vitro conditions complement the in situ studies. In-depth biochemical characterizations of identified key proteins are being used to determine strategies of marine polysaccharide utilization and to unravel the specific ecophysiological roles of distinct bacterial populations during algal blooms.
Schematic presentation of the integration of the different project partners and the structure of the POMPU consortium. Area A focuses on the proteogenomic analysis of polysaccharide-degrading marine Bacteroidetes and the biochemical characterization of PUL-specific proteins; Area B investigates the in situ significance of strains, their transporters and enzymes. *The Emmy Noether project was granted in 2015.