Meinhard Simon

Meinhard's plenary title is: Cycling of vitamin B12 and B7 vitamers by proto- and auxotrophic marine bacteria

Vitamin B12 (cobalamin) is an essential cofactor for most marine prokaryotes and eukaryotes. Synthesized solely by about 30% of prokaryotes its scarce availability impacts microbial interactions and community dynamics. Vitamin B7, biotin, is produced by about 90% of all eukaryotes and assumed to be produced by the majority of prokaryotes. Recent experimental and genomic analyses, however, suggest that B7 auxotrophy of prokaryotes, including marine lineages, is much more prevalent than assumed. In this talk I will shed light on our recent studies on the complex interactions and interplay of pro- and eukaryotic marine microbes to synthesize, salvage and share vitamins B12 and B7 and the respective vitamers. These findings have important implications for our understanding of the significance of these vitamins in marine microbial communities.