Metaproteogenomic Profiling of Chemosynthetic Microbial Biofilms Reveals Metabolic Flexibility During Colonization of a Shallow-Water Gas Vent

Tor Caldara is a shallow-water gas vent located in the Mediterranean Sea, with active venting of CO 2 and H S. At Caldara, filamentous microbial biofilms, mainly composed Epsilon- Gammaproteobacteria , grow on substrates exposed to venting. In this study, we took metaproteogenomic approach identify metabolic potential situ expression central pathways at two stages biofilm maturation. Our findings indicate that inorganic reduced sulfur species are main electron donors carbon source for which conserve energy by oxygen nitrate respiration, fix dinitrogen detoxify heavy metals. Three metagenome-assembled genomes (MAGs), representative key members community, were also recovered. Metaproteomic data show metabolically chemoautotrophic sulfide-oxidizing Epsilonproteobacteria dominated young while become prevalent established community. The co-expression different sulfide oxidation these classes bacteria suggests exposure concentrations within as well fine-tuned adaptations enzymatic complexes. Taken together, our demonstrate shift taxonomic composition associated activity biofilms course colonization process.