Microbial dynamics in shallow CO2 seeps system off Panarea Island (Italy)

Abstract Shallow-water hydrothermal vents are extreme environments characterized by high temperatures, low pH, and CO 2 concentrations; therefore, they considered as suitable laboratories for studying the effect of global changes on marine microbes. We hypothesized a direct prokaryotic community structure functioning in Panarea Island’s system. Sampling was conducted along 9-station transect three active emission points. The water column stratified with thermocline at 25 m depth deep chlorophyll maximum between 50 100 m. Prokaryotic abundance ranged from 0.2 to 1.5 × 10 9 cells L −1 , carbon production 2.4 75.4 ng C h exoenzymatic activities degrading proteins, phosphorylated compounds, polysaccharides were order 4–28, 2–31 0.2–4.16 nM respectively. While microbial shaped column's physical structure, alkaline phosphatase beta-glucosidase seemed be enhanced fluids. 16S rRNA gene amplicon sequencing analysis identified surface, deep, vent-influenced community. In terms relative members SAR11 group dominated column, alongside Synechococcus Prochlorococcus surface bottom samples, Vent-influenced stations presence Thiomicrorhabdus sulfur-oxidizer chemolithoautotroph. Overall, this study provides insights coupling biogeochemical cycling nutrients low-pH conditions (CO H S-based), thus addressing some opened questions about response microbes acidification.