Novel Barite Chimneys at the Loki's Castle Vent Field Shed Light on Key Factors Shaping Microbial Communities and Functions in Hydrothermal Systems

摘要: In order to fully understand the cycling of elements in hydrothermal systems it is critical intra-field variations geochemical and microbiological processes both focused, high-temperature diffuse, low-temperature areas. To reveal important causes effects this variation, we performed an extensive chemical characterization a venting area Loki’s Castle Vent Field (LCVF). This area, located at flank large sulfide mound, characterized by numerous chimney-like barite (BaSO4) structures (≤ 1m high) covered with white cotton-like microbial mats. Results from analyses, microscopy (FISH, SEM), 16S rRNA gene amplicon-sequencing metatranscriptomics were compared results previous analyses biofilms growing on black smoker chimneys LCVF. Based our results, constructed conceptual model involving geochemistry microbiology The suggests that CH4 H2S are electron donors for microorganisms areas, whereas utilization H2 seems restricted further implies sub-seafloor can affect energy-landscapes, elemental cycling, metabolic activity primary producers seafloor. mats top active chimneys, unique network single cells Epsilonproteobacteria interconnected threads extracellular polymeric substances (EPS) was seen, differing significantly long filamentous Sulfurovum filaments observed smokers. also induced nucleation crystals suggested play essential role formation chimneys. Furthermore, illustrates how different genera colonize position vent fluid mixing zones within field. may be related niche-specific physical characteristics. Altogether, provides reference future studies importance systematic comparative spatially closely connected niches geobiology systems.