Geochemical and Microbial Characterization of Volcanic–Hydrothermal Systems on Vulcano Island
The volcanic–hydrothermal systems of La Fossa crater and Levante Bay on Vulcano Island (Italy) represent a natural laboratory for investigating interactions between geochemistry and microbial ecology in extreme environments. This study integrates geochemical analyses of soils, interstitial gases, waters, and CO2-acidified soil leachates with 16S rRNA gene sequencing to identify the environmental drivers shaping microbial communities across terrestrial and marine-influenced hydrothermal settings. Geochemical data revealed mixed magmatic, hydrothermal, and atmospheric gas contributions, intense fluid–rock interaction, acid weathering, trace metal mobilization, and sulfur mineral precipitation. Microbial community composition was primarily structured by deterministic environmental filtering, with pH and sulfur speciation emerging as major controlling factors. Sulfur-rich terrestrial sites were dominated by Thiomicrospiraceae, whereas Sulfurovaceae prevailed in marine-influenced environments. Extreme geochemical conditions constrained phylogenetic diversity while promoting functional specialization and metabolic flexibility linked to sulfur, carbon, and nitrogen cycling. These results provide insights into microbial adaptation in volcanic systems relevant to early Earth and astrobiological analog environments.
The volcanic–hydrothermal systems of La Fossa crater and Levante Bay on Vulcano Island (Italy) represent a natural laboratory for investigating interactions between geochemistry and microbial ecology in extreme environments. This study integrates geochemical analyses of soils, interstitial gases, waters, and CO2-acidified soil leachates with 16S rRNA gene sequencing to identify the environmental drivers shaping microbial communities across terrestrial and marine-influenced hydrothermal settings. Geochemical data revealed mixed magmatic, hydrothermal, and atmospheric gas contributions, intense fluid–rock interaction, acid weathering, trace metal mobilization, and sulfur mineral precipitation. Microbial community composition was primarily structured by deterministic environmental filtering, with pH and sulfur speciation emerging as major controlling factors. Sulfur-rich terrestrial sites were dominated by Thiomicrospiraceae, whereas Sulfurovaceae prevailed in marine-influenced environments. Extreme geochemical conditions constrained phylogenetic diversity while promoting functional specialization and metabolic flexibility linked to sulfur, carbon, and nitrogen cycling. These results provide insights into microbial adaptation in volcanic systems relevant to early Earth and astrobiological analog environments.
Water Research Institute