Analogously to the ocean-bottom black/white smokers, “continental smokers” have recentlybeen defined as sites of mantle degassing through continental crust. The goal of this research,carried out within the Deep Carbon Observatory Community, is to investigate the role of deeplysourcedfluids in niche ecosystem differentiation in European continental smokers. A 16SrRNA gene survey of microbial communities was carried out on 11 geothermal manifestationsof northern Greece, all showing a distinct contribution of mantle fluids (R/Ra up to 1.2)that allow to classify them as continental smokers. The selected sites cover a wide range oftemperatures (15-77 °C), pH (6.11-8.46), Eh (-289 – 40 mV), salinities (TDS 0.4-38 g/L) andshow significant differences in energy sources for microbial life, like H2 (up to 0.8 μmol/L),CH4 (up to 400 μmol/L), NH4 (up to 112 μmol/L), sulphide (up to 103 μmol/L), Fe (up to130 mmol/L). Illumina sequencing revealed negligible presence of Archaea and dominance ofActinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. Different bacterial taxa dominatedepending on physico-chemical features: Deinococcus-Thermus dominates the hottest siteswhile chemoautotrophic genera (Sulfurovum and Sulfurimonas) are abundant in the mostreducing H2S-rich waters. Signatures of deep-sea vent microbial ecosystems were detected inmost assemblages, together with novel taxa.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2017|