Specific enrichment of hyperthermophilic electroactive Archaea from deep hydrothermal vent on electrically conductive support.. EXOELECTRO

While more and more investigations are done to isolate hyperthermophilic exoelectrogen communities from environments, none have been performed yet on Deep Hydrothermal Vent. Sample of Black Smoker chimney from Rainbow site on the Atlantic mid-oceanic ridge have been harvested for enriching exoelectrogens in microbial electrolysis cells under hyperthermophilic (80°C) condition. Two enrichments, one from direct inoculation of crushed chimney and the other one by inoculation of a pre-cultivation on iron(III) oxide, have been performed. In both experiments, a current production was observed from 2.4 A/m² to 5.8 A/m² with a set anode potential of +0.05 vs SHE. Taxonomic affiliation of the exoelectrogen communities obtained exhibited a specific enrichment of Archaea from Thermococcales and Archeoglobales order on the electrode, even when both inoculums were dominated by Bacteria.