Enceladus as a Potential Niche for Methanogens and Estimation of Its Biomass.

Enceladus is a potential target for future astrobiological missions. NASA's Cassini spacecraft demonstrated that the Saturnian moon harbors a salty ocean beneath its icy crust and the existence and analysis of the plume suggest water-rock reactions, consistent with the possible presence of hydrothermal vents. Particularly, the plume analysis revealed the presence of molecular hydrogen, which may be used as an energy source by microorganisms ( e.