Thriving on Methane

摘要

Some hydrate deposits are actual ecosystems. They host not only methanogens—the bacteria that make the methane—and other microbes but also worms and mussels that sometimes live on top of deposits, all feeding directly or indirectly on slowly released gases. The anaerobic methanogens are members of the kingdom Archaea (meaning "ancient"), a collection of bacteria that thrive under extreme conditions. How far down these organisms live is unknown; they could define the bottom of the biosphere. Drillers have found microbes nearly two miles down in solid earth, and probably have not reached the limit.