[Development of a pure Methanosarcina biotype 2 culture on acetate].

A pure culture of the obligate anaerobe methanosarcina, biotype 2, was isolated using an original technique of dilution in agar and inoculation into a preliminarily reduced medium. Additional organic substances, in particular yeast extract, are necessary for germination of a small number of packets in the course of isolation. The methanosarcina can use, during several inoculations, acetate as a sole source of carbon and energy, and does not require hydrogen as the main substrate of catabolism. The organic substances being tested (with an exception of pyruvate, hemin and cysteine which somewhat increased the lag phase) had no significant effect on growth and production of methane. Apparently, the mechanosarcina, biotype 2, should be referred to as an individual species.