Hydrogenase

Abstract

An organism was isolated by single-cell technique, which lives anaerobically on an inorganic medium with formate as sole source of C. Formic acid is decomposed as follows: 4 HCOOH = CH4 + 3 CO2 + 2 H2O + 39 kgm. cals. The reaction oc-curred in 2 stages[long dash](1) HCOOH = H2 + CO2, (2) 4 H2 + CO2 = CH4 + 2 H2O[long dash]and is therefore the work of 2 enzymes, formic hydrogenlyase and hydrogenase, with an additional mechanism for activation of CO2 as H acceptor. The organism, tested in washed suspensions, reduced the following 1-C compounds to methane by means of molecular H (i.e., hydrogenase reactions) : CO2, formic acid, CO, formaldehyde (as hexamethylene-tetramine) and methyl alcohol. No compounds tested, containing more than 1 C atom, were reduced by this organism, with production of methane.