OXIDATION OF MOLECULAR-HYDROGEN AND CARBON-MONOXIDE BY FACULTATIVELY CHEMOLITHOTROPHIC VANADATE-REDUCING BACTERIA

New data on physiology of two recently isolated species of facultative ly anaerobic. and facultatively chemolithotrophic vanadate-reducing ba cteria, Pseudomonas vanadiumreductants and Pseudomonas isachenkovii, a re presented. In addition to heterotrophic growth, both cultures can g row autotrophically under aerobic and anaerobic conditions. Under thes e conditions molecular hydrogen or carbon monoxide may be used as elec tron donors. Pentavalent vanadium serves as a terminal electron accept or under anaerobic conditions and is reduced to tetravalent vanadium.