RHOBACTER MARINUS SP NOV - A NEW MARINE HYDROGEN PRODUCING PHOTOSYNTHETIC BACTERIUM WHICH IS SENSITIVE TO OXYGEN AND SULFIDE

A new non sulphur photosynthetic bacterium. strain NKPB 0021, was isolated from sea water samples and assigned to the genus Rhodobacter on the basis of morphology and presence of vesicular photosynthetic membranes. Cells are motile rods, 0.6-1.2 mu m in diameter and multiply by binary fission. This isolate is unusual since it is oxygen sensitive and cannot grow aerobically. Strain NKPB 0021 grows best anaerobically in the light and requires NaCl for growth (optimum 1.5%). Cells are capable of assimilatory sulphate reduction, and are sensitive to sulphide, with no growth above 0.7 mM sulphide. The mean DNA base composition is 66.7 mol% G + C. On the basis of this study, we propose strain NKPB 0021 to be the type strain of a new species, Rhodobacter marinus.