[Dark metabolism of Rhodospeudomonas sulfidophila].

A new strain of phototrophic purple bacterium Rhodopseudomonas sulfidophila RP-6 has been isolated from samples of the salty meromictic lake Repnoye. The bacterium utilizes thiosulphate yielding sulphates and assimilates molecular hydrogen in the darkness under aerobic conditions. Thiosulphate stimulates fixation of 14C-bicarbonate by the cells both in the light and darkness. Organic compounds are necessary for growth of the bacterium in the darkness. R. sulphidophila RP-6, R. palustus, and Rhodomicrobium vanniellii CO-1 do not grow in the presence of carbon monoxide neither in the light or in the darkness.