Influence of nitrogen source on hydrogen generation by a photosynthetic bacterium.

Axenic culture of photosynthetic purple sulphur bacterium, isolated from a paper mill effluent, grew best with ammonium chloride as nitrogen source. Cells grown with N2 or ammonium chloride produced hydrogen with initial lag periods of 24 and 48 h, respectively. The maximum amount of hydrogen was evolved by cells grown with N2 and with malate as electron donor.