S. Girisham

Influence of different cultural conditions on photoproduction of hydrogen by Rhodopseudomonas palustris KU003.

Photoproduction of hydrogen by Rhodopseudomonas palustris KU003 under different cultural conditions with various carbon and nitrogen sources was investigated. Hydrogen production was measured using a Gas chromatograph. Malate promoted more amounts of hydrogen production under anaerobic light conditions than anaerobic dark conditions. Cumulative hydrogen production by the organism was recorded at various time intervals. Incubation period of 120 hrs was optimum for production of hydrogen. pH 7.0±0.4 was optimum for production of hydrogen. L-glutamic acid was a good nitrogen source for production of hydrogen. Growing cells produced more amount of hydrogen than resting cells. Significance of the above results in presence of existing literature is discussed.

Factors influencing the production of hydrogen by the purple non-sulphur phototrophic bacterium Rhodopseudomonas acidophila KU001

Rhodopseudomonas acidophila KU001 was isolated from leather industry effluents and the effect of different cultural conditions on hydrogen production was studied. Anaerobic light induced more hydrogen production than anaerobic dark conditions. Growing cells produced more amounts of hydrogen between 96 and 144 h of incubation. Resting and growing cells preferred a pH of 6.0 ± 0.24 for hydrogen production. Succinate was the most preferred carbon source for the production of hydrogen while citrate was a poor source of carbon. Acetate and malate were also good carbon sources for hydrogen production under anaerobic light. Among the nitrogen sources, R. acidophila preferred ammonium chloride followed by urea for production of hydrogen. L‐tyrosine was the least preferred nitrogen source by both growing and resting cells.