In the present study, photoproduction of hydrogen by Allochromatium sp. strain GSKRLMBKU-01 isolated from marine water was measured under different cultural conditions. Hydrogen production was measured by using a Gas chromatography using argon gas as a carrier. Among different carbon and nitrogen sources used, succinate induced maximum hydrogen (5.68 +/- 0.27 mL) production by immobilized cells, while free cells recorded 4.24 +/- 0.30 mL of hydrogen under anaerobic light conditions. Immobilization of cells resulted in increased production of hydrogen. Ammonium chloride promoted more amounts of hydrogen production (2.68 +/- 0.29 mL) by free cells, whereas glycine enhanced the hydrogen production upto 4.82 +/- 0.36 mL in immobilized cells. In formic acid and urea, less hydrogen production was observed in both free and immobilized cells compared to other sources. Cumulative hydrogen production by the bacterium was recorded with the progress in incubation period. Incubation period of 192 h, pH of 7.0 and temperature at 30 degrees C were found to be optimum for the maximum hydrogen production. Significance of the above results was discussed in light of existing literature. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.