Photoproduction of Hydrogen by Alginate Immobilised Cultures of Rhodobacter capsulatus KU002 Isolated from Tannery Effluents

Abstract

The hydrogen producing ability of a purple non-sulphur phototrophic bacterium Rhodobacter capsulatus KU002, isolated from tannery effluents, was studied by immobilising it with alginate. Alginate immobilisation promoted the production of higher amounts of hydrogen when incubated for 120 h in lactate, malate and mannitol containing medium at pH 7.0 ± 0.2. Rb. capsulatus opted L-cystine as the nitrogen source for maximum hydrogen production. L-cystine, at a concentration of 0.35 g/L, caused an enhancement under anaerobic light conditions. The highest average value of hydrogen produced in vials for the whole period of measurements after nitrogen limitation with L-cystine was 147.4 ml/L/day. Hydrogen production rates observed in this study were 6.14 ml/L/h. The results of the investigation are discussed in this paper.