Photoproduction of hydrogen from sewage by immobilized cells of Chromatium species IA.

Immobilized cells of two Chromatium species produced hydrogen continuously for more than 160 hr in 60% and 80% sewage. One strain showing high optimum range of sulfide tolerance (up to 9 mM) produced more hydrogen in 80% sewage while the less sulfide tolerating strain (up to 6 mM) showed hydrogen photoproduction in 60% sewage. Cells were immobilized in alginate and stable hydrogen photoproduction was observed for more than one week. Appropriate strategy necessary for the treatment of sewage and similar industrial effluents for energy reclamation is discussed.