Biological hydrogen generation can be classified into four categories: (i) direct biophotolysis using green microalgae [2e4] and some cyanobacteria [5], (ii) indirect biophotolysis with other cyanobacteria species and certain nitrogen-fixing bacteria [6,7], (iii) photofermentation of waste and effluents [8] and (iv) dark fermentation of rich sugar wastes [9,10].