Cells grown in BG110 supplemented with KCN, rotenone, DCMU, and DL-glyceraldehyde under light
condition for 24 h showed enhanced H2 production. Cells grown in BG11 medium showed only marginal
H2 production and its production was hardly increased by the inhibitors tested. H2 production with either
20 mM KCN or 50 lM DCMU in BG110 medium was 22 lmol H2 mg chl a1 h1, threefold higher than the
control.