초록
Under sulfur-deprived conditions, the metabolism of Chlamydomonas reinhardtii switches to the photoproduction of hydrogen. This process is sustained by both photosystem II-driven water splitting and by the fermentation of stored carbohydrates. We investigated the possibility of using diluted pretreated olive mill wastewaters (OMW), which contain organic acids and sugars, as a substrate on which to grow Chlamydomonas, in order to obtain suitable biomass to produce hydrogen. The cells grown on a mixture of pretreated OMW and TAP (tris-acetate-phosphate) (50% dilution) were found to be richer in carbohydrates and exhibited a greater production of hydrogen (150ml H<SUB>2</SUB>l<SUP>-1</SUP> culture), compared to the control cells (100ml H<SUB>2</SUB>l<SUP>-1</SUP> culture). In these cultures, the hydrogen production process was characterized by a shorter aerobic phase and a longer hydrogen-production period. The results offer a useful perspective for the utilization of olive mill wastewaters, which constitute an environmental problem, particularly in Mediterranean areas, and for increasing the output for hydrogen production with Chlamydomonas.