Clearly, more work is needed to accurately define the metabolic pathways and functional regulations involved in the H2 photoproduction process under phosphorus-deprived conditions in marine green microalgae Chlorella sp., however, the response of Chlorella sp. to phosphorus deprivation demonstrates significant similarities with fresh water C. reinhardtii: cultures passed through the same physiological stages, including oxygen production with accumulation of starch,
oxygen consumption, evidently due to inactivation of PSII, establishment of anaerobiosis in cultures,
H2 photoproduction and termination.