Microalgae: a green source of renewable H2

This article summarizes recent advances in the field of algal hydrogen production. Two fundamental approaches are being developed. One involves the temporal separation of the usually incompatible reactions of O2 and H2 production in green algae, and the second involves the use of classical genetics to increase the O2 tolerance of the reversible hydrogenase enzyme. The economic and environmental impact of a renewable source of H2 are also discussed.