Promoting R & D in photobiological hydrogen production utilizing mariculture-raised cyanobacteria

This review article explores the potential of using mariculture-raised cyanobacteria as solar energy converters of hydrogen (H-2). The exploitation of the sea surface for large-scale renewable energy production and the reasons for selecting the economical, nitrogenase-based systems of cyanobacteria for H-2 production, are described in terms of societal benefits. Reports of cyanobacterial photobiological H-2 production are summarized with respect to specific activity, efficiency of solar energy conversion, and maximum H-2 concentration attainable. The need for further improvements in biological parameters such as low-light saturation properties, sustainability of H-2 production, and so forth, and the means to overcome these difficulties through the identification of promising wild-type strains followed by optimization of the selected strains using genetic engineering are also discussed. Finally, a possible mechanism for the development of economical large-scale mariculture operations in conjunction with international cooperation and social acceptance is outlined.