Nitrogenase, Hydrogenase and Hydrogen Production by Cyanobacteria

2 Summary Hydrogen has the potential to provide a clean, storable, transportable and renewable source of energy that can meet the need for power throughout the world. Biological production of hydrogen, especially by photosynthetic microorganisms that use sunlight for energy, provides a renewable source of hydrogen for fuel cells. Nitrogen-fixing cyanobacteria can produce hydrogen in an aerobic environment by sequestering hydrogenases and nitrogenases in specialized microoxic cells called heterocysts. Several studies with cyanobacteria in bioreactors has demonstrated the feasibility of producing hydrogen in an aerobic environment using these microalgae. Genetic modifications of cyanobacteria to improve the efficiency of hydrogen production using either nitrogenase or hydrogenase should lead to the development of commercially practical hydrogen-producing strains in the foreseeable future.