A directed genome evolution method to enhance hydrogen production in .

Nitrogenase-dependent H production by photosynthetic bacteria, such as , has been extensively investigated. An important limitation to increase H production using genetic manipulation is the scarcity of high-throughput screening methods to detect possible overproducing mutants. Previously, we engineered strains that emitted fluorescence in response to H and used them to identify mutations in the nitrogenase Fe protein leading to H overproduction.