Production of biohydrogen by recombinant expression of [NiFe]-hydrogenase 1 in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Background  

Hydrogenases catalyze reversible reaction between hydrogen (H₂) and proton. Inactivation of hydrogenase by exposure to oxygen is a critical limitation in biohydrogen production since strict anaerobic conditions are required. While FeFe]-hydrogenases are irreversibly inactivated by oxygen, it was known that NiFe]-hydrogenases are generally more tolerant to oxygen. The physiological function of NiFe]-hydrogenase 1 is still ambiguous. We herein investigated the H₂ production potential of NiFe]-hydrogenase 1 of Escherichia coli in vivo and in vitro. The hya A and hya B genes corresponding to the small and large subunits of NiFe]-hydrogenase 1 core enzyme, respectively, were expressed in BL21, an E. coli strain without H₂ producing ability.