earticle

영어

Biological hydrogen production, using microorganisms, is an exciting field of technology development that offers potential production of usable hydrogen from a variety of renewable resources. Microbial hydrogen production is mainly based on H2 evolving enzyme, hydrogenase, specifically [Fe] hyrogenase. However, [Fe] hydrogenase has substantial limitation because of its oxygen-sensitive property. Thus in this work, we focused on [NiFe] hydrogenases as another target enzymes for microbial H2 production. Even they have relatively lower activity to [Fe] hydrogenase, they have high oxygen tolerance. This property is important to build more robust process for biohydrogen production. As a model system, recombinant E. coli which expressed [NiFe] hydrogenase was investigated for biohydrogen production. As target enzymes, [NiFe] hydrogenases from E. coli and H. marinus was cloned and expressed in E. coli BL21 because it is a non H2-producing strain. Up to now, it is generally known as [NiFe] hydrogenase is involved in H2-uptake process. However, in this work, E. coli BL21 expressing [NiFe] hydrogenase produced hydrogen actively compared to wild type BL21. Recombinant [NiFe] hydrogenase was also isolated as extract form or purified form and in vitro activity was investigated. Even [NiFe] hydrogenase origated from E. coli has oxygen tolerance, that from H. marinus has more highly tolerant property to oxygen. It showed 2-fold higher activity than E. coli [NiFe] hydrognease under normal atmospheric condition.