Hydrogen enzymes (hydrogenase) are enzymes that catalyse the reversible oxidation of molecular hydrogen. Hydrogenases classification are based on metal atoms composing the active sites. Most of the enzymes found in nature are active in taking up hydrogen. We have the know how to manipulate the influential parameters to stimulate the activities of the enzymes in microorganisms to be more active in the production of molecular hydrogen.
Bio-hydrogen produced by the enzymes can be used as a conventional fuel. The hydrogen production process can be coupled with biogas fermenters to improve methane production. The hydrogen reacts with carbon dioxide to improve the yield and quality of biogas.