Nitrile hydratase and its application to industrial production of acrylamide

Nitrile hydratase (NHase) was discovered in our laboratory. This enzyme was purified and characterized from various microorganisms. NHases are roughly classified into two groups according to the metal involved: Fe-type and Co-type. NHases are expected to have great potential as catalysts in organic chemical processing because they can convert nitriles to the corresponding higher-value amides under mild conditions. We have used microbial enzymes for the production of useful compounds: NHase has been used for the industrial production (production capacity: 30,000 tons/year) of acrylamide from acrylonitrile. This is the first successful example of a biotransformation process for the manufacture of a commodity chemical. This review summarizes the history of NHase studied not only from a basic standpoint but also from an applied point of view.