Cobalt activation of Bacillus BR449 thermostable nitrile hydratase expressed in Escherichia coli

Expression of nitrile hydratase enzymes utilized in a new "green" process f or acrylamide production has proven difficult in Escherichia coli owing to lack of a cobalt transport system to introduce the required cobalt ion into this host. We describe the expression of a thermostable nitrile hydratase from a moderate thermophile Bacillus sp. BR449 in E. coli in which the coba lt required for enzyme activation is introduced by incubation of the apoenz yme in the presence of Co++ ion at 50 degreesC, yielding active and thermos table enzyme.