Bioconversion of acrylonitruke to acrylamide using a thermostable nitrile hydratase

Although providing an attractive route for production of crrylamide from acrylonitrile, utilization of nitrile hydratase en zymes has been limited by the requirement for low temperatu rebioconversion conditions. Thisrreportsummarizes a search for thermostable nitrile hydratases from aerobic moderate thermophiles screened for ability to grow on acrylonitrileatt concentrations to 1% at elevated temperatures. A new isolate Bacillus sp. BR449 constitutively expresses a thermostble nitrile hydratase with properties iccluding low substrate inhibition and broad temperature range with optimal activity at 55°C. With prolonged exposure, BR449 nitrile hydratase exhibited temperature-dependent inactivation by acrylonitrile, which is attributed to alkylation of nucleophilic sites on the enzymes/