Nocardia globerula NHB-2: a versatile nitrile-degrading organism

Abstract

A versatile nitrile-degrading bacterium was isolated by enrichment culture from the soil of a forest near Manali, Himachal Pradesh, India, and was identified as Nocardia globerula. This organism contains 3 enzymes with nitrile-degrading activity: nitrilase, nitrile hydratase, and amidase. Nocardia globerula NHB-2 cells grown on nutrient broth supplemented with 1% glucose and 0.1% yeast extract exhibited nitrile hydratase–amidase activity specific for saturated aliphatic nitriles or amide, while addition of acetonitrile in nutrient broth yielded cells with nitrile hydratase–amidase that in addition to saturated aliphatic nitriles–amide also hydrolyzed aromatic amide. Nocardia globerula NHB-2 cultivated on nutrient broth containing propionitrile exhibited nitrilase activity that hydrolyzed aromatic nitrile and unsaturated aliphatic nitrile. The versatility of this organism in the hydrolysis of various nitriles and amides makes it a potential bioresource for use in organic synthesis.Key words: Nocardia globerula NHB-2, nitrilase, nitrile hydratase, amidase, nitrile–amide degradation.