Biotransformation of nitriles to amides using soluble and immobilized nitrile hydratase from Rhodococcus erythropolis A4

Abstract

A semi-purified nitrile hydratase from Rhodococcus erythropolis A4 was applied to biotransformations of 3-oxonitriles 1a– 4a, 3-hydroxy-2-methylenenitriles 5a– 7a, 4-hydroxy-2-methylenenitriles 8a– 9a, 3-hydroxynitriles 10a– 12a and 3-acyloxynitrile 13a into amides 1b– 13b. Cross-linked enzyme aggregates (CLEAs) with nitrile hydratase and amidase activities (88% and 77% of the initial activities, respectively) were prepared from cell-free extract of this microorganism and used for nitrile hydration in presence of ammonium sulfate, which selectively inhibited amidase activity. The genes nha1 and nha2 coding for α and β subunits of nitrile hydratase were cloned and sequenced.