The intracellular nitrilase of Nocardia globerula NHB-2 induced by propionitrile catalyses the hydrolysis of 3-cyanopyridine to nicotinic acid without detectable formation of nicotinamide. N. globerula NHB-2 showed highest conversion rate at 40 mM 3 -cyanopyridine, in 0.1 M NaH2PO4/ Na2HPO4 buffer (pH 7.5) containing 5 mM 2-mercaptoethanol. In 11 fed-batch reaction, containing 0.1 M NaH2PO4/NaHPO4 buffer (pH 7.5), 4.2 g resting cells (dry weight), at 35 degrees C, 400 rpm, a total of I mol of 3-cyanopyridine added at feed rate of 0.12 mol h(-1) was converted to nicotinic acid (98.6%) in 9 h. The rate of nicotinic acid production was 26 mmol h(-1) g(-1) DW. (c) 2006 Elsevier Ltd. All rights reserved.