Screening of culture collection afforded nitrile-utilizing fungi belonging to genera Aspergillus, Talaromyces and Penicillium. Fusarium solani OI was enriched from soil using 3-cyanopyridine as the sole source of nitrogen. This strain, and Penicillium multicolor CCF 2244 (the best one of the culture collection strains), showed comparable specific benzonitrile-hydrolyzing activities (0.95 and 0.87 mu mol of benzoic acid h(-1) mg(-1) of dry cell weight at 28 degrees C, respectively). These fungi showed similar substrate specificities for substituted benzonitriles and heterocyclic nitriles but different pH and temperature optima (pH 8 and 38 degrees C for P multicolor, pH 7 and 48 degrees C for F solani). Amides as by-products were produced from some heterocyclic nitriles. Both fungi showed an amidase activity for nicotinamide. (c) 2005 Elsevier Inc. All rights reserved.