The utilization of aromatic, cyclic and heterocyclic nitriles by yeasts

The ability of endomycetalial yeast strains representing Candida fabianii, Candida famata, Candida guilliermondii and Williopsis saturnus to utilize a series of aromatic, cyclic and heterocyclic nitriles as nitrogen source was examined. Varying degrees of utilization of these compounds were noted. Sterically hindered nitrile groups were apparently nor utilized. C. fabianii demonstrated the highest rate of 3-cyanopyridine conversion by the four yeasts and within 24 h, 100% molar conversion was achieved. The cultivation of C. fabianii with aromatic and heterocyclic nitriles and ammonium sulphate as nitrogen source resulted in a low apparently constitutive nitrile- and amide-hydrolyzing activity. With aliphatic nitriles, a considerably higher specific activity was induced against olefinic aliphatic, heterocyclic and aromatic nitriles.