Oxidation of amines by yeasts grown on 1-aminoalkanes or putrescine as the sole source of carbon, nitrogen and energy.

The maximum growth rate of Trichosporon cutaneum CBS 8111 in chemostat cultures was 0.185 h-1 on ethylamine and 0.21 h-1 on butylamine, that of Candida famata CBS 8109 was 0.32 h-1 on putrescine. The amine oxidation pattern of the ascomycetous strains studied, viz. Candida famata CBS 8109, Stephanoascus ciferrii CBS 4856 and Trichosporon adeninovorans CBS 8244 was independent of the amine that had been used as the growth substrate. It resembled that of benzylamine/putrescine oxidase found in other ascomycetous yeasts. However, differences in pH optimum and substrate specificity were observed between the amine-oxidizing systems of these three species. The amine oxidation pattern of cell-free extracts of Trichosporon cutaneum CBS 8111 varied with the amine that was used as growth substrate. The enzyme system produced by Cryptococcus laurentii CBS 7140 failed to oxidize isobutylamine and benzylamine, and showed a high pH optimum. The synthesis of amine oxidase in the four yeast strains studied was not repressed by ammonium chloride and was weakly repressed by glucose but was strongly repressed if both compounds were present in the growth medium.