ISOLATION AND CHARACTERIZATION OF A YEAST CRYPTOCOCCUS SP S-2 THAT PRODUCES RAW STARCH-DIGESTING ALPHA-AMYLASE, XYLANASE, AND POLYGALACTURONASE

We isolated a yeast from air, strain S-2, which produces raw starch-digesting alpha-amylase, xylanase, and polygalacturonase. The fermentation ability was negative, and D.B.B., urease, and DNase tests were positive. The major ubiquinone was Q-10 and the mol% G+C content of nuclear DNA was 67. The cells were oval to ellipsoidal; no true mycelium, pseudomycelium, or teliospores were observed; and it contained a large amount of xylose (19.7 mol%) in the whole-cell hydrolyzates. From these characters, strain S-2 was assigned to the genus Cryptococcus.