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-di gesting alpha-amylase, xylanase, and polygalacturonase. The fermentati on ability was negative, and D.B.B., urease, and DNase tests were posi tive. The major ubiquinone was Q-10 and the mol% G+C content of nuclea r DNA was 67. The cells were oval to ellipsoidal; no true mycelium, ps eudomycelium, or teliospores were observed; and it contained a large a mount of xylose (19.7 mol%) in the whole-cell hydrolyzates. From these characters, strain S-2 was assigned to the genus Cryptococcus.