A TAXONOMIC STUDY ON CELLULOLYTIC YEASTS AND YEAST-LIKE MICROORGANISMS ISOLATED IN JAPAN .2. THE GENUS CRYPTOCOCCUS

Seven strains of cellulolytic anamorphic basidiomycetous yeasts isolat ed from natural materials collected in Japan were identified as three species in the genus Cryptococcus; Cryptococcus flavus (1 strain), Cry ptococcus cellulolyticus sp, nov. (5 strains) and Cryptococcus sp. (1 strain). Cr, cellulolyticus resembles Cr, flavus in the taxonomic crit eria traditionally employed for yeasts but is differentiated from this species in DNA-DNA reassociation experiments. Practically, Cv. cellul olyticus is discriminated from Cr. flavus in the assimilation of eryth ritol and the lack of assimilation of ethanol, A strain assigned to Cr yptococcus sp. produces septated mycelium and has Q-9 as the major ubi quinone. These characteristics resemble those of Q-9-equipped strains of Cryptococcus humicolus. However, differences are found in the lack of assimilation of melezitose and in growth without vitamins. We retai ned it as unidentified because Cr, humicolus itself is assumed to be a heterogeneous species and a revision of the species concept is requir ed.