Abstract
Detailed taxonomic studies were made of thirty-five strains of psychrophilic yeasts with large ballistospores. These strains were isolated from dead leaves of Oryza sativa, Miscanthus sinensis, and Sasa sp. in Japan and were found to comprise a single, hitherto undescribed species of the genus Bullera. The species is described here as Bullera megalospora Nakase et Suzuki. Bullera megalospora resembles Bullera piricola and Sporobolomyces puniceus, but it can be distinguished from B. piricola by its inability to assimilate lactose, melibiose, and inositol, and from Sp. puniceus in its lack of assimilation of inositol. Electrophoretic comparison of ten enzymes clearly demonstrated the differences among these three yeasts at the specific level; the similarities in their enzyme patterns were below 22%. Sporobolomyces puniceus was considered to be more closely related to B. megalospora and B. piricola than any of the other species of the genus Sporobolomyces. We propose to transfer this species to the genus Bullera as Bullera punicea (Komagata et Nakase) Nakase et Suzuki comb. nov.