Taxonomic study of methanol-assimilating yeasts.

Abstract

Thirty-one freshly isolated strains of methanol-assimilating yeasts were identified as Pichia cellobiosa (3 strains), Candida boidinii (20 strains), Candida cariosilignicola (1 strain), Candida succiphila (6 strains), and Torulopsis molischiana (1 strain). Kloeckera sp. No. 2201 and Candida methanolica, which were reported as methanol-assimilating yeasts, and Candida koshuensis were reidentified as C. boidinii on the basis of biological and chemotaxonomic characteristics. Torulopsis methanolovescens showed characteristics similar to those of Pichia lindnerii, and the chemotaxonomic characteristics of the two were in good agreement. The DNA base composition (GC-content of DNA) of these yeasts was distributed in a broad range from 29.2% to 50.2%. The ubiquinone system, proton magnetic resonance spectra of cell-wall mannans, and electrophoretic patterns of methanol oxidase were characteristic for each species. These methanol-assimilating yeasts were divided into four groups: 1) the C. boidinii group, 2) methanol-assimilating Hansenula and its closely related yeasts, 3) the P. cellobiosa group, and 4) the Hansenula capsulata group.