TAXONOMIC STUDIES ON DEBARYOMYCES HANSENII (ZOPF) LODDER ET KREGER-VAN RIJ AND RELATED SPECIES.

I. CHEMOTAXONOMIC INVESTIGATIONS

Abstract

Taxonomic studies on Debaryomyces hansenii (ZOPF) Lodder et Kregervan Rij and related yeast species were carried out using chemotaxonomic methods including DNA base composition, DNA-DNA hybridization, ubiquinone system, proton magnetic resonance spectrum of mannan, and serological methods. The 50 strains employed were classified into 3 groups, I, II, and III, based on DNA-DNA hybridization experiments. These groups were considered to represent three distinct species. Group I consisted of two subgroups, Ia and Ib, which were considered to represent two distinct varieties. These groups were also characterized by proton magnetic resonance spectra of alkali-extracted mannans and cell surface antigens, however, they could not be discriminated by DNA base composition and ubiquinone systems, in addition to the taxonomic criteria commonly employed in yeast taxonomy. Group Ia comprised 34 strains including the type or authentic strains of D. hansenii, D. nicotianae, D. nicotianae var. minor, D. kloeckeri, D. kloeckeri var. major, D. tyrocola, D. gruetzii, D. matruchoti, D. matruchoti var. cesarii, D. hildegaardi, D. guilliermondii, D. miso, Torulopsis westerdijkii, T. famata, and T. minor. Group Ib comprised 6 strains including the type or authentic strains Of D. subglobosus, D. fukuyamaensis, Pichia adzetii, and Candida flareri. Group II comprised 4 strains including the type or authentic strains of D. nepalensis, D. cavensis, and D. japonicus. Group III comprised 6 strains including the type strain of T. candida.