The Phylogeny of Williopsis salicorniae HINZELIN, KURTZMAN et SMITH Based on the Partial Sequences of 18S and 26S Ribosomal RNAs (Saccharomycetaceae)

Abstract

Williopsis salicorniae IFO 10733 (type strain), which is characterized by the formation of saturn-shaped ascospores, by the incapability of assimilating nitrate, and by a lower DNA base composition (36.7 mol% G + C), was examined for its partial base sequences of 18S and 26S rRNAs. In the 18S rRNA partial base sequencings, it had an identical base sequence with the type strain of Ogataea glucozyma ( ≡ Pichia glucozyma, ≡ Hansenula glucozyma), which produces hat-shaped ascospores and has the ability to assimilate nitrate and methanol and a higher DNA base composition (45.1 mol% G + C). In the 26S rRNA partial base sequencings, the base differences were four, and the percent similarity was 87 between the type strains of the two species. The data obtained are discussed phylogenetically and taxonomically.