The Phylogenetic Relationships of Methanol - assimilating Yeasts Based on Sequences of 18 S and 26 S Ribosomal RNAs : The Proposal of Komagataella ( Saccharomycetaceae ) t

Twelve strains of methanot-assimi}ating yeast species were examined for their partial base sequences of 18S and 26S rRNAs. In the partial base sequencings of 18S rRNA (positions 1451-1618, 168 bases), P. kodomae had the same partial base sequence as Qgataea minuta, and P. finlandica, P. pini, P. trehatophila, CL maris, and CL methanolovescens were the same in the partial base sequences as O. glaeoevma. Cbndida boidinii and C: metltytica were similar to O. gincoryma, but somewhat different from O. minuta (the base difflerences, one and four, respectiyely). Pichia naganishii had seyen, four, six, and nine base differences with O. minuta, O. gincoevma, P. anomala, and P. membranaef}iciens, respectiyely, and C: methanosorbosa did four, three, fiye, and twelye base differences. Piehia pastoris was quite different (the base differences among the methanol-assimilating yeasts, 32-31), and no bases were found in the fingerprint segment. In the partial base sequencings of 26S rRNA (positions 1611-1835, 225 bases; positions 493-622, 130 bases), P. finlandica, P. kodomae, P. pini, P. trehalophila, C maris, CL methanolovescens, and C methanosorhosa were similar to O. minuta and O. gincoryma. Pichia naganishii, C boidinii, and C: metdytica had somewhat different partial base sequences. The base differences and the percent simi}arities of P. pastoris were quite high (101-89) and quite low (40-47). Based on the sequence data obtained, the methanol-assimilating yeast species are discussed taxonomically and phylogenetically. A new genus, Kbmagataella was proposed for P. pastoris with a new combination, Kbmagataella pastoris.