Title: MULTIGENE PHYLOGENETIC ANALYSIS OF THE TRICHOMONASCUS, WICKERHAMIELLA AND ZYGOASCUS YEAST CLADES, AND THE PROPOSAL OF SUGIYAMAELLA GEN. NOV. AND FOURTEEN NEW SPECIES COMBINATIONS Authors
Submitted to: Federation Of European Microbiological Societies Yeast Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 13, 2006
Publication Date: January 15, 2007
Citation: Kurtzman, C.P., Robnett, C.J. 2007. Multigene phylogenetic analysis of the Trichomonascus, Wickerhamiella and Zygoascus yeast clades, and the proposal of Sugiyamaella gen. nov. and fourteen new species combinations. Federation Of European Microbiological Societies Yeast Research. 7:141-151. Interpretive Summary: Yeasts assigned to the genera Arxula, Blastobotrys, Stephanoascus and Sympodiomyces grow on chemical compounds not utilized by most other yeasts and therefore have potential for biotechnology and bioremediation. These species were compared from multiple gene sequences and found to be members of a single group despite being classified in several different genera. In this work, the species were reclassified into genetically defined genera, which also resulted in description of a new genus and discovery of 21 new species. Major benefits from this work are that the new names are predictive of the biochemistry of the groups, and the new species are likely to be of biotechnological importance.
Technical Abstract: Relationships among species assigned to the ascosporic yeast genera Sporopachydermia, Stephanoascus, Trichomonascus, Wickerhamiella and Zygoascus, and to the associated anamorphic genera Arxula, Blastobotrys, Sympodiomyces and Trigonopsis, were determined from phylogenetic analyses of gene sequences from the nearly complete large subunit rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II. The genus Stephanoascus is polyphyletic resulting in reassignment of two species to the older genus Trichomonascus and the third to Sugiyamaella gen. nov. (type species S. smithiae). The genera Sporopachydermia, Wickerhamiella and Zygoascus appear monophyletic. The species Pichia ofunaensis and P. tannicola are proposed for transfer to Zygoascus. Arxula, Blastobotrys and Sympodiomyces are members of the Trichomonascus clade with the genus Blastobotrys having taxonomic priority for anamorphic states. Trigonopsis variabilis and three species of Candida represent a distinct clade. From the foregoing gene sequence analyses, the new genus Sugiyamaella is proposed as are 14 new species combinations and the new family Trichomonascaceae.