Kockiozyma gen. nov., for Zygozyma suomiensis: the phylogeny of the Lipomycetaceous yeasts

Abstract

In phylogenetic trees based on 18S rRNA gene, 26S rRNA gene, mitochondrial small subunit rRNA gene and the EF-1α gene sequences, and the concatenated sequences of the latter four regions derived from the neighbor-joining method, the four species of the genus Zygozyma constituted four clusters, respectively, with low bootstrap values. In phylogenetic trees based on the concatenated sequences of 18S rRNA genes, 26S rRNA genes, mitochondrial small subunit rRNA genes and the EF-1α genes derived from the neighbor-joining method, the maximum parsimony method and the maximum likelihood method, Lipomyces species including Lipomyces starkeyi (the type species of the genus Lipomyces), Lipomyces tetrasporus and so on, Lipomyces lipofer (= Waltomyces lipofer), Lipomyces japonicus (= Smithiozyma japonica), Babjevia anomala (= Lipomyces anomalus) and Dipodascopsis uninucleata constituted their own respective clusters. The four species of the genus Zygozyma, viz., Zygozyma oligophaga (the type species of the genus Zygozyma), Zygozyma suomiensis, Zygozyma arxii (= Kawasakia arxii) and Zygozyma smithiae (= Limtongia smithiae) were separated from one another and phylogenetically independent from other Lipomycetaceous yeast species. From the data obtained, all four species of the genus Zygozyma were distinguished from one another at the generic level. The name of Kockiozyma was newly suggested for Zygozyma suomiensis, and Kockiozyma suomiensis was introduced as a new combination.