Yunzhangomyces sedi sp. nov., a basidiomycetous yeast species isolated from phylloplane.

Abstract

Two yeast strains, CICC 33533 and NYNU 26815, belonging to the basidiomycetous yeast genus Yunzhangomyces, were isolated from the leaf surfaces of Sedum aizoon and Sorbus alnifolia, respectively, collected in the Baotianman Nature Reserve, Henan Province, China. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene, together with detailed phenotypic characterization, indicated that these two strains, along with an additional strain NRP040 isolated from a plant in Japan, represent a novel asexual species of the genus Yunzhangomyces in the order Exobasidiales. The name Yunzhangomyces sedi sp. nov. (MycoBank MB 863876) is, therefore, proposed with strain CICC 33533 designated as the holotype. The novel species differs from its closely related species, Yunzhangomyces orchidis, Yunzhangomyces clavatus, Yunzhangomyces cylindricus, Yunzhangomyces nandinae and Yunzhangomyces scirpi by 24-32 nucleotide substitutions (4.2-5.7%) in the D1/D2 domain. In the ITS region, the novel species also exhibited more than 23 nucleotide mismatches (6.4%) from Y. orchidis, Y. clavatus, Y. cylindricus and Y. nandinae. The ITS sequence of Y. scirpi was not available for comparison. Minor physiological differences were also observed: the novel species was able to assimilate galactitol, thereby differentiating it from the closely related yeast-like species Y. orchidis, Y. clavatus, Y. cylindricus and Y. nandinae.