Chionosphaera pinicorticola sp. nov., a novel basidiomycetous yeast species isolated from pine tree bark in Gyeongju, South Korea.

A novel yeast species, isolated from the bark of pine trees in Gyeongju, South Korea, and designated as KCTC 37304T (ex-type KACC 410729), is characterized by its genetic, morphological and physiological properties. Molecular phylogenetic analysis involving the D1/D2 domain of the 26S LSU rRNA gene and the internal transcribed spacer (ITS) region confirms that it belongs to the genus Chionosphaera. In comparison to Chionosphaera cuniculicola CBS:10065, the type strain of its closest relative, KCTC 37304T exhibits 8 nucleotide substitutions (~2.07%) in the D1/D2 domain and 54 substitutions (~8.47%) in the ITS region. Morphologically, cells of KCTC 37304T are globose to ovoid, which distinguishes them from the cylindrical cells of C. cuniculicola. Physiologically, KCTC 37304T does not assimilate methanol or ethanol but can utilize succinate and xylitol, further differentiating it from C. cuniculicola. Based on these distinctive genetic, morphological and physiological features, we propose the new species Chionosphaera pinicorticola sp. nov., with KCTC 37304T (ex-type strain KACC 410729) designated as the holotype.