Teunia siamensis f.a., sp. nov., a novel tremellaceous yeast species isolated from soil in a secondary peat swamp forest area

The strain DMKU-XD44, representing an anamorphic novel yeast species, was isolated from soil collected in a peat swamp forest (PSF) area in Rayong Botanical Garden in eastern Thailand. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, Teunia cuniculi CBS 10309T was the most closely related species. The novel species differed from the T. cuniculi type by 2.5 % (14 nucleotide substitutions) in the D1/D2 region of the LSU rRNA gene and by 8.0 % (40 nucleotide substitutions) in the ITS region. The results of a phylogenetic analysis, based on the combined sequences of the ITS region and the D1/D2 region, indicated that DMKU-XD44 represents a member of the Teunia clade in the Cryptococcaceae (Tremellales, Tremellomycetes, Agaricomycotina and Basidiomycota) and is phylogenetically distinct from other species of the genus Teunia in the clade. Therefore, DMKU-XD44 represents a novel species of the genus Teunia. The name Teunia siamensis f.a., sp. nov. is proposed. The holotype is DMKU-XD44, while the MycoBank number is MB 832816.