Ogataea kanchanaburiensis sp. nov. and Ogataea wangdongensis sp. nov., two novel methylotrophic yeast species from phylloplane in Thailand.

Three strains (KM03(T), KM13 (T) and KM15) representing two novel methylotrophic yeast species were isolated from the external surface of plant leaves, which were collected from Kanchanaburi province, Thailand, by three-consecutive enrichments in methanol broth. Strain KM03(T) was isolated from phylloplane of a mango tree (Mangifera indica) and two strains, KM13(T) and KM15, were obtained from phylloplane of different wine grapes (Vitis vinifera). The sequences of the D1/D2 region of the large subunit (LSU) rRNA gene of the two strains (KM13(T) and KM15) were identical and differed markedly from that of strain KM03(T). In terms of pairwise sequence similarity of the D1/D2 region the closest species to the strains KM13(T) and KM15 were Candida suzukii (CBS 9253(T)) and Candida nitratophila (CBS 2027(T)) but with 2.1 % nucleotide substitutions. Strain KM03(T) differed from Ogataea wickerhamii (CBS 4307(T)), its closest relative, by 2.3 % nucleotide substitutions. Phylogenetic analysis based on the D1/D2 sequences placed the three strains in the Ogataea clade. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analyses of the D1/D2 and the internal transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene (nrRNA) operon, the three strains represent two novel Ogataea species although formation of ascospores was not observed. Ogataea kanchanaburiensis sp. nov. is proposed for strain KM03(T) (=BCC 47626(T) = NBRC 108603(T) = CBS 12673(T)). Two strains, KM13(T) and KM15, were assigned to Ogataea wangdongensis sp. nov. (type strain KM13(T) = BCC 42664(T) = NBRC 107778(T) = CBS 12674(T)). GenBank/EMBL/DDBJ accession numbers for the sequences of the D1/D2 and the ITS regions of O. kanchanaburiensis KM03(T) are AB734090 and AB734093, respectively, of O. wangdongensis KM13(T) are AB734091 and AB734094, respectively, and of O. wangdongensis KM15 are AB734092 and AB734095, respectively.