Two yeast strains representing two novel yeast species were isolated from frass of an unidentified insect (ST-78T) and the external surfaces of rice leaves (YE170T) collected in Thailand. The two strains were genetically, morphologically and phenotypically distinct from recognized species and were found to represent two novel species of the genus Yamadazyma although formation of ascospores was not observed. In terms of pairwise sequence similarity of the D1/D2 region of the large subunit rRNA gene, the closest relative of strain ST-78T was Candida lessepsii CBS 9941T but with 3.8 % nucleotide substitutions, while the closest relative of strain YE170T was strain ST-78T but with 4.3 % nucleotide substitutions. Analysis of the sequences of the internal transcribed spacer 1 and 2 (ITS1–2) regions revealed that strain ST-78 differed from C. lessepsii CBS 9941T by 8.8 % nucleotide substitutions and from strain YE170T by 9.4 % nucleotide substitutions. The result of pairwise sequence similarity of the D1/D2 and ITS1–2 regions together with phylogenetic analysis indicated that strains ST-78T and YE170T represented two novel species within the Yamadazyma clade. The names Yamadazyma insecticola f.a., sp. nov. (type strain ST-78T = BCC 8314T = NBRC 110421T = CBS 13382T; MycoBank no. MB810546) and Yamadazyma epiphylla f.a., sp. nov. (type strain YE170T = BCC 63466T = NBRC 110423T = CBS 13384T; MycoBank no. MB810547) are proposed for the two novel yeast species.
Eight strains, representing two novel anamorphic yeast species, consisted of five strains isolated from the external surfaces of rice leaves (DMKU-RP72T, DMKU-RP109, DMKU-RP119, YE-124 and YE-156) and one from a corn leaf (DMKU-CP430T)4 collected in Thailand, and one strain isolated from each of a composite flower (11-1114) and a fallen dead leaf (12-301); the latter two were collected in Belize. On the basis of sequence analysis of the D1/D2 region of the large subunit rRNA gene and the internal transcribed spacer (ITS) region, they were suggested to be two novel species of the genus Hannaella. Seven strains (DMKU-RP72T, DMKU-RP109, DMKU-RP119, YE-124, YE-156, 11-1114 and 12-301) differed from each other by 0–3 nt substitutions in the D1/D2 region and by 0–1 nt substitutions in the ITS region. In terms of pairwise sequence similarities of the D1/D2 region these seven strains were closest to Hannaella zeae, but with 1.2–1.7 % (7–9) nucleotide substitutions. The sequences of the ITS region of these seven strains differed from H. zeae by 3.7–3.9 % (16–17) nucleotide substitutions. Therefore, they were assigned to a single novel species and the name Hannaella siamensis sp. nov. has been proposed. The type strain is DMKU-RP72T ( = BCC 69493T = NBRC 110425T = CBS 13533T). Strain DMKU-CP430T represents the second novel species and was also most closely related to H. zeae, but with 1.0 % (6) nucleotide substitutions in the D1/D2 region and 3.2 % (14) nucleotide substitutions in the ITS region. It was assigned to the proposed novel species, Hannaella phetchabunensis sp. nov. (type strain DMKU-CP430T = BCC 69492T = NBRC 110424T = CBS 13386T).
Seven strains representing a novel yeast species belonging to the genus Kazachstania were found at several collection sites on both mainland Ecuador (Yasuní National Park) and the Galápagos (Santa Cruz Island). Two strains (CLQCA 20-132T and CLQCA 24SC-045) were isolated from rotten wood samples, two further strains (CLQCA 20-280 and CLQCA 20-348) were isolated from soil samples, and three strains (CLQCA 20-198, CLQCA 20-374 and CLQCA 20-431) were isolated from decaying fruits. Sequence analyses of the D1/D2 domains of the LSU rRNA gene and ribosomal internal transcribed spacer (ITS) region indicated that the novel species is most closely related to Kazachstania servazzii and Kazachstania unispora. Although the strains could not be distinguished from one another based upon their differing geographical origins, they could be differentiated according to their isolation source (fruit, soil or wood) by ITS sequencing. The species name Kazachstania yasuniensis sp. nov. is proposed to accommodate these strains, with CLQCA 20-132T ( = CBS 13946T = NCYC 4008T) designated the type strain.