Shinya Ninomiya

Three new species of bipolar budding yeasts of the genus Hanseniaspora and its anamorph Kloeckera isolated in Thailand

In the course of a survey of yeast biodiversity in the natural substrates in Thailand, eight strains were found to represent three hitherto undescribed species of Hanseniaspora/Kloeckera. They were isolated from insect frass, flower, lichen, rotted fruit and rotted wood. Based on the morphological and physiological characteristics, and sequences of D1/D2 domain, six strains represent a single species of the genus Hanseniaspora, described as Hanseniaspora thailandica sp. nov. (type BCC 14938(T)=NBRC 104216(T)=CBS 10841(T)), and another strain as Hanseniaspora singularis sp. nov. (type BCC 15001(T)=NBRC 104214(T)=CBS 10840(T)). A further strain, which belongs to Kloeckera and does not produce ascospores, is described as Kloeckera hatyaiensis sp. nov. (type BCC 14939(T)=NBRC 104215(T)=CBS 10842(T)). Strains belonging to H. thailandica sp. nov. differed by 17-19 nucleotide substitutions from Hanseniaspora meyeri, the closest species. DNA reassociation between the two taxa showed 30-48% relatedness. Kloeckera hatyaiensis sp. nov. and H. singularis sp. nov. differed by eight and 16 nucleotide substitutions with one gap from the nearest species, Hanseniaspora clermontiae and Hanseniaspora valbyensis, respectively.

Two novel ascomycetous yeast species, Wickerhamomyces scolytoplatypi sp. nov. and Cyberlindnera xylebori sp. nov., isolated from ambrosia beetle galleries

Thirteen strains of yeasts were isolated from ambrosia beetle galleries at several sites in Japan. Based on the morphological and biochemical characteristics and phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene of the yeasts, 10 strains were shown to represent a novel species of the genus Wickerhamomyces, described as Wickerhamomyces scolytoplatypi sp. nov. (type strain NBRC 11029(T) = CBS 12186(T)), and were closely related to Wickerhamomyces hampshirensis. The three other strains represented a novel species of the genus Cyberlindnera, described as Cyberlindnera xylebori sp. nov. (type strain NBRC 11048(T) = CBS 12187(T)), and were closely related to Cyberlindnera euphorbiiphila. It is suggested that these species are associated with ambrosia beetles and we consider ambrosia beetle galleries as good sources of novel yeasts.

Yamadazyma kitorensis f.a., sp. nov. and Zygoascus biomembranicola f.a., sp. nov., novel yeasts from the stone chamber interior of the Kitora tumulus, and five novel combinations in Yamadazyma and Zygoascus for species of Candida

Analysis of D1/D2 large-subunit (LSU) rRNA gene sequences predicted that 17 yeast isolates, mainly from viscous gels (biofilms) taken from the stone chamber interior of the Kitora tumulus in Nara, Japan, were placed in the Yamadazyma and Zygoascus clades. Polyphasic characterization, including morphological, physiological and chemotaxonomic characteristics, multigene sequence divergence and DNA-DNA hybridization, strongly suggested the assignment of one novel species to each of the clades; these are Yamadazyma kitorensis f.a., sp. nov., with the type strain JCM 31005T (ex-type CBS 14158T=isolate K8617-6-8T), and Zygoascus biomembranicola f.a., sp. nov., with the type strain JCM 31007T (ex-type CBS 14157T=isolate K61208-2-11T). Furthermore, the transfer of five known species of the genus Candida as novel combinations to the genera Yamadazyma and Zygoascus is proposed; these are Yamadazyma olivae f.a., comb. nov. (type strain CBS 11171T=ATCC MYA-4568T), Yamadazyma tumulicola f.a., comb. nov. (type strain JCM 15403T=ex-type CBS 10917T=isolate T6517-9-5T), Yamadazyma takamatsuzukensis f.a., comb. nov. (type strain JCM 15410T=CBS 10916T = isolate T4922-1-1T), Zygoascus polysorbophila f.a., comb. nov. (type strain NRRL Y-27161T=CBS 7317T) and Zygoascus bituminiphila f.a., comb. nov. (type strain CBS 8813T=MUCL 41424T).

Candida nonsorbophila sp. nov., a new ascomycetous yeast species isolated in Thailand

Four yeast strains, RS42, SSK10, ST-520 and ST-521, isolated from water in a mangrove forest, bark of a tree and fruit of Ficus sp., respectively, were found to represent a hitherto undescribed anamorphic species. The four strains are related to Candida sinolaborantium in the D1/D2 domain of the large subunit rRNA gene, but differed by eight nucleotide substitutions and two indels, and for this reason are regarded as members of a separate species. Because ascospore formation was not detected, it is described as a new species of Candida, Candida nonsorbophila sp. nov. The type strain is RS42(T) (BCC 25963(T)=NBRC 103860(T)=CBS 10862(T)). This species is distinguished from C. sinolaborantium by the inability to assimilate L-sorbose, L-rhamnose and galactitol, and a higher maximum growth temperature.

Vanderwaltozyma verrucispora sp. nov., a new ascomycetous yeast species

A new yeast species, Vanderwaltozyma verrucispora, is proposed in this study based on two strains isolated from partially decayed leaves in Japan and one strain from soil in Taiwan. The species is characterized by the fermentation of glucose and galactose, formation of one to four spheroidal to ellipsoidal ascospores with warty surfaces in each ascus, and assimilation of a few carbon and nitrogen compounds. Genus assignment and distinction of the species from the other two recognized species of Vanderwaltozyma is based on the morphological and physiological characteristics, and phylogenetic analysis of nucleotide sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene. From these comparisons, the name V. verrucispora sp. nov. is proposed. Sequence analysis of the D1/D2 domains of the LSU rRNA gene reveals that the phylogenetically closest relative of V. verrucispora is Vanderwaltozyma yarrowii. The type strain of the new species, which was isolated from a partially decayed leaf in Kagoshima Prefecture, Japan, is NBRC 1884(T) (=CBS 10887(T)=BCRC 23141(T)).