Yamadazyma cocois f.a., sp. nov., an ascomycetous yeast isolated from coconuts

Yamadazyma thunbergiae sp. nov., a novel yeast species associated with Bengal clock vines and soil in Okinawa, Japan

Two strains, designated JCM 36746T and JCM 36749, were isolated from Bengal clock vine (Thunbergia grandiflora) and soil, respectively, in Okinawa, Japan. Analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the large subunit rRNA gene sequences revealed identical sequences in both strains, indicating that they belong to the same species. Sequence analysis and physiological characterization identified these strains as representing a novel yeast species in the genus Yamadazyma. The sequence similarities of the concatenated ITS regions and D1/D2 domains indicated that JCM 36746T and JCM 36749 formed a well-supported distinct from closely related species belonging to the Yamadazyma clade, including Candida dendronema, C. diddensiae, C. germanica, C. kanchanaburiensis, C. naeodendra, C. vaughaniae, Y. akitaensis, Y. koratensis, Y. nakazawae, Y. philogaea, Y. phyllophila, Y. siamensis, Y. ubonensis, and three undescribed species, comprising Candida aff. naeodendra/diddensiae Y151, Candida sp. GE19S08, and Yamadazyma sp. strain NYNU 22830. The sequences of the D1/D2 domains and ITS regions differed in nucleotide substitutions by 1.51% and 2.57% or greater, respectively, from those of the previously described and undescribed related species. In addition, the physiological characteristics of the novel species were distinct from those of the closely related described species. On the basis of these findings, we propose the name Yamadazyma thunbergiae sp. nov. to classify this species within the genus Yamadazyma. The holotype used is JCM 36746T (ex-type strains CBS 18614 and NBRC 116657). The MycoBank accession number is MB 853823.

Yamadazyma sisaketensis f.a., sp. nov. and Yamadazyma koratensis f.a., sp. nov., two novel ascomycetous yeast species from mushrooms and cocoa leaves in Thailand, and reassignment of Candida andamanensis, Candida jaroonii and Candida songkhlaensis to the genus Yamadazyma

Six strains representing two novel ascomycetous yeast species were isolated from mushroom fruiting bodies and cocoa leaves collected in Thailand. Analysis of the internal transcribed spacer (ITS) regions and the D1/D2 domains of the large subunit rRNA gene sequences showed that the six strains were divided into two groups. The first group consisted of four strains (DMKU-SSK46, DMKU-SK1, SCCL3-5 and SCCL19-3), that were closely related to the type strains of Candida conglobata, Candida insectorum, Yamadazyma dushanensis, Yamadazyma mexicana and Yamadazyma riverae, but with 12-14 (2.5-2.9 %) and 28-50 (5.4-8.8 %) nucleotide substitutions in the D1/D2 domains and the ITS regions, respectively. However, two strains (DMKU-KMY40 and DMKU-KO18) of the second group differed from a group of described species, Candida diddensiae, Candida dendronema, Candida germanica, Candida kanchanaburiensis, Candida naeodendra, Candida vaughaniae and Yamadazyma siamensis by 8-15 (1.5-2.8 %) and 45-53 (8.2-9.6 %) nucleotide substitutions in the D1/D2 domains and the ITS regions, respectively. Phylogenetic analysis based on the concatenated sequences of the ITS regions and D1/D2 domains showed that these strains represented two species of the Yamadazyma clade that were distinct from the other related species. Based on the phylogenetic analysis and phenotypic characteristics, these six strains were assigned to two novel species of the genus Yamadazyma, although formation of ascospores was not observed. Yamadazyma sisaketensis f.a., sp. nov., is proposed for the first group (four strains). The holotype is TBRC 17139T (ex-type culture: PYCC 9797). The MycoBank number is MB 849637. Yamadazyma koratensis f.a., sp. nov. is proposed for the second group (two strains). The holotype is TBRC 14868T (ex-type culture: PYCC 8907). The MycoBank number is MB 849638. In addition, it is proposed that Candida andamanensis, Candida jaroonii and Candida songkhlaensis are reassigned to the genus Yamadazyma as Yamadazyma andamanensis comb. nov., Y. jaroonii comb. nov. and Y. songkhlaensis comb. nov., respectively.

New species of Yamadazyma from rotting wood in China

Yamadazyma is one of the largest genera in the family Debaryomycetaceae (Saccharomycetales, Saccharomycetes) with species mainly found in rotting wood, insects and their resulting frass, but also recovered from flowers, leaves, fruits, tree bark, mushrooms, sea water, minerals, and the atmosphere. In the present study, several strains obtained from rotting wood in Henan and Yunnan Provinces of China were isolated. Based on morphology and a molecular phylogeny of the rDNA internal transcribed spacer region (ITS) and the D1/D2 domain of the large subunit (LSU) rDNA, these strains were identified as three new species: Yamadazymaluoyangensis, Y.ovata and Y.paraaseri; and three previously described species, Y.insectorum, Y.akitaensis, and Y.olivae. The three new species are illustrated and their morphology and phylogenetic relationships with other Yamadazyma species are discussed. Our results indicate a high undiscovered diversity of Yamadazyma spp. inhabiting rotting wood in China.