RESUMEN
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 (2.5-2.9â%) and 28-50 (5.4-8.8â%) 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 (1.5-2.8â%) and 45-53 (8.2-9.6â%) 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.
Asunto(s)
Agaricales , Ascomicetos , Saccharomycetales , Filogenia , Tailandia , Agaricales/genética , ADN Espaciador Ribosómico/genética , Análisis de Secuencia de ADN , Composición de Base , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Ácidos Grasos/química , Ascomicetos/genética , Nucleótidos , ADN de Hongos/genética , Técnicas de Tipificación MicológicaRESUMEN
Two strains of genus Kodamaea, representing a novel anamorphic yeast species, were isolated from two samples of Marasmiellus sp. collected in Thailand. Analysis of the sequences of the internal transcribed spacer (ITS) regions and the D1/D2 domains of the large subunit (LSU) rRNA gene showed that the two strains differed by 27-42 nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 7-34 nucleotide substitutions in the ITS region of a group of related species, Kodamaea smagusa CBS 11430T, Kodamaea fungicola JCM 10142T, Kodamaea plutei ATCC MYA-4329T, Kodamaea lidongshanica SD5S01T and Kodamaea jinghongensis NYNU 167162T. Phylogenetic analysis based on the concatenated sequences of the ITS and the D1/D2 domains of the LSU rRNA gene showed that the two strains were placed in the Kodamaea clade and clearly separated from other recognized species of the genus. Therefore, the two strains were assigned as a novel species of the genus Kodamaea, for which we propose the name Kodamaea samutsakhonensis f.a., sp. nov. The holotype is TBRC 16043T (=DMKU-BP19T) and the isotype is PYCC 9354. The MycoBank number of the novel species is MB 846490.
