title: Torulaspora quercuum sp. nov. and Candida pseudohumilis sp. nov., novel yeasts from human and forest habitats.
abstract: Strains XZ-46A, XZ-105, XZ-129 and XZ-281(T) isolated from the oral cavities of healthy Tibetan volunteers were revealed to represent two novel ascomycetous yeast species by molecular taxonomic characterizations. Strain XZ-281(T) was most closely related to Candida humilis, but differed from the type strain of the species by eight (1.2%) substitutions in the 26S rRNA gene D1/D2 domain and by >100 (>20%) mismatches in the internal transcribed spacer (ITS) region. Strains XZ-46A, XZ-105 and XZ-129 had identical or similar D1/D2 and ITS sequences with each other and with strain 17YF(T) isolated from a leaf of an oak tree (Quercus sp.). The closest relative of this group was Torulaspora microellipsoides. They differed from the type strain of the species by five (0.9%) substitutions in the D1/D2 domain and >70 (>15%) mismatches in the ITS region. A sexual state was observed in strain 17YF(T), but not in the other four oral strains. An anamorphic name Candida pseudohumilis sp. nov. is proposed for strain XZ-281(T) (=AS 2.3956(T)=CBS 11404(T)) and a teleomorphic name Torulaspora quercuum sp. nov. is proposed for strain 17YF(T) (=AS 2.3768(T)=CBS 11403(T)) and the other three oral strains.
authors.affiliation: Systematic Mycology and Lichenology Laboratory, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Qi-Ming
authors.initials: QM
authors.lastname: Wang
authors.forename: Jianping
authors.initials: J
authors.lastname: Xu
authors.forename: Huamin
authors.initials: H
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Feng-Yan
authors.initials: FY
authors.lastname: Bai
mesh_terms: D002175:Candida / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D017753:Ecosystem; D020459:Genes, rRNA; D006801:Humans; D008297:Male; D008853:Microscopy; D008969:Molecular Sequence Data; D009055:Mouth / Q000382:microbiology*; D010802:Phylogeny; D029963:Quercus / Q000382:microbiology*; D012331:RNA, Fungal / Q000235:genetics; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D017422:Sequence Analysis, DNA; D018609:Tibet; D055319:Torulaspora / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D014197:Trees
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012331:RNA, Fungal; D012339:RNA, Ribosomal, 28S