Four new species in Lipomyces

North-to-South diversity of lipomycetaceous yeasts in soils evaluated with a cultivation-based approach from 11 locations in Japan

To understand the species distribution, diversity, and density of lipomycetaceous yeasts in soil based on their north-to-south location in Japan, 1146 strains were isolated from soil samples at 11 locations from Hokkaido to Okinawa Prefecture and taxonomically characterized. Lipomycetaceous yeast strains were isolated efficiently from soil by selecting watery mucoid-like colonies on agar plates with nitrogen-depleted medium. Twenty-four (80%) of the 30 known species of the genus Lipomyces were isolated from the soil samples collected in Japan, including species recently proposed. Among the species isolated, L. starkeyi was the most predominant in Japan, except on Iriomote Island, Okinawa, and accounted for 60-98% of the isolated strains. Lipomyces yarrowii was the dominant species on Iriomote Island (64%). The second most dominant species were L. chichibuensis in Saitama Prefecture and L. doorenjongii from Yamaguchi to Okinawa Prefecture. The species diversity of lipomycetaceous yeasts was in Japan and the significant correlation with the latitude of the sampling sites was revealed.

Lipomyces chichibuensis sp. nov., isolated in Japan, and reidentification of the type strains of Lipomyces kononenkoae and Lipomyces spencermartinsiae

We isolated two strains of a novel Lipomyces species from soil collected in Chichibu forest, Saitama prefecture, Japan. Based on their morphological and biochemical characteristics, along with multilocus sequence typing using the D1/D2 domain of the large-subunit (LSU) rRNA gene, the internal transcribed spacer (ITS) region and the translation elongation factor 1 alpha gene (EF-1α), the two strains were shown to represent a novel species of the genus Lipomyces, described as Lipomyces chichibuensis sp. nov. (type strain CB08-2T = NBRC 109582T = CBS 12929T; Mycobank no. MB808164). In addition, we reidentified the type strains of Lipomyces kononenkoae and Lipomyces spencermartinsiae maintained in culture collections based on phenotypic characters and/or DNA–DNA hybridization to ensure correct future identification of species of the genus Lipomyces. The correct type strains of L. kononenkoae and L. spencermartinsiae are NBRC 107661T ( = CBS 2514T) and NBRC 10376T ( = CBS 5608T), respectively.

Multigene phylogenetic analysis of the Lipomycetaceae and the proposed transfer of Zygozyma species to Lipomyces and Babjevia anomala to Dipodascopsis

Phylogenetic relationships among species assigned to genera of the family Lipomycetaceae were determined from analysis of the nearly entire large, subunit rRNA gene, the small subunit rRNA gene, mitochondrial small subunit rRNA gene and the translation elongation factor-1alpha gene. Monophyly of the Lipomycetaceae was strongly supported, and currently described species appear genetically unique. The multigene analysis provided no support for maintaining the genera Kawasakia, Smithiozyma, Waltomyces or Zygozyma, and it is proposed that species in these genera be assigned to the genus Lipomyces. The monotypic genus Babjevia is a member of the Dipodascopsis clade and it is proposed to reassign Babjevia anomala to Dipodascopsis. The proposed changes will result in the Lipomycetaceae having two ascosporic genera, Lipomyces and Dipodascopsis, and the anamorphic genus Myxozyma.

Lipomyces orientalis sp. nov., a yeast species isolated from soil in Vietnam

Five strains of the novel ascogenous yeast species Lipomyces orientalis sp. nov. were isolated from soil samples collected in Vietnam. The yeast forms asci containing one to four ascospores. The ascospores of L. orientalis have warty surfaces and differ from the characteristic striated ascospores of Lipomyces tetrasporus. Phylogenetic analyses of D1/D2 26S rDNA and ITS sequences indicate that L. orientalis and L. tetrasporus are closely related, but they differ from each other by 6 nucleotides in the D1/D2 region and 16 nucleotides in the ITS region. The type culture is strain Lip 95(T) (=CBS 10300(T)=NRRL Y-27927(T)).