Lindnera wuzhiensis sp. nov., a novel ascomycetous yeast species.

Recently, phylogenetic relationships among species assigned to the genera Pichia, Issatchenkia and Williopsis were re-analyzed by using multigene sequence analysis. The concepts of related genera were consequently revised and three new genera Barnettozyma, Lindnera and Wickerhamomyces were proposed (Kurtzman et al., 2008). The genus Lindnera was established to accommodate the Pichia species in the Pichia anomala clade (Kurtzman, 2000; Kurtzman et al., 2008). During our investigation of ascomycetous yeast diversity distribution in plant materials from Hainan Province in China, one strain, YSHM21CT, isolated from a leaf of herbaceous plant was revealed to represent a novel Lindnera species by phenotypic characterization and sequence analyses of the 26S rDNA D1/ D2 domain and internal transcribed spacer (ITS) region. A complete description of the species is given in the present study. Samples of leaves were placed into acidifi ed YPD broth containing 1% yeast extract, 2% peptone, 2% dextrose and 200 μg/ml chloramphenicol, adjusted to pH 4.0‒ 4.5 with HCl. After incubation at room temperature (about 25°C) for 12‒ 24 h, aliquots (100 μl) of the 10-1 or 10-3 diluted cultures were spread on malt extract plates. After 2 days’ incubation at room temperature or 25°C, colonies with different morphological characters were transferred onto malt extract agar slants for further purifi cation and examination. The morphological, physiological and biochemical characteristics were examined according to standard methods commonly used in yeast taxonomy (Yarrow, 1998). Assimilation of nitrogen compounds was investigated on solid media with starved inocula (Nakase and Suzuki, 1986). Nuclear DNA was extracted by the method of Makimura et al. (1994). The DNA fragment covering the ITS region (including 5.8S rDNA) and the large-subunit rDNA D1/D2 domain was amplifi ed and sequenced as described previously (Lu et al., 2004). Molecular phylogenetic analysis was performed by the methods described by Bai et al. (2002). Reference sequences were retrieved from GenBank under the accession numbers indicated in the tree. Phylogenetic analysis from the large subunit (26S) rRNA gene D1/D2 domain sequence showed that strain YSHM21CT was most closely related to Lindnera veronae and Lindnera fabianii (Fig. 1), two species formerly assigned to Pichia (Kurtzman, 2000; Kurtzman et al., 2008). The species in Lindnera were clustered together by analysis of either the individual gene section of the 26S rDNA D1/D2 domain or three concatenated gene sequences from large and small subunit J. Gen. Appl. Microbiol., 56, 409‒412 (2010)