Wickerhamiella verensis f.a. sp. nov., a novel yeast species isolated from subsoil groundwater contaminated with hydrocarbons and from a human infection

Yeast strains belonging to a novel anamorphic yeast species were isolated from subsoil groundwater contaminated with hydrocarbons in a metal working factory located in northern Spain, and from a human infection in the USA. Comparison of ITS sequences between the isolates revealed 0.2 % divergence between the Spanish isolates and 0.46 % divergence between those and the USA isolate. Phylogenetic analysis based on the D1/D2 domains of the LSU rRNA gene showed that these isolates belong to the Wickerhamiella clade with W. sorbophila and W. infanticola as their closest relatives. Sequence divergence between the new isolates and W. sorbophila and W. infanticola was 1.97 and 1.79 %, respectively. The isolates in the novel species are not fermentative and pseudohyphae were not produced. Sexual reproduction was not observed for individual isolates or in mixtures of isolates. Conjugation between the isolates in the novel species and close relatives W. sorbophila and W. infanticola was not observed. These data support the proposal of Wickerhamiella verensis as a novel species, with CECT 12028T as the holotype.

Morph-molecular characterization of Meira nicotianae sp. nov., a novel basidiomycetous, anamorphic yeast-like fungus associated with growth improvement in tobacco plant

A novel yeast-like species was isolated from the rhizosphere of tobacco root collected in Guizhou province, China. Sequence analysis of the large subunit (LSU) rDNA gene indicates that the isolate represents a novel species and most closely related to Meira siamensis. The phylogenetic analysis based on the Internal Transcribed Spacer (ITS) rDNA gene also confirmed the placement of the novel species within Meira. However, the novel species differs from M. siamensis by 9.1% bp difference in the LSU rDNA sequence region and also in terms of physiological characteristics as compared to other species. This species is proposed as M. nicotianae sp. nov. Co-incubation of M. nicotianae strain CY-1 and tobacco plantlets demonstrates that this fungal strain can promote growth of tobacco plant. Scanning electron micrographs and other morphological illustrations along with phylogenies are presented in this paper.

Description of Diutina gen. nov., Diutina siamensis, f.a. sp. nov., and reassignment of Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida ranongensis, Candida rugosa and Candida scorzettiae to the genus Diutina

Three strains (DMKU-RE28, DMKU-RE43T and DMKU-RE123) of a novel anamorphic yeast species were isolated from rice leaf tissue collected in Thailand. DNA sequence analysis demonstrated that the species forms a sister pair with Candida ranongensis CBS 10861T but differs by 24–30 substitutions in the LSU rRNA gene D1/D2 domains and 30–35 substitutions in the ITS region. A phylogenetic analysis based on both the small and the large rRNA gene subunits confirmed this connection and demonstrated the presence of a clade that also includes Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida rugosa and Candida scorzettiae. The clade is not closely affiliated to any known teleomorphic genus, and forms a well-separated lineage from currently recognized genera of the Saccharomycetales. Hence, the genus Diutina gen. nov. is proposed to accommodate members of the clade, including Diutina siamensis f.a. sp. nov. and the preceding seven Candida species. The type strain is DMKU-RE43T ( = CBS 13388T = BCC 61183T = NBRC 109695T).

Hannaella phyllophila sp. nov., a basidiomycetous yeast species associated with plants in Thailand and Taiwan

Five strains representing one novel anamorphic yeast species were isolated from plant leaves collected in Thailand (strains DMKU-SP186T, ST-111 and ST-201) and Taiwan (strains FN20L02 and SM13L16). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were assigned to a single novel species of the genus Hannaella. The sequences of the D1/D2 regions of the LSU rRNA genes of four of the strains (DMKU-SP186T, ST-111, FN20L02 and SM13L16) were identical, while differing from strain ST-201 by 2 substitutions and 2 gaps. The nucleotide sequence of the ITS regions of the five strains differed from each other by between 0 and 3 nucleotide substitutions. The novel species was most closely related to Hannaella luteola, but showed 1.0–1.3 % nucleotide substitutions (between 6 substitutions out of 568–606 nt and 8 substitutions, and 2 gaps out of 597 nt) in the D1/D2 region of the LSU rRNA gene and 1.4–2.0 % nucleotide substitutions (6–9 substitutions out of 435 nt) in the ITS region. Ballistospores were produced by three of the strains on cornmeal agar at 15 and 20 °C after 4 weeks, while H. luteola did not produce ballistospores. The name Hannaella phyllophila sp. nov. is proposed. The type strain is DMKU-SP186T ( = BCC 69500T = NBRC 110428T = CBS 13921T).

Hannaella siamensis sp. nov. and Hannaella phetchabunensis sp. nov., two new anamorphic basidiomycetous yeast species isolated from plants

Eight strains, representing two novel anamorphic yeast species, consisted of five strains isolated from the external surfaces of rice leaves (DMKU-RP72T, DMKU-RP109, DMKU-RP119, YE-124 and YE-156) and one from a corn leaf (DMKU-CP430T)4 collected in Thailand, and one strain isolated from each of a composite flower (11-1114) and a fallen dead leaf (12-301); the latter two were collected in Belize. On the basis of sequence analysis of the D1/D2 region of the large subunit rRNA gene and the internal transcribed spacer (ITS) region, they were suggested to be two novel species of the genus Hannaella. Seven strains (DMKU-RP72T, DMKU-RP109, DMKU-RP119, YE-124, YE-156, 11-1114 and 12-301) differed from each other by 0–3 nt substitutions in the D1/D2 region and by 0–1 nt substitutions in the ITS region. In terms of pairwise sequence similarities of the D1/D2 region these seven strains were closest to Hannaella zeae, but with 1.2–1.7 % (7–9) nucleotide substitutions. The sequences of the ITS region of these seven strains differed from H. zeae by 3.7–3.9 % (16–17) nucleotide substitutions. Therefore, they were assigned to a single novel species and the name Hannaella siamensis sp. nov. has been proposed. The type strain is DMKU-RP72T ( = BCC 69493T = NBRC 110425T = CBS 13533T). Strain DMKU-CP430T represents the second novel species and was also most closely related to H. zeae, but with 1.0 % (6) nucleotide substitutions in the D1/D2 region and 3.2 % (14) nucleotide substitutions in the ITS region. It was assigned to the proposed novel species, Hannaella phetchabunensis sp. nov. (type strain DMKU-CP430T = BCC 69492T = NBRC 110424T = CBS 13386T).

Wickerhamomyces mori sp. nov., an anamorphic yeast species found in the guts of wood-boring insect larvae

A novel anamorphic yeast species is described to accommodate three isolates recovered from the guts of three different wood-boring insect larvae collected in Henan, central China. On the basis of sequence analyses of the D1/D2 domains of the large-subunit rRNA gene and the internal transcribed spacer regions, the three strains are assigned to a novel species of the genus Wickerhamomyces, although the formation of ascospores was not observed. These strains also exhibited a number of distinct morphological and physiological characteristics that clearly differentiated them from Wickerhamomyces mucosus, Candida odintsovae and Wickerhamomyces rabaulensis, the most closely related species. In view of the phenotypic differences and unique rRNA gene sequences, we consider that these three isolates represent a novel species of the genus Wickerhamomyces, Wickerhamomyces mori sp. nov. The type strain is NYNU 1216T ( = CICC 1983T = CBS 12678T).