- Volume 64, Issue Pt_11, 2014

In a taxonomic study of yeasts recovered from nectar of flowers and associated insects in South Africa, 11 strains were found to represent two novel species. Morphological and physiological characteristics and sequence analyses of the large-subunit rRNA gene D1/D2 region, as well as the actin, RNA polymerase II and elongation factor 2 genes, showed that the two novel species belonged to the genus Metschnikowia. Metschnikowia drakensbergensis sp. nov. (type strain EBD-CdVSA09-2T = CBS 13649T = NRRL Y-63721T; MycoBank no. MB809688; allotype EBD-CdVSA10-2A = CBS13650A = NRRL Y-63720A) was recovered from nectar of Protea roupelliae and the beetle Heterochelus sp. This species belongs to the large-spored Metschnikowia clade and is closely related to Metschnikowia proteae, with which mating reactions and single-spored asci were observed. Metschnikowia caudata sp. nov. (type strain EBD-CdVSA08-1T = CBS 13651T = NRRL Y-63722T; MycoBank no. MB809689; allotype EBD-CdVSA57-2A = CBS 13729A = NRRL Y-63723A) was isolated from nectar of Protea dracomontana, P. roupelliae and P. subvestita and a honeybee, and is a sister species to Candida hainanensis and Metschnikowia lopburiensis. Analyses of the four sequences demonstrated the existence of three separate phylotypes. Intraspecies matings led to the production of mature asci of unprecedented morphology, with a long, flexuous tail. A single ascospore was produced in all compatible crosses, regardless of sequence phylotype. The two species appear to be endemic to South Africa. The ecology and habitat specificity of these novel species are discussed in terms of host plant and insect host species.

The morphology and morphogenesis of a soil hypotrichous ciliate, Deviata parabacilliformis sp. nov., isolated from northern China, were investigated. D. parabacilliformis measures about 75–210×25–60 µm in vivo, with an elongate and flexible body. It possesses one right marginal row, two to four left marginal rows and three dorsal kineties. The main morphogenetic features of D. parabacilliformis are: (i) the oral primordium originates de novo; (ii) anlage IV of the opisthe originates from parental frontoventral row V, anlage V originates de novo, and anlage VI forms from frontoventral row VI; and (iii) anlage I of the proter originates from the anterior portion of the parental paroral, anlage II originates from the buccal cirrus, anlage III originates from the parabuccal cirri, anlage IV originates from parental frontoventral row IV and anlage V forms from the anterior of parental frontoventral row VI. The morphology of an edaphic population of another species of the genus Deviata, Deviata bacilliformis (Gelei 1954) Eigner 1995, was also investigated. This work also provides the first record of SSU rRNA gene sequences for species of the genus Deviata. Molecular phylogenetic analysis suggests that Deviata is not monophyletic, and its position is poorly resolved due to weak phylogenetic signal of the 18S marker in the Stichotrichida.

Six strains representing a novel yeast species were isolated from tissue (DMKU-SE106T, DMKU-SE110, DMKU-SE112 and DMKU-SE132) and the external surface (DMKU-SP335 and DMKU-SP406) of sugar cane leaves collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region, the six strains were found to represent a single novel species of the genus Wickerhamiella although the formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the six strains differed from each other by 0–2 and 2–3 nt substitutions, respectively. The novel species was related most closely to Candida infanticola but with 4.5–4.6 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and 6.6–7.1 % nucleotide substitutions in the ITS region. The name Wickerhamiella siamensis f.a., sp. nov. is proposed. The type strain is DMKU-SE106T ( = BCC 61185T = NBRC 109697T = CBS 13331T).

Two strains representing Wickerhamiella allomyrinae f.a., sp. nov. were isolated from the gut of Allomyrina dichotoma (Coleoptera: Scarabeidae) collected from the Baotianman National Nature Reserve, Nanyan, Henan Province, China. Sequence analyses of the D1/D2 domains of the LSU rRNA gene revealed that this novel species was located in the Wickerhamiella clade (Saccharomycetes, Saccharomycetales), with three described species of the genus Candida, namely Candida musiphila, Candida spandovensis and Candida sergipensis, as the most closely related species. The novel species differed from these three species by 9.3–9.8 % sequence divergence (35–45 nt substitutions) in the D1/D2 sequences. The species could also be distinguished from the closely related species, C. musiphila, C. spandovensis and C. sergipensis, by growth on vitamin-free medium and at 37 °C. The type strain is Wickerhamiella allomyrinae sp. nov. NYNU 13920T ( = CICC 33031T = CBS 13167T).