Diddensiella luoyangensis C.Y. Chai & F.L. Hui, 2022

Chai, Chun-Yue, Gao, Wan-Li, Yan, Zhen-Li & Hui, Feng-Li, 2022, Four new species of Trichomonascaceae (Saccharomycetales, Saccharomycetes) from Central China, MycoKeys 90, pp. 1-18 : 1

Diddensiella luoyangensis C.Y. Chai & F.L. Hui sp. nov.

Fig. 2

Etymology.

The specific epithet luoyangensis refers to the geographic origin of the type strain: Luoyang City, Henan.

Type.

China, Henan Province, Luoyang City, Song County, the Tianchi Mountain National Forest Park , in rotting wood, October 2020, J.Z. Li & Z.T. Zhang (holotype NYNU 201062T, ex-type CBS 16659 = CICC 33512, holotype and ex-type are preserved in a metabolically inactive state) .

Description.

In YM broth after 3 days at 25 °C, cells are ovoid (2-3 × 3-5 μm) and occur singly or in pairs. Budding is multilateral. Sediment is formed after a month, but a pellicle is not observed. On YM agar after 3 days at 25 °C, colonies are white to cream- coloured, convex, butyrous, and smooth with entire margins. In Dalmau plate culture on corn meal agar, pseudohyphae and true hyphae are formed. Asci or signs of conjugation are not observed on sporulation media. Fermentation of sugars is absent. Glucose, galactose, l-sorbose, glucosamine, d-ribose, d-xylose, l-arabinose, d-arabinose, l-rhamnose, sucrose, maltose, trehalose, methyl α- d-glucoside, cellobiose, salicin, melibiose, lactose, raffinose, melezitose, inulin, glycerol, erythritol, ribitol, d-glucitol, d-mannitol, galactitol, myo -inositol, d-glucono-1, 5-lactone, 2-keto-d-gluconate, 5-keto-d-gluconate, d-gluconate, d-glucuronate, dl-lactate succinate, citrate, and ethanol are assimilated as sole carbon sources. Methanol is not assimilated. l-lysine, creatine, glucosamine, and d-tryptophan are assimilated as sole nitrogen sources, while nitrate, nitrite, ethylamine, cadaverine, creatinine, and imidazole are not assimilated. Minimum growth temperature is 15 °C, and maximum growth temperature is 37 °C. Growth in the presence of 0.1% cycloheximide is present, but growth in the presence of 10% NaCl plus 5% glucose and 1% acetic acid is absent. Starch-like compounds are not produced. Urease activity and diazonium blue B reactions are negative.

Additional isolate examined.

China, Henan Province, Luoyang City, Song County, the Tianchi Mountain National Forest Park, in rotting wood, October 2020, J.Z. Li & Z.T. Zhang (NYNU 201074).

Notes.

Two strains were collected from two different substrates, representing D. luoyangensis , clustered in the Diddensiella clade which is sister to species D. transvaalensis . D. luoyangensis differed from D. transvaalensis by 1.6% substitutions in the D1/D2 domain. Furthermore, we were unable to align the ITS sequence of D. luoyangensis with the D. transvaalensis type strain, because the ITS sequence of D. transvaalensis is not currently available from either the NCBI GenBank or CBS databases. Physiologically, D. luoyangensis differs from its closely related species, D. transvaalensis ( Lachance et al. 2011), based on growth in l-rhamnose, lactose, inulin, d-gluconate and growth at 37 °C, which are present for D. luoyangensis and absent for the latter species. Moreover, D. transvaalensis ferments glucose and galactose, while this new species does not.

Figures

Figure 2. Morphology of D. luoyangensis (NYNU 201062, holotype) A budding cells were indicated by arrows in YM broth after 3 d B pseudohyphae and true hyphae on CM agar after 14 d. Scale bars: 10 μm.