Zygoascus detingensis 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

Zygoascus detingensis C.Y. Chai & F.L. Hui sp. nov.

Fig. 5

Etymology.

The specific epithet detingensis refers to the geographic origin of the type strain, Deting Town, 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 201087 T, ex-type CBS 16667 = CICC 33516, holotype and ex-type preserved in a metabolically inactive state) .

Description.

In YM broth after 3 days at 25 °C, cells are subglobosal to globosal (2-3 × 2-4 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 cream, smooth, opalescent, convex and glistening. 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 (weak), glucosamine, d-ribose (weak), d-xylose, d-arabinose (weak), l-arabinose (weak), l-rhamnose (weak), sucrose (weak), maltose (weak), trehalose, methyl α-d-glucoside (weak), cellobiose (weak), salicin, melibiose, lactose (weak), raffinose, melezitose (weak), inulin (weak), glycerol (weak), erythritol, ribitol (weak), xylitol (weak), d-glucitol (weak), d-mannitol (weak), galactitol (weak), myo -inositol (weak), d-glucono-1, 5-lactone, 2-keto-d-gluconate, d-gluconate (weak), d-glucuronate (weak), dl-lactate (weak), succinate (weak), and ethanol are assimilated as sole carbon sources. l-sorbose, citrate, and methanol are not assimilated. Ethylamine, glucosamine, and l-lysine are assimilated as sole nitrogen sources. Nitrate, nitrite, cadaverine, creatine, creatinine, imidazole, and d-tryptophan 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 201011).

Notes.

Two strains were collected from two different substrates, both representing Z. detingensis , branched separately from the Zygoascus clade. Z. detingensis differed from the other Zygoascus species by more than 9.7% substitutions in the D1/D2 domain and 11.5% substitutions in the ITS region, respectively. Physiologically, Z. detingensis differs from its closely related species, Z. bituminiphila (V. Robert, B. Bonjean, Karutz, Paschold, W. Peeters & Wubbolts) Nagatsuka, Kiyuna & Sugiyama ( Nagatsuka et al. 2016), in its inability to assimilate l-sorbose and its ability to assimilate l-rhamnose, methyl α-d-glucoside, melibiose, lactose, inulin melezitose, erythritol, and 2-keto-d-gluconate. Moreover, Z. bituminiphila ferments glucose, galactose, trehalose, and cellobiose, while Z. detingensis does not.

Figures

Figure 5. Morphology of Z. detingensis (NYNU 201087, 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.