Pichia wuzhishanensis f. a. S. Hu, L. C. Guo, F. Y. Bai & P. J. Han sp. nov.

Etymology.

The specific epithet wuzhishanensis (wu. zhi. han’en. sis. N. L. fem. adj.) is named after the location where the type strain of the species was isolated: Wuzhishan city, Hainan province, China.

Type.

The holotype CGMCC 2.7381 (original number = HWY 125-2) was isolated from rotten wood of Garcinia mangostana collected from Wuzhishan city, Hainan province, China (18.902 ° N, 109.688 ° E; tropical monsoon oceanic climate) by S. Hu in August, 2023 and had been deposited in a metabolically inactive state in the China General Microbiological Culture Collection Centre (CGMCC), Beijing, China . An ex-type culture had been deposited in the Japan Collection of Microorganisms (JCM), Koyadai, Japan, as JCM 36905. GenBank accessions: ITS - PQ 586093 and LSU - PQ 586303.

Culture characteristics.

After growth on YPD agar for 3 days at 25 ° C, colonies are white, butyrous, circular and glossy, with a smooth surface and entire margins (Fig. 5 A). Cells are oval-shaped or oval (2.1–4.5 × 3.1–5.7 μm) and budding is monopolar (Fig. 5 B). Sexual structures were not observed in single or mixed strain cultures on CMA, PDA and V 8 agar after 2 months of incubation at 25 ° C.

Physiological and biochemical characteristics.

Glucose is not fermented. Glucose, ethanol, N-acetyl-D-glucosamine, glycerol, D-glucosamine, succinic acid and DL-lactic acid (weak) are assimilated as sole carbon sources. D-galactose, L-sorbose, erythritol, D-xylose, glucitol, maltose, sodium citrate dihydrate, cellobiose, trehalose, lactose, melibiose, raffinose, melezitose, soluble starch, L-arabinose, D-arabinose, xylitol, D-ribose, L-rhamnose, methanol, ribitol, galactitol, D-mannitol, α-methyl-D-glucoside, salicin, D-glucuronic acid, inositol, sucrose, inulin and hexadecane are not assimilated as sole carbon sources. Ethylamine hydrochloride, cadaverine dihydrochloride, L-lysine and ammonium sulfate are assimilated as sole nitrogen sources. Sodium nitrite and potassium nitrate are not assimilated as sole nitrogen sources. Growth in vitamin-free medium and on 50 % (w / v) glucose are positive, while growth in 10 % NaCl plus 5 % glucose medium and on 60 % (w / v) glucose are negative. Diazonium blue B, urease activity and production of extracellular starch-like compounds are negative. Growth on YPD agar at 37 ° C is positive, but negative at 42 ° C.

Notes.

Pichia wuzhishanensis is physiologically differentiated from its closely related species Pichia thaimueangensis by its ability to assimilate D-xylose.