Starmerella elongatum C. Y. Chai & F. L. Hui sp. nov.

Fig. 2 A, B

Etymology.

The specific epithet elongatum refers to the elongate vegetative cells of this yeast.

Type.

Mexico • State of Mexico, Teotihuacan, in the traditional Mexican alcoholic beverage Pulque, autumn of 2015, F. L. Hui, NYNU 16115 (holotype CICC 33262 T preserved in a metabolically inactive state, culture ex-type CBS 15224).

Description.

After 3 days growth in YM broth at 25 ° C, the cells are mostly ellipsoidal to elongate (2.2–3.4 × 3.9–7.3 μm) and occurred singly or in pairs. Budding is multilateral (Fig. 2 A). Sediment is formed after one month, but no pellicle is observed. After 6 days culture on YM agar at 25 ° C, colonies are white-cream in color, butyrous, smooth, and convex with complete margins. After 2 weeks in Dalmau plate culture on corn meal agar at 25 ° C, pseudohyphae are present, but no true hyphae are observed (Fig. 2 B). Asci or signs of conjugation are not seen on sporulation media. Glucose, sucrose, raffinose, and inulin (weakly) are fermented, while trehalose, galactose, maltose, melibiose, lactose, cellobiose, melezitose, methyl α - D-glucoside, soluble starch, or xylose are not. Glucose, sucrose (weakly), raffinose (weakly), inulin (weakly) and soluble starch (weakly) are assimilated. No growth occurred using as sole carbon source of melibiose, galactose, lactose, L-sorbose, L-rhamnose, L-arabinose, D-arabinose, D-ribose, methanol, ethanol, erythritol, galactitol, myo - inositol, DL-lactate, D-gluconate, xylitol, D-glucuronate, D-glucono- 1, 5 - lactone, L-arabinitol, trehalose, maltose, melezitose, methyl α - D-glucoside, cellobiose, salicin, D-xylose, glycerol, ribitol, mannitol, glucitol, succinate, citrate, D-glucosamine, 2 - keto-D-gluconate, arbutin, or 5 - keto-D-gluconate. With respect to the assimilation of nitrogen compounds, L-lysine (weakly), cadaverine (weakly) and D-tryptophan (weakly) were assimilated, whereas nitrate, nitrite, ethylamine, creatine, creatinine, glucosamine and imidazole were not assimilated. Growth is observed at 30 ° C but not at 35 ° C. Growth is observed in the presence of 10 % NaCl plus 5 % glucose, 1 % acetic acid, and vitamin-free medium, but not in the presence of 0.1 % cycloheximide or 0.01 % cycloheximide. Starch-like compounds are not produced. Urease activity and diazonium blue B reactions are also negative.

Additional strains examined.

Mexico • Teotihuacan in the State of Mexico (19°41'N, 98°50'W), in the traditional Mexican alcoholic beverage Pulque samples, autumn of 2015, F. L. Hui, NYNU 161124, and NYNU 161128.

GenBank accession numbers.

Holotype CICC 33262 T (ITS: MF 136069, D 1 / D 2: MF 136061); additional strains NYNU 161124 (ITS: OM 669948, D 1 / D 2: OM 669942) and NYNU 161128 (ITS: OM 669943, D 1 / D 2: OM 670017).

Note.

Starmerella elongatum sp. nov. can be physiologically differentiated from their nearest phylogenetic neighbor, S. stellata (Krumbholz 1931), on the basis of their ability to grow in the presence of 10 % NaCl plus 5 % glucose, 1 % acetic acid, and vitamin-free medium, and their ability to assimilate inulin, soluble starch, and cadaverine (Table 2).

[a] Data from Foschino et al. (2004); [b, c] Data from Imanishi et al. (2007); [d] Data from Nisiotou and Nychas (2008); [e] Data from Rybářová et al. (1980); [f] Data from Kurtzman et al. (2008). +, Positive; -, negative; w, weakly positive; s, slow positive; d, delayed positive; v, variable.