Derxomyces pseudoyunnanensis Q.M. Wang, F.Y. Bai & A.H. Li, 2020

Li, A. - H., Yuan, F. - X., Groenewald, M., Bensch, K., Yurkov, A. M., Li, K., Han, P. - J., Guo, L. - D., Aime, M. C., Sampaio, J. P., Jindamorakot, S., Turchetti, B., Inacio, J., Fungsin, B., Wang, Q. - M. & Bai, F. - Y., 2020, Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species, Studies In Mycology 96, pp. 17-140 : 94

Derxomyces pseudoyunnanensis Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828773. Fig. 9G, H .

Etymology: the specific epithet pseudoyunnanensis refers to the similar colony morphology to that of Derxomyces yunnanensis .

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ovoid and ellipsoidal, 1.5–4.3 × 5.7 –10.0 μm and single, budding is polar ( Fig. 9G ), a sediment is formed. After 1 mo at 17 °C, a pellicle and sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is cream,butyrous, wrinkled and dull. The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are globose and subglobosal to napiform, 3.6– 4.4 × 3.6– 5.1 μm ( Fig. 9H ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, L-sorbose (variable), sucrose, maltose, cellobiose, trehalose, melibiose, raffinose, melezitose, inulin, soluble starch (variable), D-xylose, L-arabinose (variable), D-arabinose, D-ribose (variable), L-rhamnose, galactitol (variable), D-mannitol (variable), D-glucitol (variable), Methyl-α- D-glucoside (variable), salicin (variable) and myo-inositol (weak) are assimilated as sole carbon sources. Lactose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, ethanol, glycerol, erythritol, ribitol, DL-lactate, succinate, citrate and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate (variable), L-lysine, ethylamine hydrochloride, cadaverine dihydrochloride are assimilated as sole nitrogen sources. Sodium nitrite is not assimilated. Maximum growth temperature is 28 °C. Growth in vitamin-free medium is variable. Starch-like substances are not produced. Growth on 50 % (w/w) glucose-yeast extract agar is negative. Urease activity is positive. Diazonium Blue B reaction is positive.

Physiologically, De. pseudoyunnanensis can not be distinguished from its close relative De. longiovatus ( Table S1.11 ).

Typus: China, Simao county, Yunnan province, obtained from a leaf of an unidentified plant, Nov. 2006, Q.-M. Wang (holotype CGMCC 2.3563 T preserved in a metabolically inactive state, ex-type CBS 15499 = SM37E2).

Figures

Fig. 9. Vegetative cells grown in YM broth for 5 d at 17 °C and ballistoconidia produced on corn meal agar after 7 d at 17 °C. (A) Bu. elongatum CGMCC 2.4428T; (B) De. pseudoboekhoutii CGMCC 2.4436T; (C, D) De. polymorphus CGMCC 2.4437T; (E, F) De. xingshaicus CGMCC 2.2459T; (G, H) De. pseudoyunnanensis CGMCC 2.3563T; (I, J) De. longiovatus CGMCC 2.3535T; (K, L) De. napiformis CGMCC 2.4446T; (M, N) De. bifurcus CGMCC 2.3470T; (O, P) De. elongatus CGMCC 2.3561T. Bars = 10 μm.