Cystobasidium raffinophilum 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 : 116

Cystobasidium raffinophilum Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828822. Fig. 15M .

Etymology: the specific epithet raffinophilum refers to the ability to assimilate raffinose.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal, 3.1–5.0 × 4.5 –6.8 μm and single, budding is polar ( Fig. 15M ), a sediment is present. After 1 mo at 17 °C, a ring and sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is orange-pink, mucoid,smooth and glistening.The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are not produced.

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose (delayed), sucrose, cellobiose, trehalose, raffinose, melezitose, inulin (weak), D-xylose, Larabinose, D-arabinose, D-ribose (delayed and weak), ethanol, glycerol, ribitol (delayed and weak), galactitol, D-mannitol, succinate (weak) and citrate (weak) are assimilated as sole carbon sources. L-sorbose, maltose, lactose, melibiose, soluble starch, Lrhamnose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, erythritol, D-glucitol, Methyl-α- D-glucoside, salicin, DL-lactate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate and potassium nitrate are assimilated as sole nitrogen sources. Sodium nitrite, L-lysine, ethylamine hydrochloride and cadaverine dihydrochloride are not assimilated. Maximum growth temperature is 26–27 °C. Growth in vitamin-free medium is negative. 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, Cy. raffinophilum differs from its closely related species Cy. fimetarium in its inability to assimilate lactose, salicin, DL-lactate and its ability to assimilate galactose, raffi- nose, melezitose, galactitol and potassium nitrate ( Table S1.26 ).

Typus: China, Yecheng county, Xinjiang province, obtained from soil, Jul. 2007, Q.-M. Wang (holotype CGMCC 2.3822 T preserved in a metabolically inactive state, ex-type CBS 15509 = 141.4).

Figures

Fig. 15. 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, B) Phy. aceris CGMCC 2.2662T; (C) Phy. jiayinensis CGMCC 2.5669T; (D) Me. layueensis CGMCC 2.5818T; (E) Sa. melibiophila CBS 5143T; (F) Mi. ellipsoideus CGMCC 2.5664T; (G, H) Mi. rubellus CGMCC 2.4444T; (I, J) Mi. pseudomagnisporus CGMCC 2.4538T; (K, L) Sy. rhododendri CGMCC 2.2613T; (M) Cy. raffinophilum CGMCC 2.3822T; (N) Cy. terricola CGMCC 2.3823T, (O) Do. ningxiaensis CGMCC 2.4451T; (P) Beg. foliicola CGMCC 2.3164T. Bars = 10 μm.