Rosettozyma petaloides 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 : 119

Rosettozyma petaloides Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828832. Figs 11G, H and 16A, B .

Etymology: the specific epithet petaloides refers to the vegetative cells forming a petale morphology of the type strain.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are elongate fusiform, either singly or in rosettes, 2.2–3.2 × 9.8 –18.7 μm, budding is polar ( Fig. 16A ), a sediment is formed. After 1 mo at 17 °C, a pellicle and a sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is whitish to cream, butyrous, slightly wrinkled and semi-glossy. 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 cylindrical or falcate, 1.3–1.6 × 9.3–12.0 μm ( Fig. 16B ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, sucrose, maltose, cellobiose (variable), trehalose, lactose (variable), raffinose (variable), melezitose, Dxylose, L-arabinose, D-arabinose (variable), D-ribose (variable), ethanol (variable), glycerol, ribitol (variable), D-mannitol, D-glucitol, Methyl-α- D-glucoside, salicin (delayed and weak), DL-lactate (variable), succinate (delayed and weak) and citrate (delayed and weak) are assimilated as sole carbon sources. Galactose, L-sorbose, melibiose, inulin, soluble starch, L-rhamnose, D-glucosamine, methanol, erythritol, galactitol, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate (variable), sodium nitrite (variable), L-lysine (variable), ethylamine hydrochloride (delayed and weak) and cadaverine dihydrochloride (delayed and weak) are assimilated as sole nitrogen sources. Maximum growth temperature is 26–27 °C. Growth in vitamin-free medium is delayed and weak. 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, Ro. petaloides and its two closely related species, Ro. cystopteridis and Ro. motuoensis , can be distinguished from one another by the assimilation of D-xylose, Larabinose, D-arabinose, glycerol and succinate. Ro. petaloides differs from the other species in its ability to assimilate D-xylose and glycerol ( Table S1.28 ).

Typus: China, Wuzhishan mountain , Hainan province, obtained from a leaf of an unidentified plant, Nov. 2006, Q.-M. Wang (holotype CGMCC 2.3446 T preserved in a metabolically inactive state, ex-type CBS 15480 = WZS29.14).

Figures

Fig. 11. SEM image of vegetative cells grown in YM broth for 5 d at 17 °C. (A) Fi. mali CGMCC 2.4012T, Bars = 4 μm; (B) Boe. sterigmata CGMCC 2.4539T, Bars = 5 μm; (C) St. layueensis CGMCC 2.5817T, Bars = 5 μm; (D) Pse. motuoensis CGMCC 2.5816T, Bars = 2 μm; (E) Me. layueensis CGMCC 2.5818T, Bars = 5 μm; (F) Beg. foliicola CGMCC 2.3164T, Bars = 1 μm; (G, H) Ros. petaloides CGMCC 2.3446T, G Bars = 10 μm, H Bars = 3 μm.

Fig. 16. 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) Ros. petaloides CGMCC 2.3446T; (C, D) Ros. cystopteridis CGMCC 2.2615T; (E, F) Ros. motuoensis CGMCC 2.5819T; (G, H) Sp. cellobiolyticus CGMCC 2.5675T; (I, J) Sp. reniformis CGMCC 2.5627T; (K, L) Sp. ellipsoideus CGMCC 2.5619T; (M, N) Sp. primogenomicus IAM13481T; (O, P) Rh. platycladi CGMCC 2.3118T. Bars = 10 μm.