Derxomyces ovatus 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 : 98

Derxomyces ovatus Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828780. Fig. 10E, F .

Etymology: the specific epithet ovatus refers to the ovoid vegetative cells of the type strain.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ovoid or ellipsoidal, 2.0– 5.4 × 3.8– 7.7 μm and single, budding is polar ( Fig. 10E ), a sediment is present. After 1 mo at 17 °C, a ring and a sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is yellow, butyrous, smooth 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 ellipsoidal to napiform, 1.8 –3.6 × 3.0–4.5 μm ( Fig. 10F ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, L-sorbose (delayed and weak), sucrose, maltose, cellobiose, trehalose, melibiose, raffinose, melezitose, inulin (delayed and weak), soluble starch (weak), D-xylose, Larabinose, L-rhamnose, ethanol (delayed and weak), galactitol, Dmannitol, D-glucitol, Methyl-α- D-glucoside, salicin (delayed and weak), succinate and myo-inositol are assimilated as sole carbon sources. Lactose, D-arabinose, D-ribose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, glycerol, erythritol, ribitol, DL-lactate, citrate and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate (delayed and weak) and L-lysine are assimilated as sole nitrogen sources. Sodium nitrite, ethylamine hydrochloride and cadaverine dihydrochloride are not assimilated. Maximum growth temperature is 28 °C. Growth in vitamin-free medium is netative. 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. ovatus differs from the closely related species De. taiwanicus . in its ability to assimilate myo-inositol ( Table S1.11 ).

Typus: China, Simao county, Yunnan province, obtained from a leaf of an unidentified plant, Nov. 2006, Q.-M. Wang (holotype CGMCC 2.3572 T preserved in a metabolically inactive state, ex-type CBS 15654 = SM32.2).

Figures

Fig. 10. 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) De. melastomatis CGMCC 2.3459T; (C, D) De. taiwanicus CGMCC 2.4429T; (E, F) De. ovatus CGMCC 2.3572T; (G, H) De. longicylindricus CGMCC 2.5660T;; (I) Pha. lactea CGMCC 2.5810T; (J) Pha. ovata CGMCC 2.5614T; (K, L) Ho. saccardoi CGMCC 2.3445T; (M) So. gelidoterrea CGMCC 2.5814T; (N) Fi. dingjieense CGMCC 2.5649T, (O) Fi. globosum CGMCC 2.5680T; (P) Fi. mali CGMCC 2.4012T. Bars = 10 μm.