Derxomyces melastomatis 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 : 97

Derxomyces melastomatis Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828778. Fig. 10A, B .

Etymology: the specific epithet melastomatis refers to Melastoma , the plant genus from which the type strain was isolated.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ovoid and ellipsoidal, 2.3– 4.0 × 4.7 –8.2 μm and single, budding is polar ( Fig. 10A ), 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 yellowish-cream, butyrous, smooth and dull. 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 are ellipsoidal to napiform, 2.7– 4.0 × 2.9– 5.3 μm ( Fig. 10B ).

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

Typus: China, Wuzhishan mountain , Hainan province, obtained from a leaf Melastoma candidum , Nov. 2006, Q.-M. Wang (holotype CGMCC 2.3459 T preserved in a metabolically inactive state, ex-type CBS 15485 = WZS19.7).

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.