Derxomyces taiwanicus 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 taiwanicus Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828779. Fig. 10C, D .

Etymology: the specific epithet taiwanicus refers to the geographic origin of the type strain, Taiwan.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal and cylindrical, 3.0 –3.7 × 4.4 – 8.2 μm and single, budding is polar ( Fig. 10C ), 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 pale-yellow, 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 are ellipsoidal to napiform, 2.9 – 4.3 × 3.0 – 4.3 μm ( Fig. 10D ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, L-sorbose (delayed and weak), sucrose, maltose, cellobiose, trehalose, melibiose, raffinose, melezitose, D-xylose, L-arabinose, D-arabinose (delayed and weak), D-ribose (delayed and weak), L-rhamnose, ribitol (delayed and weak), galactitol (delayed and weak), D-mannitol, D-glucitol (delayed and weak), Methyl-α- D-glucoside, salicin (delayed and weak) and succinate are assimilated as sole carbon sources. Lactose, inulin, soluble starch, Dglucosamine, methanol, ethanol, glycerol, erythritol, DL-lactate, citrate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate and L-lysine are assimilated as sole nitrogen sources. Potassium nitrate, sodium nitrite, ethylamine hydrochloride and cadaverine dihydrochloride 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. taiwanicus differs from the closely related species De. ovatus in its inability to assimilate myo-inositol ( Table S1.11 ).

Typus: China, Taiwan province, obtained from a leaf of an unidentified plant, Aug. 2009, Q.-M. Wang (holotype CGMCC 2.4429 T preserved in a metabolically inactive state, ex-type CBS 12490 = TW3.1C-02).

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.