Derxomyces napiformis 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 : 95

Derxomyces napiformis Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828775. Fig. 9K, L .

Etymology: the specific epithet napiformis refers to the napiform ballistoconidia of the type strain.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal to ovoid, 1.5– 4.3 × 5.0–8.6 μm and single, budding is polar ( Fig. 9K ), a sediment is formed. 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 yellowish-cream, butyrous, slightly 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 ellipsoidal to napiform, 2.9– 3.6 × 4.2– 4.6 μm ( Fig. 9L ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, sucrose, maltose, cellobiose, trehalose, melibiose, raffinose, melezitose, D-xylose, Larabinose, D-arabinose, L-rhamnose, Methyl-α- D-glucoside, succinate and myo-inositol are assimilated as sole carbon sources. L-sorbose, lactose, inulin, soluble starch, D-ribose, Dglucosamine, methanol, ethanol, glycerol, erythritol, ribitol, galactitol, D-mannitol, D-glucitol, salicin, DL-lactate, citrate and hexadecane are not assimilated. Ammonium sulfate, L-lysine, 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. napiformis differs from its closely related species De. bifurcus in its inability to assimilate inulin, D-ribose and potassium nitrate and its ability to assimilate Methyl-α- Dglucoside, succinate and myo-inositol ( Table S1.11 ).

Typus: China, Taiwan province, obtained from a leaf of an unidentified plant, Aug. 2009, Q.-M. Wang (holotype CGMCC 2.4446 T preserved in a metabolically inactive state, ex-type CBS 15748 = TW1.1F028).

Figures

Fig. 9. 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) Bu. elongatum CGMCC 2.4428T; (B) De. pseudoboekhoutii CGMCC 2.4436T; (C, D) De. polymorphus CGMCC 2.4437T; (E, F) De. xingshaicus CGMCC 2.2459T; (G, H) De. pseudoyunnanensis CGMCC 2.3563T; (I, J) De. longiovatus CGMCC 2.3535T; (K, L) De. napiformis CGMCC 2.4446T; (M, N) De. bifurcus CGMCC 2.3470T; (O, P) De. elongatus CGMCC 2.3561T. Bars = 10 μm.