Derxomyces longiovatus 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 : 94-95

Derxomyces longiovatus Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828774. Fig. 9I, J .

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

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are long ovoid, cylindrical and ellipsoidal, 1.8– 3.7 × 3.9– 13.8 μm and single, budding is polar ( Fig. 9I ), a sediment is formed. After 1 mo at 17 °C, a pellicle and sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is yellowish-cream, butyrous, dull. The margin is entire or eroded. In Dalmau plate culture on corn meal agar, pseudohyphae and hyphaeare formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are subglobosal to napiform, 3.2–4.5 × 4.8– 6.5 μm ( Fig. 9J ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, sucrose, maltose, cellobiose (delayed and weak), trehalose, melibiose, raffinose, melezitose, inulin, soluble starch, D-xylose, L-arabinose, Darabinose, L-rhamnose (delayed and weak), salicin (delayed and weak) and myo-inositol (weak) are assimilated as sole carbon sources. L-sorbose, lactose, D-ribose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, ethanol, glycerol, erythritol, ribitol, galactitol, D-mannitol, D-glucitol, Methyl-α- D-glucoside, DLlactate, succinate, citrate and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate, L-lysine, ethylamine hydrochloride, cadaverine dihydrochloride are assimilatedas sole nitrogen sources. Sodium nitrite is 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. longiovatus and its closely related species De. pseudoyunnanensis as well as De. yunnanensis are very similar. The two new species are not distinguishable, they differ from De. yunnanensis in its ability to assimilate inulin ( Table S1.11 ).

Typus: China, Simao county, Yunnan province, obtained from a leaf of an unidentified plant, Nov. 2006, Q.-M. Wang (holotype CGMCC 2.3535 T preserved in a metabolically inactive state, ex-type CBS 15659 = SM35.4) .

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.