Derxomyces pseudoboekhoutii 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 : 93

Derxomyces pseudoboekhoutii Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828770. Fig. 9B .

Etymology: the specific epithet pseudoboekhoutii refers to the similar colony morphology to that of Derxomyces boekhoutii .

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal or ovoid, 2.5 –3.8 × 5.0– 7.5 μm and single, budding is polar ( Fig. 9B ), 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 cream, butyrous and semi-glossy. 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 not produced.

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, galactose, sucrose, maltose, cellobiose, trehalose, melibiose, raffinose, melezitose, inulin, Dxylose, L-arabinose, D-arabinose, D-ribose (delayed), galactitol (weak), D-mannitol (delayed and weak) and Methyl-α- D-glucoside are assimilated as sole carbon sources. L-sorbose, lactose, soluble starch, L-rhamnose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, ethanol, glycerol, erythritol, ribitol, Dglucitol, salicin, DL-lactate, succinate, citrate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate, L-lysine, ethylamine hydrochloride (delayed and weak), cadaverine dihydrochloride (delayed and weak) are assimilated as sole nitrogen sources. Sodium nitrite is not assimilated. Maximum growth temperature is 25 °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. pseudoboekhoutii differs from the closely related species De. boekhoutii in its inability to assimilate soluble starch and grow in vitamin-free medium and its ability to assimilate D-arabinose and D-ribose ( Table S1.11 ).

Typus: China, Fuzhou county, Fujian province, obtained from a leaf of an unidentified plant, Aug. 2011, Q.-M. Wang (holotype CGMCC 2.4436 T preserved in a metabolically inactive state, ex-type CBS 12493 = FJYZ12-8).

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.