DESCRIPTION OF SAVITREEA PENTOSICARENS SAKPUNTOON, ANGCHUAN, BOONMAK, KHUNNAMWONG, JACQUES, GRONDIN, CASAREGOLA & SRISUK SP. NOV.
MycoBank number: MB 835044; Index Fungorum number: IF 835044; Facesoffungi number: FoF;
Savitreea pentosicarens (pen.to.si.ca′rens. N.L. neut. n. pentosum L. pres. part. carens lacking; N.L. part. adj. pentosicarens lacking the ability to utilize pentose). Growth occurs in YM broth. After 3 days at 25 °C, cells are ellipsoid (2.5–5.0×3–7.5 µm). Colonies are white to cream, convex and butyrous, with a dull surface and undulate margins (Fig. 2). Pseudohyphae are observed on PDA at 25 °C after 3 days (Fig. 2). Ascospores are not found in individual cultures or in mixed cultures on PDA, YM agar, YPD agar, corn meal agar, 5% malt extract agar, Gorodkowa agar, Fowell’s acetate agar and YCBAS medium after 8 weeks at 25 °C. Glucose is fermented, but galactose, maltose, sucrose, trehalose, melibiose, lactose, raffinose and xylose are not. Glucose, sorbose, maltose, sucrose, trehalose, melizitose (slow), inulin (slow), starch (weak), d-glucitol, inositol (slow), d-mannitol, glycerol, ethanol, methanol (weak), citric acid, lactic acid, succinic acid (slow), d-gluconic acid, d-glucuronic acid, d-glucono-1,5-lactone, 2-ketogluconic acid and 5-ketogluconic acid (weak) are assimilated as the sole carbon sources, while galactose, cellobiose, lactose, melibiose, raffinose, d-arabinose, l-arabinose, d-ribose, l-rhamnose, d-xylose, galactitol, erythritol, ribitol, d-galacturonic acid, methyl α-d-glucoside and salicin are not assimilated. Ammonium sulphate, potassium nitrate (weak), sodium nitrite (weak) and l-lysine (slow) are utilized as sole nitrogen sources, while ethylamine hydro- chloride and cadaverine dihydrochloride are not utilized. Growth on a vitamin-free medium is negative. No growth occurs in media containing 50% (w/v) glucose and 10% (w/v) sodium chloride/5% (w/v) glucose. Growth at 30 and 35 °C are positive for strain DMKU-GTCP10-8, but negative at 35 °C for strain CLIB 1740. Growth is not observed in the presence of 0.01% (w/v) and 0.1% (w/v) cycloheximide. Acid production is positive, while urease and DBB reactions are negative.
The holotype, DMKU-GTCP10-8, was isolated from a grease trap in Bangkok, Thailand and is permanently preserved in a metabolically inactive state at the Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand. An ex-type culture has been deposited in the collection of the Portuguese Yeast Culture Collection (PYCC), Caparica, Portugal, as strain PYCC 8490, and in the Thailand Bioresource Research Centre (TBRC), Thailand as strain TBRC 12159. The MycoBank number for Savitreea pentosicarens sp. nov. is MB 835044. The GenBank/ EMBL/DDBJ accession numbers for the SSU rRNA gene, ITS region, the D1/D2 domain of the LSU rRNA gene, TEF1 gene and RPB2 gene sequences determined in this study are MN966870, MN977919, MN966866, MT165633 and MT165635 for DMKU-GTCP10-8 and MN966869, MN977918, MN966867, MT165632 and MT165634 for CLIB 1740, respectively.
Fig. 2. Morphology of Savitreea pentosicarens DMKU-GTCP10-8T. (a) Budding cells in YM broth after incubated at 25 °C for 3 days; (b) pseudohyphae formed on PDA at 25 °C for 3 days. Bars, 10 µm.