Mrakia panshiensis R.R. Jia & F.L. Hui, 2020

Zhang, Kai-Hong, Shi, Cheng-Feng, Chai, Chun-Yue & Hui, Feng-Li, 2020, Mrakia panshiensis sp. nov. a new member of the Cystofilobasidiales from soil in China, and description of the teleomorphic-stage of M. arctica, MycoKeys 74, pp. 75-90 : 75

Mrakia panshiensis R.R. Jia & F.L. Hui sp. nov. Fig. 2

Etymology.

The species name panshiensis (N.L. fem. adj.) refers to the geographical origin of the type strain of this species.

Description.

The physiological profiles of the three strains of the novel species were almost identical. In YM broth after 3 days at 15 °C, the cells are ovoid to elongated (3.5-7 × 3.5-5 µm) and proliferate by polar budding (Fig. 2A ). Streak culture for 1 week at 15 °C on YM agar produces colonies that are white to yellowish-cream, round, convex and smooth with an entire margin. After 2 weeks in Dalmau plate culture on CM agar at 15 °C, pseudohyphae and true hyphae are formed. Teliospores were observed after 2 months at 10 °C terminally and intercalarily on the hyphae on CM agar (Fig. 2B ). Teliospores are spherical, 8-13 µm in diameter, single and in short chains of 2-4 spores (Fig. 2C ). Teliospores may germinate by a bud-like projection (Fig. 2D ). The fermentation of sugars is absent. Glucose, galactose, l-sorbose, d-ribose, d-xylose, l-arabinose, l-rhamnose, sucrose, maltose, trehalose, methyl α-d-glucoside, cellobiose, salicin, arbutin, melibiose, lactose, raffinose, melezitose, inulin, glycerol, erythritol, ribitol, xylitol, l-arabinitol, d-glucitol, d-mannitol, galactitol, 2-keto-d-gluconate, d-gluconate, d-glucuronate, succinate, citrate and ethanol are assimilated. No growth occurs in d-glucosamine, d-arabinose, myo -inositol, d-glucono-1, 5-lactone, 5-keto-d-gluconate, dl-lactate or methanol. For the assimilation of nitrogen compounds, growth on nitrate, nitrite, l-lysine, glucosamine and d-tryptophan is positive, whereas on ethylamine, cadaverine, creatine, creatinine or imidazole, it is negative. There is no growth in the presence of 5% glucose medium with 10% NaCl and 0.01% cycloheximide. Diazonium blue B test and urease activity are positive. The maximum growth temperature is 18 °C and optimal growth temperature is 15 °C.

Molecular characteristics (holotype).

nucleotide sequences of ITS and nuc 28S rDNA gene sequences are deposited in NCBI GenBank under the accession numbers are MK682818 and MK682815, respectively.

Deposits.

holotype, NYNU 18562 culture was isolated from the soil of the Lianhuashan National Forest Park, Jilin Province, China, in September 2018. The holotype culture is preserved in a metabolically inactive state at Microbiology Lab, Nanyang Normal University, Henan, China. Ex-type cultures are deposited at the China Centre of Industrial Culture Collection (CICC), Beijing, China, as CICC 33355, and at the CBS Yeast Collection of the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands, as CBS 15868.

Strains studied.

NYNU 18562; paratypes: NYNU 1941 and NYNU 18410 from two different soil samples in the Maoershan National Forest Park in Yanji city, Heilongjiang Province, China.

Figures

Figure 2. Morphology of Mrakia panshiensis (NYNU 18562 T) A budding cells B true hyphae with clamp connections and teliospores C teliospores in pairs D teliospores produced with a bud-like projection. Scale bars: 10 μm.