Wickerhamiella nakhonpathomensis f.a. sp. nov., a novel ascomycetous yeast species isolated from a mushroom and a flower in Thailand

Abstract

Strains SU22T (TBRC 14875T) and FLA11.5, representing a novel anamorphic yeast species, were respectively isolated from a fruiting body of a Coprinus species and an inflorescence of a Coffea species collected in Thailand. Analysis of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) regions showed that the two strains differed by two nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and were identical in the ITS regions. Wickerhamiella drosophilae CBS 8459T was the most closely related species, but with 24–26 nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 24 nucleotide substitutions in the ITS regions. A phylogenetic analysis, based on the sequences of the D1/D2 domains, indicated that the two strains represented a species in the genus Wickerhamiella which was distinct from other recognized species of the genus. Therefore, the two strains were assigned as a novel species, for which we propose the name Wickerhamiella nakhonpathomensis f.a. sp. nov. The holotype is TBRC 14875T (isotype PYCC 8914T). The MycoBank number of the novel species is MB 840833.

Three new yeast species from flowers of Camellia sinensis var. assamica collected in Northern Thailand and their tannin tolerance characterization

“…Approximately 1 g of the tea flower sample was homogenized in 10 mL of sterile 0.85% NaCl as a diluent using a Masticator ® homogenizer blender (Barcelona, Spain) for 5 min. After that, the homogenate was serially diluted to 10 0 –10 5 with the diluent, and 0.1 mL of each dilution was plated on yeast–malt extract agar (YMA) (1% yeast extract, 2% peptone, 2% glucose, and 1.5% agar) supplemented with 100 mg/L of chloramphenicol and then incubated at 30°C for 48 h. Yeast colonies with distinct morphologies were isolated and streaked on the same medium without the supplementation of chloramphenicol for purification ( Khunnamwong et al, 2022 ). For storage, a single colony of each yeast isolate was inoculated in yeast–malt extract broth (YMB) (1% yeast extract, 2% peptone, and 2% glucose) and incubated at 30°C on a 150-rpm rotary shaker for 24 h. The culture was mixed with 30% (v/v) glycerol to make a final concentration of 15% before being stored at −80°C.…”

Wickerhamiella bidentis sp. nov., a novel yeast species isolated from flowers and insects in Japan

“…Two phylogenetic trees based on the sequence of D1/D2 domain derived from ML and NJ analyses showed that the two strains, NBRC 115686 T and NBRC 115687, formed a subclade with W. galacta in the Wickerhamiella clade but in a distinct position from the other Wickerhamiella species in this subclade, with high bootstrap support ( and S1, available in the online version of this article). NBRC 115686 T varies from previously known species of the clade by roughly 12 % in the D1/D2 domains, indicating a significant degree of sequence divergence sufficient to differentiate them at the species level [4, 5, 7, 15–17]. These results suggest the presence of multiple unknown species yet to be discovered.…”

“…The Wickerhamiella species is highly specialized nutritionally [8]. Commonly, Wickerhamiella species are able to assimilate d -glucose and l -sorbose but not inulin, raffinose, melibiose, lactose, trehalose, maltose, melezitose, soluble starch, cellobiose, d -salicin, l -rhamnose, l -arabinose, d -ribose, methanol, erythritol, galactitol, myo -inositol, citrate or N -acetyl- d -glucosamine [5]. In this study, the novel species we isolated can be distinguished from the most closely related Wickerhamiella species through phenotypic characteristics.…”

“…Recently, members of the Wickerhamiella species have been isolated from various habitats as follows: flowers (W. kurtzmanii) [16]; insects (W. dianesei) [16]; distillery effluent (W. shivajii) [4]; mushroom (W. nakhonpathomensis) [5]; cattle and grease traps (W. martinezcruziae, W. osmotolerans and W. tropicalis) [15,17]; and human sources (W. verensis) [7]. Although the ecology of Wickerhamiella in the wild is unknown, most members of the clade are considered to be highly specialized ecologically with a restricted physiology [8].…”

“…Wickerhamiella is a genus of ascomycetous yeast that was established in 1973, and the cells of species of the clade are one of the smallest known for yeasts [1]. At the time of writing, the Wickerhamiella clade consists of 45 species that include seven species with a known sexual state (producing ascospores): Wickerhamiella australiensis, Wickerhamiella cacticola, Wickerhamiella domercqiae, Wickerhamiella lipophila, Wickerhamiella occidentalis, Wickerhamiella pagnoccae and Wickerhamiella shivajii [2][3][4][5]. Most species do not ferment glucose or produce filamentous growth [6].…”