Rhodotorula rosulata sp. nov., Rhodotorula silvestris sp. nov. and Rhodotorula straminea sp. nov., novel myo-inositol-assimilating yeast species in the Microbotryomycetes

Abstract

A distinguishing feature of the majority of the tremellomycetous yeasts is their ability to utilize a cyclitol, myoinositol, as sole source of carbon and energy. This characteristic, which, as a rule, is not shared by ascomycetous yeasts and by basidiomycetous yeasts of other classes, represents a fundamental key in yeast identification. Specifically, inositol assimilation is a criterion used to distinguish between anamorphic yeasts of the genera Cryptococcus Vuillemin and Rhodotorula Harrison (Kurtzman & Fell, 1998;Barnett et al., 2000). With a few exceptions, species of the genus Cryptococcus (subphylum Agaricomycotina) utilize both myo-inositol and D-glucuronate, the first intermediate of inositol catabolism, whereas species belonging to the genus Rhodotorula typically do not assimilate myo-inositol, and D-glucuronate assimilation is variable within this genus. Eukaryotes metabolize myoinositol via the D-glucuronate-L-gulonate pathway (Golubev, 1989), i.e. the sole step only, the oxidation of myo-inositol to D-glucuronate, is absent in D-glucuronatepositive but myo-inositol-negative Rhodotorula species. During a survey of yeasts from pine and spruce dead needle litters we found several isolates that were positive for both myo-inositol and D-glucuronate assimilation. A rDNA gene sequence analysis and a comparison of their phenotypic properties revealed that the isolates constitute novel anamorphic species in the Microbotryomycetes, for which the names Rhodotorula rosulata sp. nov., Rhodotorula silvestris sp. nov. and Rhodotorula straminea sp. nov. are proposed.The strains (isolation numbers: Pa-78, Pa-84, Pa-85, Ps-88, Ps-93, Ps-103, Ps-128 and Ps-130) were isolated from dead Abbreviation: ITS, internal transcribed spacer.The GenBank/EMBL/DDBJ accession numbers for the LSU rDNA gene D1/D2 domain sequences determined in this study are EU872490, GQ121044 and EU872489. Accession numbers for the ITS region sequences are EU872492, GQ121045 and EU872491.Phylogenetic trees based on sequence analysis of the D1/D2 domains of the LSU rDNA gene and the ITS regions are available with the online version of this paper.

Seasonal and altitudinal changes of culturable bacterial and yeast diversity in Alpine forest soils

“…They were also found to inhabit densely vegetated soils, including forest, podzolic and sod-podzolic soils, in regions with tropical, temperate and cold climates (Vishniac 2006; Fonseca et al 2011; Sugita 2011). Likewise, all yeast species found in this study, were also currently found as a part of yeast diversity in soil ecosystems (Golubev 1984; Maksimova and Cherov 2003; Wuczkowski and Prillinger 2004; Botha 2006; Golubtsova et al 2006; Lynch and Thorn 2006; Vishniac 2006; Golubev and Scorzetti 2010; Mestre et al 2011; Yurkov et al 2011, 2012, 2016; Buzzini et al 2012). As previously reported, soil yeasts can contribute to essential soil ecological processes, i.e.…”

Host species shape the community structure of culturable endophytes in fruits of wild berry species (Vaccinium myrtillus L., Empetrum nigrum L. and Vaccinium vitis-idaea L.)

“…Hannaella coprosmae , a basidiomycetous yeast, has been found on the phylloplane of plant leaves (Li et al . 2020 ), and Oberwinklerozyma straminea (or Rhodotorula straminea ) is a yeast found in dead needle litter of Picea abies L. and Pinus sylvestris L. (Golubev and Scorzetti 2010 ).…”

Screening of iron-enriched fungus from natural environment and evaluation of organically bound iron bioavailability in rats

“…The species belonging to the genus Rhodotorula typically do not assimilate myoinositol. It should be noted that such differentiation is becoming less distinct: there are more and more reports on inositol-positive Rhodotorula species (Golubev & Scorzetti, 2010).We found that the Rhodotorula No.BY1109 was positive for myoinositol assimilation. An rDNA gene sequence analysis and a comparison of its phenotypic properties revealed that the isolates might constitute novel anamorphic species in the Rhodotorula for which the names Rhodotorula langang sp are proposed.…”