No abstract

During a study on the biodiversity of yeasts and yeast-like ascomycetes from wild plants in Iran, four strains of yeast-like filamentous fungi were isolated from a healthy plant of Euphorbia polycaulis in the Qom Province, Iran (IR. of). All four strains formed small hyaline one-celled conidia from integrated conidiogenous cells directly on hyphae and sometimes on discrete phialides, as well as by microcyclic conidiation. Two strains additionally produced conidia in conidiomata that open by rupture. The internal transcribed spacer (ITS) sequences suggested the placement of these strains in the genera Collophorina (Leotiomycetes) and Coniochaeta (Sordariomycetes), respectively. Blast search results on NCBI GenBank and phylogenetic analyses of ITS, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the translation elongation factor 1α (EF-1α) sequences, and the nuclear large subunit ribosomal gene (LSU), partial actin (ACT), and β-tubulin (TUB) sequences, respectively , revealed the isolates to belong to three new species, that are described here as Collophorina euphorbiae, Coniochaeta iranica, and C. euphorbiae. All three species are characterised by morphological, physiological, and molecular data.

Significance and Impact of the Study: This study revealed the diversity of yeasts in some traditional kefir samples from Iran. Kluyveromyces marxianus was the dominant yeast species followed by Saccharomyces cerevisiae, P. fermentans and P. kudriavzevii. Three isolates of S. cerevisiae and one isolate of P. fermentans were exhibited high abilities of adherence to different solvents and auto-aggregation and acceptable adhesion to the epithelial intestine-derived cells but no antimicrobial activity against investigated pathogens. Although further studies on their health benefits and in vivo trials are required, these findings suggest that the yeast isolates can be considered as possible probiotic candidates for the development of novel functional foods.