identification of yeast species in traditional iranian fermented products

Fermented foods and beverages play an important role in maintaining human health. yeasts are one of the essential microbial groups for food fermentation and are found in fermented products. the current study aimed to investigate the diversity of yeast species from fermented foods and beverages in some regions of iran. samples were collected from traditional fermentation products including sourdough, kombucha, kefir, and water kefir. initially, 38 yeast isolates were studied morphologically and biochemically, followed by m13 dna fingerprinting. representatives identified through dna fingerprinting were selected for rdna-lsu (d1/d3 regions) sequencing. as a result, six species were identified. the identified yeast species belonged to ascomycetous yeasts, namely saccharomyces cerevisiae, pichia membranifaciens, p. kudriavzevii, p. fermentans, kazachstania servazzii, and kluyveromyces marxianus. sourdough samples showed more diversity of isolated yeast species compared to kombucha, water kefir and kefir samples.  saccharomyces cerevisiae was the only yeast species isolated from kombucha, kefir, and water kefir samples. the current research findings provide valuable insights into the yeast diversity of traditional fermented products.