Submitted to: Federation Of European Microbiological Societies Yeast Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 2001
Publication Date: N/A
Interpretive Summary: A vast number of microorganisms are found in foods and beverages. Some are necessary for the manufacture of these products, whereas others may cause disease or spoilage. Despite all the work done in microbiology, many of the species found in foods and beverages are new to science. In the present study, a new yeast (Zygosaccharomyces kombuchaensis) was discovered in the popular fermented beverage call Kombucha tea. This species was not recognized from the standard growth tests employed in many laboratories but from it unique gene sequences (genetic material). Based on its growth characteristics, this species does not appear to be a health risk, but because it is closely related to yeasts that commonly spoil high sugar acidic foods, it may represent a previously unrecognized food spoilage microorganism. This work is part of National Program 108 Food Safety.
Technical Abstract: A new ascosporogenous yeast, Zygosaccharomyces kombuchaensis sp. n. (type strain NRRL YB-4811, CBS 8849), is described and was isolated from Kombucha tea, a popular fermented tea-based beverage. The four known strains of the new species have identical nucleotide sequences in domain D1/D2 of 26S rDNA. Phylogenetic analysis of D1/D2 and 18S rDNA sequences places Z. kombuchaensis near Z. lentus. The two species are indistinguishable on standard physiological tests used for yeast identification but can be recognized from differences in RFLP patterns obtained by digestion of 18S-ITS1 amplicons with the restriction enzymes Dde I and Mbo I.