Isolation, molecular and phylogenetic identification of microorganisms from Kombucha solution and evaluation of their viability using flow cytometery

Abstract

Kombucha can be produced by coculture of a consortium of bacteria and fungi in a sweetened black tea. Determining the type of microbial population as well as their survival is important because they lead to beneficial and sensory properties of the product. In this study, microorganisms were isolated from kombucha and identified using culture and molecular methods and vacuum dried. Also total phenol content, and antioxidant properties of beverage were characterized. Microorganism viability and sensory evaluation was conducted by flow cytometery and a 5-point hedonic test before and after drying. 8-isolated species were recorded in NCBI. Lactobacillus and Kumagataeibacter and Weissella spp. were the bacterial species, while Starmella bacillaris and Hanseniaspora uvarum were the 2-yeast species identified in kombucha beverage. Microbial count increased from 3.59% on the start day to 96.6% on day 14. The results of sensory evaluation show that, in general, the produced kombucha drink was accepted by the evaluators. The highest score for overall acceptance on day 14 was equal to 4.6. Starmella bacillaris and Hanseniaspora uvarum were first isolated from kombucha with enhanced antioxidant properties. These strains, together with yeast are recommended for use in beverage fermentation processes to production of bioactive compounds.

Keywords:
Kombucha beverage; antioxidant capacity; viability; flow cytometery