Probiotic potential of lactic acid bacteria isolated from Ethiopian traditional fermented Cheka beverage

Abstract

: Lactic acid bacteria (LAB) are a cluster of microbes distributed in a variety of environments and have potential probiotic activity to improve human well-being. This study was aimed at assessing the probiotic potential of LAB isolated from Cheka, an Ethiopian traditionally fermented beverage. Pure isolates obtained from 16 Cheka samples from Konso (n = 8) and Derashe (n = 8) were characterized morphologically, biochemically, and physiologically by considering basic criteria to identify the LAB. The probiotics properties of the LAB were evaluated in vitro at low pH values (2.0 and 3.0), and two bile salt concentrations (0.3 and 0.5%) for 3 and 6 h. The 16 S rRNA gene sequencing was done using an ABI 3730xl sequencer, and the gene sequences were aligned. Of the 27 pure isolates, 11 isolates were proven to be LAB with non-motile, negative for catalase, and non-spore former characteristics. Based on cultural characteristics and sugar fermentation ability, the 11 isolates were assembled into the genera Lactobacillus (55%), Lactococcus (18%), Pediococcus (18%), and Leuconostoc (9%). At pH 3.0 and a bile salt concentration of 0.3%, isolate ChK-11 showed a better survival rate (97 and 94%) than other isolates [ChK-7 (93 and 80%) > ChD-5 (84 and 76%) > ChD-8 (46 and 36%) > ChK-4 (41 and 34%)] for 6 and 3 h, respectively. According to 16 S rRNA sequencing results, isolates ChK-11 and ChK-7 were found to be Weissella paramesenteroides and Leuconostoc pseudomesenteroides with sequence similarity of 99 and 91%, respectively. In the present study, probiotic LAB (Weissella paramesenteroides and Leuconostoc pseudomesenteroides) was successfully isolated and sequenced from Cheka samples. The findings of this in vitro study indicated that fermented beverages like Cheka are a source of the LAB with probiotic functional properties. Overall, Weissella paramesenteroides and Leuconostoc pseudomesenteroides isolates, which showed promising probiotic properties under in vitro conditions, can be used for starter culture development for the Cheka fermentation process.