Characterization of lactic acid bacteria isolated from budu, a West Sumatra fish fermentation product, and their ability to produce exopolysaccharides

Abstract

Background: Probiotics are instrumental in maintaining the equilibrium of the gut microbiota and improving the health of the human body. This study examined the presence and physiological features, including the ability to produce exopolysaccharides, of lactic acid bacteria from fermented Tenggiri (Scomberomorus guttatus) and Talang (Chorinemus spp.) fish, also known as budu fish. Methods: Lactic acid bacteria were isolated from budu fish. These bacteria were characterized to determine tolerance to gastric pH values, growth curve, inhibitory ability against pathogenic bacteria, and ability to produce exopolysaccharides and to perform a molecular identification. Results: Twenty-nine lactic acid bacteria isolates from budu fish were determined to be of the Pediococcus species. Assessment of the physiological characteristics showed that Pediococcus sp. had a high acidifying activity and could grow at a pH between 2 and 11; the pH of the supernatant after 36 hours of incubation was 4.49. In terms of inhibitory activity against pathogenic bacteria, Pediococcus sp. demonstrated an inhibitory diameter of 20.5 mm against Escherichia coli, 23.0 mm against Staphylococcus aureus, and 21.0 mm against Salmonella thypi. The Pediococcus sp. strain produced exopolysaccharides ranging from 870 to 1910 mg/l and had 100% similarity with Pediococcus pentosaceus strain 4942. Conclusions: This study confirmed the presence of Pediococcus pentosaceus strain 4942 in budu fish, which can be used as a new probiotic based on its capabilities to kill pathogenic bacteria and produce exopolysaccharide compounds.