Characterization halotolerant lactic acid bacteria Pediococcus pentosaceus HN10 and in vivo evaluation for bacterial pathogens inhibition

This study reports the isolation of a potential probiotic lactic acid bacteria (LAB) from fermented Solanum macrocarpon food and evaluates shrimp bacterial pathogens' inhibition. The isolate was determined by identifying the inhibition zone against Vibrio parahaemolyticus with an antagonistic activity of 360 AU/mL. Molecular identification based on 16S rRNA indicated that the isolate belongs to the Pediococcus genus, named as Pediococcus pentosaceus HN10. The isolate exhibited effective inhibitory ability against various pathogenic including antibiotic-resistant Vibrio spp., Escherichia coli ATCC 85922 and Staphylococcus aureus ATCC 25023. P. pentosaceus HN10 showed potential probiotic properties such as strong salt tolerance, low pH and bile salts resistance, autoaggregation and coaggregation activities. P. pentosaceus HN10 was negative for β-hemolytic and amino acid decarboxylase. Antibiotic resistance assay showed that this strain was sensitive to ampicillin and chloramphenicol. P. pentosaceus HN10 expressed strongly antioxidant activity. In vivo challenge to V. parahaemolyticus in shrimp model indicated P. pentosaceus HN10 enhanced survival rate, weight gain as well as reduced the number of Vibrio in shrimp intestine tract. Overall, this study suggests that P. pentosaceus HN10 could be applied as a supplementation feed for shrimp to minimize pathogenic bacteria's negative effect.