Characterization of Lactic Acid Bacteria Isolated from Coconut Wine (Mnazi) for Probiotic Potential

Abstract

Lactic acid bacteria (LAB) are useful in human health as probiotics. To achieve this they need to reach the gastro-intestinal tract and remain viable. A total of fifteen strains of lactic acid bacteria isolated from fermented coconut wine (Mnazi) were screened in vitro for their safety and probiotic properties,acid tolerance, bile tolerance, survival under conditions of simulated gastrointestinal tract (GIT) passage and their antimicrobial activity against indicator organisms using standard techniques. Further they were assessed for production and properties of bacteriocins produced and characterized using sequencing and phylogenetic analysis. The results revealed that the fifteen isolateswere safe to use, able to tolerate and grow well in conditions of reduced pH (2 and 2.5) and extremes of bile (up to 2%) that simulate stomach duodenal passage environment. They are also potent against both Gram positive and negative bacteria which they inhibit through production of bacteriocins. Most had β-galactosidase activity which makes them suited for moderation of lactose intolerance. Further, they were able to utilize frustooligosaccharides making them beneficial in regulating the microbiota in the colon. The isolates are phylogenetically distant from other homologous Lactobacillusspp though they were similar to L. paracasei, L. casei, L. rhamnosus and L. zeae. These findings show that the LAB isolates from Mnazi had desirable probiotic properties and were safe to use.This provides an opportunity for further investigation of the isolates for utilisation as starter cultures in fermentation of different food products to increase their value to human or animal health.