Adhesion Abilities of the Isolated Lactic Acid Bacteria (LAB) from Tapai and the Effects of Prebiotic on It

Chen, Kai June (2016) Adhesion Abilities of the Isolated Lactic Acid Bacteria (LAB) from Tapai and the Effects of Prebiotic on It. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Lactic Acid Bacteria (LAB) have been well-known for their benefits to our human health. One of the most studied properties is their potential ability in reducing cholesterol. It has been found that Tapai, a fermented cooked white rice, glutinous rice or cassava, contains LAB which may be potential probiotics. The objectives of this study were to examine the aggregation activity, to measure the exopolysaccharides production (EPS) and to determine the effects of prebiotics on the isolated probiotics. The aggregation activity was conducted in two parts; autoaggregation (Only the LAB in the mixture) and coaggregation (one LAB and one pathogen in a mixture). Isolated LAB from tapai that have been characterized for its probiotic ability were used to test on the prebiotic effects by adding self-extracted xylo-oligosaccharides (XOS) and fructo-oligosaccharides (FOS) into the modified de Man, Rogosa and Sharpe (MRS) broth. Two strains of enterobactericeae were used which were Salmonella typhimurium (ATCC 14028) and Escherichia coli (ATCC 25922). As for the LAB, four strains were used, which are Lactobacillus sp., Lactobacillus plantarum 1, Lactobacillus plantarum 2, and Pediococcus pentosaceus. The results from auto-aggregation found that P. pentosaceus, L. plantarum 2 and Lactobacillus sp. have the highest autoaggregation percentage (84.56%±0.12, 82.76%±0.04 and 82.24%±0.15 respectively) after 24h incubation. In coaggregation, L. plantarum 2 has the highest coaggregation percentage with either of the pathogen after 24h incubation. In EPS production, L. plantarum 1 was found to produce the highest concentration of EPS, 390.2±3.5 mg/L. As for the prebiotic testing, all the LAB have a positive respond towards FOS but negative respond towards XOS. In conclusion, the probiotics have potential in adhering to the intestinal cell lining and inhibiting other enterobacteriaceae from adhering to the intestinal wall. Prebiotic FOS was found to enhance the function of the probiotics