Unveiling the Probiotic Properties of Lactic Acid Bacteria Inhabiting Tender Coconut Water

Abstract

This research delves into the unexplored potential of tender coconut water as a rich source of probiotics, with a focus on identifying promising probiotic lactic acid bacteria (LAB). By employing biochemical screening techniques, four potential LAB strains were isolated: Lactiplantibacillus plantarum CWJ3, Lacticaseibacillus paracasei CWKu14, Lacticaseibacillus rhamnosus CWKu12, and Lacticaseibacillus casei CWM15. These strains were comprehensively assessed to evaluate their resilience under various conditions: pH (2, 3, and 6.5), bile (0.3% and 0.5%), phenol (0.4% and 0.6%), salt (3% and 6%) concentrations, and temperatures (20°C, 37°C, 45°C, and 60°C). Further, resistance to lysozyme (100 mg L-1), artificial saliva juice (0.3% α-amylase, at pH 6.9), simulated gastric juice (0.3% pepsin, at pH 2), and simulated intestinal juice (0.3% Ox-gall and 0.1% pancreatin at pH 7) were determined. Their antibiotic susceptibility was tested against ten antibiotics at 100 ppm, and cell surface hydrophobicity, auto-aggregation, co-aggregation with selected pathogens, antibacterial activity, hemolytic activity, and DNase activity, also were evaluated. The statistical analysis demonstrated the survival of all four strains even in demanding circumstances, with Lactiplantibacillus plantarum CWJ3 displaying the greatest resilience. Optimum growth occurred at 37°C, while none of the strains survived at 60°C. A pH of 6.5 was optimal for their growth, and Lactiplantibacillus plantarum CWJ3 stood out as the only strain capable of withstanding pH 2 after 2 hours. Lacticaseibacillus rhamnosus CWKu12 and Lacticaseibacillus casei CWM15 showed the highest percentage of auto-aggregation and co-aggregation while Lacticaseibacillus rhamnosus CWKu12 and Lactiplantibacillus plantarum CWJ3 exhibited high cell surface hydrophobicity. The strains displayed susceptibility to Clarithromycin, Erythromycin, and Azithromycin, but resistance to Cefuroxime and Streptomycin antibiotics. All four strains inhibited various food-borne pathogens, showcasing their potential as probiotics. Moreover, they displayed no hemolytic or DNase activity. Remarkably, Lactiplantibacillus plantarum CWJ3 excelled in challenging environments, making it a noteworthy contender for a probiotic role.