Enhancement of antibacterial compound production in lactic acid bacteria by co-cultivation

Abstract

The rising threat of antibiotic resistance necessitates the development of alternative antimicrobial strategies. Lactic Acid Bacteria (LAB), are GRAS or generally recognized as safe, produce antibacterial compounds with potential applications in food safety and preservation. This study aimed to optimize the production of antibacterial compounds by LAB isolates from goat’s milk through co-cultivation. Three LAB isolates were co-cultivated under varying pH levels (5.5, 6.0, and 6.5) and incubation temperatures (25°C, 30°C, and 37°C). Their antimicrobial activity was evaluated against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus using the Kirby-Bauer disc diffusion method. Co-cultivation significantly enhanced antimicrobial activity compared to individual LAB isolates, producing inhibition zones of up to 22.76 mm against B. subtilis and 17.5 mm against S. aureus. In contrast, weaker inhibition was observed against E. coli and P. aeruginosa, with zones below 12 mm. Co-cultivation of LAB isolates from goat’s milk enhances the yield and efficacy of antibacterial compounds, offering a promising approach for mitigating antibiotic-resistant pathogens and improving food safety applications.