Efficacy of multistrain blend of lactic acid bacteria (LAB) isolated from traditional dairy products and its comparison with individual strains

The current research was conducted for analyzing the efficacy of lactic acid bacteria (LAB) isolated from traditional dairy products collected from the local market of Prayagraj, India. The cultures were blended and evaluated for selective probiotic properties like viability in simulated gastric juice (SGJ) and simulated intestinal juice (SIJ), antimicrobial activity and antibiotic assay. The probiotic properties of individual strains were compared with the mixed strains. Molecular characterization was performed at NCCS, NCMR, Pune. The obtained isolates were Lactobacillus delbrueckii (curd), Lactobacillus fermentum (milk) and Lactiplantibacillus pentosus (buttermilk). Mixed strains had better viability upon exposure to SGJ with a reduction of only 6.32 log colony forming unit (cfu) whereas that of individual strains had 7.23, 7.27 and 7.15 log cfu for curd, raw milk and buttermilk, respectively. The log reduction of mixed strains in SIJ was only 1.82 log cfu, whereas that of individual strains was 1.99, 1.91 and 1.89 log cfu, respectively. Antimicrobial activity of mixed strain was found with enhanced zone of inhibition against common food pathogens like Escherichia coli, Staphyloccus aureus, Shigella flexneri and Salmonella enterica. Antibiotic assay performed with disk diffusion method clearly indicated that both the mixed and individual strains were susceptible to antibiotics except amphotericin (100 units). However, all the strains were susceptible towards other antibiotics like ampicillin, streptomycin, gentamycin, chloramphenicol, amoxicillin, penicillin, ciprofloxacin, etc. The research concluded that blending of (LAB) shows better response and it could be useful for development of futuristic probiotic supplements.

Automated summary

The current research analyzed the efficacy of lactic acid bacteria (LAB) isolated from traditional dairy products in Prayagraj, India. The mixed strains showed better viability and antimicrobial activity in simulated gastric juice and simulated intestinal juice compared to individual strains. Both the mixed and individual strains were susceptible to most antibiotics, except amphotericin.