Potential of Lactic Acid Bacteria Isolated from Fermented Foods for Yogurt Production and Antimicrobial Activity

Objective:The main objective is to determine potential of Lactic acid bacteria isolated from fermented foods for yogurt production and antimicrobial activity.Methods: A total of 20 samples of 4 different types of fermented foods (Gundruk, Sinki, Pickles and Cheese) were collected from different district and research was carried out in microbiological laboratory of D.A.V. College.Lactic acid bacteria (LAB) were isolated from fermented foods and identified through gram staining, catalase, motility, O/F, carbohydrate fermentation and salt concentrations test.Yogurt was prepared using isolated LAB.Probiotic property of isolated LAB was determined by observing growth on 3.1 pH 1.0 N HCl MRS broth and 0.3% sodium taurocholate.Bacteriocin was extracted by centrifugation technique and antimicrobial activity of bacteriocin was performed by agar well diffusion assay.Result: Among 20 different samples, LAB was isolated from Sinki (S2 and S3) and Gundruk (S5) sample only i.e., 15% of total sample.And identified as Lactobacillus genera.Isolated LAB showed growth on 3.1 pH 1.0 N HCl MRS broth and 0.3% sodium taurocholate i.e., has probiotic potential.Extracted bacteriocin showed inhibitory action against Bacillus spp.and Escherichia coli.Yogurt was prepared using isolated LAB and on comparing it with yogurt prepared by using standard thermophilic Freeze-dried lactic culture, the physiochemical properties of yogurt like pH, titratable acidity and syneresis were within suitable standard range during 14 days of storage (4ºC). Conclusion:The overall, result indicated that LAB can be isolated from traditional fermented foods and isolated LAB have potential as commercial starter culture for yogurt production.The bacteriocin extracted showed inhibitory action against different bacteria.As a result, bacteriocin like molecules can potentially increase shelf life by inhibiting growth of spoilage causing microbes.