In-vitro Antagonist Effect of Bacteriocins Isolated from Fermented Vegetables against Pathogenic Microorganisms

Abstract

Fermented foods are known as probiotics which contain healthy live bacteria. These foods undergone fermentation process during which bacteria converts the starches and sugars in that food into lactic acid and acetic acid. These foods have high nutritional values, easy to prepare and are economical. The bacteriocins produced by lactic acid bacteria (LAB) acts as antimicrobial substances or preservative component on fermented food product. Fermented vegetables and fruits can be utilized as potential probiotics as many lactic acid bacteria are grown in them. The present study was aimed to isolate bacteriocins from fermented carrots, cabbage and beetroot vegetables and to determine their antagonist effect. The lactobacilli were isolated by inoculating in MRS broth media and were identified by Gram’s staining, motility and biochemical tests and also antibacterial efficacy by agar well diffusion method. The sterile nutrient agar media was inoculated with Staphylococcus aureus (MTCC 11949), Bacillus subtilis (MTCC 10010), Escherichia coli (MTCC 9721) and Pseudomonas aeruginosa (MTCC 9800). The wells were punched in inoculated media and 104, 106 cells/ml of lactobacilli were filled. The plates were incubated at 370C for 24 hrs in upright position. The Lactic acid bacteria isolated from fermented carrot, cabbage & beet root exhibited good anti-bacterial activity against tested pathogenic bacteria. The Lactic acid bacteria inhibited highly gram-ve bacteria than gram +ve bacteria. Fermented vegetable products are microbiologically safe, nutritious, and flavourful; have appealing sensory characteristics; and can be conveniently stored for extended periods without refrigeration. Numerous studies on probiotics have linked their use to improved intestinal balance and function, lowered serum cholesterol, boosted immunity, and a lower risk of colon cancer, among other health benefits.