Gokila Thangavel* and Subramaniyan Thiruvengadam Pages 401 - 409 ( 9 )
Background: World Health Organization has estimated that 1 in 10 people fall ill and 4, 20, 000 die every year from eating contaminated food. Food pathogens like Escherichia, Salmonella, Staphylococcus and Listeria pose a serious threat to human health.
Objective: The objective was to isolate microbes from meat stored at refrigerated conditions and evaluate the antimicrobial activity of the cell-free supernatant against food pathogens.
Methods: Chicken and Pork samples were procured and stored at refrigerated conditions (4-7ºC) for 2 weeks. The samples were plated on to Nutrient agar (NA) and De Man, Rogosa and Sharpe (MRS) agar for isolation of aerobic and lactic acid bacteria. Cell-free supernatants of the isolates were screened for antimicrobial activity against Escherichia coli, Salmonella typhimurium, Listeria monocytogenes and Staphylococcus aureus by microtiter plate assay. The 5 most - effective strains were screened for hemolytic activity and identified by 16s rRNA sequencing.
Results: A total of 110 strains were isolated, out of which the top 5 most - effective strains were all from MRS agar. They showed 88-90% inhibition against E. coli and S. typhimurium, whereas 60 to 70 % against S. aureus and L. monocytogenes. These strains were found to be non - hemolytic and were identified as Leuconostoc spp. namely, L. mesenteroides subsp. mesenteroides J18, CP003101; L. mesenteroides LM2; L. mesenteroides ATCC 8293, CP000414; L. gelidum subsp. gasicomitatum LM G 18811 and L. mesenteroides; LM2, AY675249.
Conclusion: Leuconostoc are known to be effective in controlling foodborne pathogens and therefore, these strains have the potential for application in food and human.
Food pathogens, antimicrobial activity, Leuconostoc, Hemolytic activity, 16s rRNA sequencing, E. coli, Salmonella.
Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Department of Biotechnology, Rajalakshmi Engineering College, Chennai