Vegetos- An International Journal of Plant Research

  • Year: 2015
  • Volume: 28
  • Issue: 3

Isolation, Characterization and Identification of Lactic acid Bacteria from Lettuce and their Efficacy against Pathogenic Bacteria

École Supérieure des Industries Alimentaires de Tunis (ESIAT), UR « Sciences et Technologies des Aliments » (UR04AGR02, ESIAT), 58, Avenue Alain Savary, Cité El Khadra, CP: 1003, Tunis, Tunisie

1Cirad, UMR 95 Qualisud (B-95/1673, rue Jean-François Breton 34398, Montpellier, cedex 5)

Abstract

Biopreservation has recently been endorsed as an alternative to reduce microbial risks and conserve fresh products. This study focused on the importance of lactic acid bacteria (LAB) and its efficiency as a bioprotective agent. One hundred and fifty LAB strains were isolated from iceberg lettuce, characterized and identified using 16S rDNA sequencing and API 50CH. All strains displayed a considerable antibacterial activity against pathogenic bacteria namely Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium and Staphylococcus aureus. All the isolates were found to correspond to Lactobacillus plantarum strain. The results deduced that the production of organic acids was the most frequent mechanism of inhibition used among the tested isolates. Furthermore, it was proven that LAB strain harmed the growth of two foodborne pathogen bacteria, S. typhimurium and L. monocytogenes, in shredded iceberg lettuce.

Keywords

Lactobacillus plantarum; Lettuce; Salmonella typhimurium; Listeria monocytogenes; Biopreservation