Screening for bacteriocin-producing lactic acid bacteria from various moroccan food products and partial characterization of putative bacteriocins

Abstract

Screening for anti-Listeria bacteriocin-producing (Bac+) lactic acid bacteria was carried out from different food products and the spectrum of action was determined against different Gram-positive and Gramnegative food borne bacteria of health and spoilage significance as well as closely related lactic acid bacteria. A total of 2242 strains randomly isolated from different foods were screened for the production of bacteriocin active againstL. monocytogenes. The results showed that Bac+ strains were more frequently isolated from dairy products (∼95% of the positive isolates and 7.5% of overall dairy isolates) and that strains belonging to Enterococcus, Lactococcus and Streptococcus genera were the most represented with 76, 17.6 and 2.8% of the positive isolates, respectively. Conversely, Lactobacilli were not isolated from any of the tested dairy samples. While all strains were inhibitory to L. monocytogenes used as an indicator during the screening step, some of them were inhibitory to other pathogenic or spoilage Gram-negative or Gram-positive bacteria by the well diffusion assay. © 2007 Asian Network for Scientific Information.