Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Food Microbiology
Vol. 38, 2014, Pages: 192–200

Inhibition of Escherichia coli O157:H7 and Salmonella entericaon spinach and identification of antimicrobial substances produced by a commercial Lactic Acid Bacteria food safety intervention

Thelma F. Cálix-Lara, Mahitha Rajendran , Stephen T. Talcott , Stephen B. Smith ,Rhonda K. Miller , Alejandro Castillo , Joseph M. Sturino , T. Matthew Taylor

Department of Animal Science, Texas A&M University, College Station, TX 77843-2471, United States.

Abstract

The microbiological safety of fresh produce is of concern for the U.S. food supply. Members of the Lactic Acid Bacteria (LAB) have been reported to antagonize pathogens by competing for nutrients and by secretion of substances with antimicrobial activity, including organic acids, peroxides, and antimicrobial polypeptides. The objectives of this research were to: (i) determine the capacity of a commercial LAB food antimicrobial to inhibit  Escherichia coli O157:H7 and Salmonella enterica on spinach leaf surfaces, and (ii) identify antimicrobial substances produced in vitro by the LAB comprising the food antimicrobial. Pathogens were inoculated on freshly harvested spinach, followed by application of the LAB antimicrobial. Treated spinach was aerobically incubated up to 12 days at 7°C and surviving pathogens enumerated via selective/differential plating. l-Lactic acid and a bacteriocin-like inhibitory substance (BLIS) were detected and quantified from cell-free fermentates obtained from LAB-inoculated liquid microbiological medium. Application of 8.0 log10 CFU/g LAB produced significant (p < 0.05) reductions in E. coli O157:H7 andSalmonella populations on spinach of 1.6 and 1.9 log10 CFU/g, respectively. It was concluded the LAB antimicrobial inhibited foodborne pathogens on spinach during refrigerated storage, likely the result of the production of metabolites with antimicrobial activity.

Keywords: SalmonellaEscherichia coli O157:H7; Spinach; Lactic Acid Bacteria; Biopreservation; Antimicrobials.


 
 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution