Detection and partial characterization of a broad-range bacteriocin produced by Lactobacillus plantarum (ATCC 8014)

Lactobacillus plantarum (ATCC 8014) was tested for production of antimicrobial compounds. This study demonstrates that the cell-free supernatant of L. plantarum is effective in inhibiting the growth of a wide range of Gram-positive and Gram-negative bacteria including, Staphylococcus aureus, Escherichia coli, Listeria innocua, and Pseudomonas aeruginosa. The inhibitory compound lost activity when heated to temperatures greater than 30 degreesC and when subjected to pH changes that lowered the pH below 4 or above 5. In addition, the inhibitory protein was susceptible to digestion by various proteases. The apparent molecular weight based on SDS-PAGE analysis is 122 KDa. These findings support the idea that the inhibitory compound is a protein and can be considered a bacteriocin secreted from the Gram-positive bacterium L. plantarum. (C) 2004 Elsevier Ltd. All rights reserved.