Class II antimicrobial peptides from lactic acid bacteria

Strains of lactic acid bacteria (LAB) produce a wide variety of antibacteri al peptides. More than fifty of these so-called peptide bacteriocins have b een isolated in the last few years. They contain 20-60 amino acids, and are cationic and hydrophobic in nature. Several of these bacteriocins consist of two complementary peptides. The peptide bacteriocins of LAB are inhibito ry at concentrations in the nanomolar range, and cause membrane permeabiliz ation and leakage of intracellular components in sensitive cells. The inhib itory spectrum is limited to gram-positive bacteria,and in many cases to ba cteria closely related to the producing strain. Among the target organisms ar food spoilage bacteria and pathogens such as Listeria, so that many of t hese antimicrobial peptides could have a potential as food preservatives as well as in medical applications. (C) 2000 John Wiley & Sons, Inc.