Review: Bacteriocins of Lactic Acid Bacteria

Abstract

During the last few years, a large number of new bacteriocins produced by lactic acid bacteria (LAB) have been identified and characterized. LAB-bacteriocins comprise a heterogeneous group of physicochemically diverse ribosomally-synthesized peptides or proteins showing a narrow or broad antimicrobial activity spectrum against Gram-positive bacteria. Bacteriocins are classified into separate groups such as the lantibiotics (Class I); the small (<10 kDa) heat-stable postranslationally unmodified non-lantibiotics (Class II), further subdivided in the pediocin-like and anti Listeria bacteriocins (subclass IIa), the two-peptide bacteriocins (subclass IIb), and the sec-dependent bacteriocins (subclass IIc); and the large (>30 kDa) heat-labile non-lantibiotics (Class III). Most bacteriocins characterized to date belong to Class II and are synthesized as precursor peptides (preprobacteriocins) containing an N-terminal double-glycine leader peptide, which is cleaved off concomitantly with externalization of biologically active bacteriocins by a dedicated ABC-transporter and its accessory protein. However, the recently identified sec-dependent bacteriocins contain an N-terminal signal peptide that directs bacteriocin secretion through the general secretory pathway (GSP). Most LAB-bacteriocins act on sensitive cells by destabilization and permeabilization of the cytoplasmic membrane through the formation of transitory poration complexes or ionic channels that cause the reduction or dissipation of the proton motive force (PMF). Bacteriocin producing LAB strains protect themselves against the toxicity of their own bacteriocins by the expression of a specific immunity protein which is generally encoded in the bacteriocin operon. Bacteriocin production in LAB is frequently regulated by a three-component signal transduction system consisting of an induction factor (IF), and histidine protein kinase (HPK) and a response regulator (RR). This paper presents an updated review on the general knowledge about physicochemical properties, molecular mode of action, biosynthesis, regulation and genetics of LAB-bacteriocins.

Investigation on the potential application of biological agents in the extension of shelf life of fresh beef in Nigeria

“…Millette et al (2008) have reported similar detection of the bacteriocin in Pediococcus strains. The use of bacteriocin producing LAB as biopreservatives may have major applications in improving safety in food products including meat (Cintas et al 2001).…”

“…The researchers concluded that the LAB used as protective cultures could have generated some antimicrobials that were effective for the control of coliforms. However, the ability of the pediocin-producing P. pentosaceus LIV01 to control coliforms in this study may not be due to its ability to produce bacteriocin, but rather to production of other antimicrobial agents such organic acids, diacetyl or hydrogen peroxide (Cintas et al 2001). This is because bacteriocins act against species that are only closely related to the producer organism (Klaenhammer 1988;Cleveland et al 2001).…”

“…An increase of about 3 log was recorded in the uninoculated control samples from day 0 to day 7 of storage. Susceptibility of the foodborne pathogen to class IIa bacteriocin, such as pediocin, has been reported (Cintas et al 2001;Djenane et al 2005). The organism, L. monocytogenes, is a known threat to food safety (Colak et al 2007) and it can contaminate meat and products during slaughter, processing and production.…”

Biochemical and Microbiological Changes during the Ivorian Sorghum Beer Deterioration at Different Storage Temperatures

“…Despite these detrimental metabolic activities, some LAB may play a positive role in the brewing process by eliminating undesirable microorganisms such as beer-spoilage LAB and by contributing to wort bioacidification [32,34]. LAB may account for food biological preservation mainly by the production of ribosomally-synthesized antimicrobial peptides, referred to as bacteriocins [35][36][37].…”

Intraguild predation provides a selection mechanism for bacterial antagonistic compounds

“…Some, but far from all, LAB bacteriocin operons are located on chromosomes [24,25,44,118], which may reduce fitness cost as argued by Dykes & Hastings [29], assuming that no other selective forces are relevant. Another way to reduce the fitness cost of bacteriocin production is to assess whether the bacteriocin has moonlighting properties [119], meaning that it serves cellular functions other than interbacterial warfare.…”