Bacteriocins of lactic acid bacteria: extending the family

Abstract

Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are proteinaceous antimicrobial molecules with a diverse genetic origin, posttranslationally modified or not, that can help the producer organism to outcompete other bacterial species. In this review, we focus on the various types of bacteriocins that can be found in LAB and the organization and regulation of the gene clusters responsible for their production and biosynthesis, and consider the food applications of the prototype bacteriocins from LAB. Furthermore, we propose a revised classification of bacteriocins that can accommodate the increasing number of classes reported over the last years.

Keywords: Antimicrobial peptides; Bacteriocin; Circular bacteriocin; Glycocins; Lactic acid bacteria; Lantibiotics; Lasso peptides; Linear azole-containing peptides; Sactipeptides.

Fig. 1

Proposed classification scheme for bacteriocins and their structures. Classes identified in silico are depicted in gray. Structure of non-lytic bacteriocins of class III still remains uncharacterized. *Bacteriocins from non-lactic acid bacteria

Fig. 2

Schematic representation of bacteriocin gene clusters (not drawn to scale). Black, structural genes; dark gray, transporter genes; light gray, modification and maturation genes; bars, immunity genes; white, others. *Bacteriocins from non-lactic acid bacteria