The Diversity of Bacteriocins in Gram-Positive Bacteria

Abstract

Gram-positive bacteria, and especially the lactic acid bacteria (LAB), are now increasingly studied for their production of bacteriocin-like inhibitory activity. This has yielded detailed insight into many unique features of this surprisingly heterogeneous array of antibiotic molecules, a group apparently united only by their proteinaceous composition and targeted killing of bacte- ria generally closely related to the producer bacterium. Contemporary devel- opments in this field have included increased knowledge of factors influencing bacteriocin expression, mode of action and specific host-cell immunity. Much of the burgeoning interest in the bacteriocin-producing LAB is driven by their perceived potential practical applications either to food preservation or as probiotics. In this chapter, we propose that all of the currently confirmed bacteriocins of Gram-positive bacteria can be classified into four broad groups: (1) lantibiotics, (2) small non-modified peptides, (3) large proteins, and (4) cyclic peptides.