In many food-production fields, LAB-produced bacteriocins (antimicrobial peptides) are exploited for their ability to biologically preserve food through elimination of other microorganisms (Cintas et al., 2001; Cotter et al., 2005). Bacteriocins are a diverse collection of peptides and small proteins that have a wide range of activity against LAB and other Gram-positive bacteria (Cintas et al., 2001; Klaenhammer, 1993). In the brewing industry, bacteriocins may eliminate other LAB or non-LAB beer spoilage organisms either through direct action against the cell or indirectly by contributing to the acidification of wort, making it less hospitable for bacterial growth (Lewis, 1998; Vaughan et al., 2005; Rouse and van Sinderen, 2008). The most studied bacteriocin in the context of brewing is nisin (Delves-Broughton et al., 1996; Vaughan et al., 2005); however, chitosan (Gil et al., 2004) and the bacteriocinogenic activity of the barley isolate Lactococcus lactic M30 have also been evaluated for use (Basanta et al., 2007).
Bacteriocins are an attractive means for controlling BSR LAB growth, as they could be used in place of potentially harmful sanitizers or acid-washing which may affect yeast viability (Delves-Broughton et al., 1996; Ogden et al., 1988; Vaughan et al., 2005). Further, bacteriocins theoretically could be added at most stages of the brewing production process in order to target either specific contaminated sites or introduce an inherent method of control (Delves-Broughton et al., 1996; Ogden et al., 1988; Vaughan et al., 2004, 2005). Interest in bacteriocins has increased to the point that there is potential to develop and use yeast starter cultures genetically modified to produce bacteriocins or develop wort bioacidifying LAB (Dequin, 2001; James et al., 2013; Van Reenen et al., 2003). This approach would potentially allow for the selection or development of LAB starter cultures suitable for use in craft-fermentations, such that the LAB involved eventually limit their own growth by the production of, or exposure to, bacteriocins.