Characterization of Bacteriocins Produced by Lactic Acid Bacteria of Industrial Interest

Abstract

Bacteriocins have long been studied because of their huge potential as natural foodpreservatives that could be the perfect replacement of the extensively used but dangerouschemical preservatives. Application approaches of bacteriocin uses as biopreservatives infoods include the addition of the purified bacteriocin, which may be expensive and theircommercialization as food additives requires regulatory approval. On the other hand, abacteriocinogenic strain can be added to food so the bacteriocin will be produced in situ.Our results show that Leuc. citreum MB1 is effective in delaying List. monocytogenesgrowth in milk during refrigerated storage. Moreover, the highest production ofbacteriocin was observed when Leuc. citreum MB1 was cultured at 25 °C and at pHvalues between 5 and 6, which are suboptimal conditions for bacterial growth. In turn,the incubation of diverse LAB with the bacteriocin-containing supernatant did not affecttheir normal growth, excepting for very closely related strains belonging to Leuc.mesenteroides and Leuc. pseudomesenteroides species. Direct incorporation of abacteriocin-producer strain during the manufacture of fermented foods presents manyadvantages, since the metabolites produced during its development can contribute to theflavor and act as biopreservative agents as well. Furthermore, this is a more economicaloption in comparison to the use of purified bacteriocin and is subject to less regulatorycontrols.