Coproduction of colicin V and lactic acid bacteria bacteriocins in lactococci and enterococci strains of biotechnological interest.

Abstract

The aim of this study was the coproduction in a single strain of the Gram-negative bacteriocin colicin V with other bacteriocins from lactic acid bacteria (LAB). Colicin V was expressed in Lactococcus and Enterococcus strains by replacing the colicin V leader peptide by the leader peptide and promoter of d-alanyl-d-alanine carboxypeptidase from Lactobacillus reuteri CECT925 in pNZ8048 (pNZ:LR-colV). The antimicrobial activity of colicin V against the indicator organism Escherichia coli DH5α in transformed strains was checked by agar diffusion assay and SDS-PAGE analysis. Lactococcus and Enterococcus transformed with pNZ:LR-colV were able to coproduce colicin V at high levels together with other LAB bacteriocins such as nisin A, nisin Z, lacticin 481 or enterocins A and B, obtaining broad-spectrum activity strains with large potential applications. The construction showed in this work could be used for the heterologous expression of other bacteriocins active against Gram-negative bacteria or wide-spectrum bacteriocins from LAB.