Lactococcus lactis producing the broad spectrum bacteriocin Ent35-MccV inhibits growth of food borne pathogens in-situ

ACUÑA, L; CORBALAN , N.; QUINTELA-BALUJA M.; BARROS-VELÁZQUEZ, J.; BELLOMIO, A.

Rosario, Argentina.

Congreso; L Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Bacteriocins are being used as new food biopreservative agents. The main drawback is that they have a restricted spectrum of action against related bacteria to those that produce the bacteriocin. In order to obtain a broad spectrum bacteriocin-producing lactic acid bacterium, we carried out by asymmetric PCR a transcriptional fusion between the signal peptide of enterocin P (a bacteriocin produced by SEC system) and Ent35-MccV (a broad spectrum chimerical bacteriocin). The hybrid gene SPentP-munA-cvaC was fused by PCR downstream to P32 promoter. The obtained fusion P32-SPentP-munA-cvaC was and cloned into the vector pAK80 obtaining the plasmid called pRUK. The strain Lactococcus lactis NZ9000 was transformed with pRUK and tested the bacteriocin production by antimicrobial activity, colony MALDI-TOF and viability assays of L. lactis NZ9000 (pRUK)/Listeria monocytogenes or Escherichia coli food isolates mixed cultures in skim milk. The results showed that L. lactis NZ900 (pRUK) was able to produce Ent35-MccV and could inhibit the growth of both, the Gram (+) L. monocytogenes and the Gram (-) E. coli in skim milk. As far as we know, the results of this study indicate that Ent35-MccV is the first example of a lineal genetically-engineered bacteriocin produced in-situ as an effective approach to control Gram (-) and Gram (+) foodborne pathogens in food products.