Lactococcus lactis producing ent35-mccv inhibits growth of foodborne pathogens in situ

ACUÑA L; CORBALAN NS; QUINTELA-BALUJA M; BARROS-VELAZQUEZ J; BELLOMIO A

Rosario

Congreso; Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

SAIB

Bacteriocins are being used as 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 a transcriptional fusion between the sequence enconding the signal peptide of enterocin P (a bacteriocin secreted by SEC system) and Ent35-MccV (a broad spectrum chimerical bacteriocin). The hybrid gene SPentP-munA-cvaC was fused by PCR downstream to the constitutive P32 promoter. The genetic construction was cloned into a shuttle Escherichia coli-Lactococcus vector named pAK80 obtaining the pRUK. L. lactis NZ9000 (pRUK) was tested for the bacteriocin production and secretion by antimicrobial activity and colony MALDI-TOF. Moreover, in-situ inhibition of L. lactis NZ9000 (pRUK) on Listeria monocytogenes and E. coli food isolates mixed cultures in skim milk were assayed. 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.