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; SAIB L Reunión Anual; 2014

SAIB

Bacteriocins are being used as food biopreservative agents. The main drawback is that they have a restricted spectrumof action against related bacteria to those that produce the bacteriocin. In order to obtain a broad spectrumbacteriocin-producing lactic acid bacterium, we carried out a transcriptional fusion between the sequence encondingthe signal peptide of enterocin P (a bacteriocin secreted by SEC system) and Ent35-MccV (a broad spectrumchimerical bacteriocin). The hybrid gene SPentP-munA-cvaC was fused by PCR downstream to the constitutive P32promoter. The genetic construction was cloned into a shuttle Escherichia coli-Lactococcus vector named pAK80obtaining the pRUK. L. lactis NZ9000 (pRUK) was tested for the bacteriocin production and secretion byantimicrobial activity and colony MALDI-TOF. Moreover, in-situ inhibition of L. lactis NZ9000 (pRUK) on Listeriamonocytogenes and E. coli food isolates mixed cultures in skim milk were assayed. The results showed that L. lactisNZ900 (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 tocontrol Gram (-) and Gram (+) foodborne pathogens in food products.