Studies with bioengineered Nisin peptides highlight the broad-spectrum potency of Nisin V.
Bottom Line: In contrast, Nisin V displayed increased potency against all targets tested including hVISA strains and the hyper-virulent Clostridium difficile ribotype 027 and against important food pathogens such as Listeria monocytogenes and Bacillus cereus.Significantly, this enhanced activity was validated in a model food system against L. monocytogenes.We conclude that Nisin V possesses significant potential as a novel preservative or chemotherapeutic compound.
Affiliation: Department of Microbiology, University College Cork, Cork, Ireland.Show MeSH
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Mentions: To facilitate ongoing Nisin V‐ and T‐related research, we created producers, which are likely to be more genetically stable, through double cross‐over homologous recombination. This yields strains which are useful for peptide purification, but also is a strategy which is less likely to impinge on the food‐grade status of the producers as no heterologous DNA is present in the final constructs. The nisV and nisT genes (generated by PCR‐based mutagenesis) were each inserted at the appropriate location in the Lactococcus lactis NZ9800 chromosome via double cross‐over recombination to generate L. lactis NZ9800::nisV and L. lactis NZ9800::nisT. Lactococcus lactis NZ9800 is a derivative of NZ9700 that has a four‐base pair deletion in the nisA gene (Kuipers et al., 1993). Results of deferred antagonism assays with S. agalactiae ATCC 13813 and L. monocytogenes EGDe indicated that gene replacement had successfully occurred and that the bioactivity profiles of the newly constructed strains differed from that of L. lactis NZ9700 (Fig. 1A and B). Mass spectrometry analysis confirmed the production of peptides with masses corresponding to Nisin V (3321 amu) and Nisin T (3326 amu) (Fig. 1C). We also confirmed the absence of the pORI280 shuttle vector employed to facilitate the recombination process (data not shown). It was noted that these newly created Nisin V and T producers produced levels of peptide that corresponded closely with those produced when the corresponding structural genes were expressed on a multicopy vector (data not shown).
Affiliation: Department of Microbiology, University College Cork, Cork, Ireland.