Aim: To develop an inducible gene expression system for Lactobacillus sakei, based on the regulatory system of sakacin A production.
Methods and Results: A Lactobacillus/Escherichia coli shuttle vector; pKRV3, was constructed including the signal transducing system genes of the bacteriocin sakacin A. The gusA gene fused to PsapA promoter, cloned in this vector allowed for inducible β-glucuronidase expression in L. sakei and L. plantarum following the addition of the sakacin A inducing peptide. PsapA appeared to be a strong and tightly controlled promoter when compared with known promoters.
Conclusion: The pKRV3 system can be used as an inducible gene expression system in lactobacilli.
Significance and Impact of the Study: A novel, inducible gene expression system has been developed for lactic acid bacteria relevant in food fermentations.