A SYSTEM FOR HETEROLOGOUS EXPRESSION OF BACTERIOCINS IN LACTOBACILLUS-SAKE

A system for efficient heterologous expression of class II bacteriocin s is described that is based on introducing two plasmids in a bacterio cin-negative Lactobacillus sake strain. The first plasmid (pSAK20) con tains the genes necessary for transcriptional activation of the Sakaci n A promoter as well as export and processing of bacteriocin precursor s. The second plasmid (a pLPV111 derivative) contains the structural a nd immunity genes for the bacteriocin of interest fused to the sakacin A promoter. Using this system, various bacteriocins were produced at levels equal to or higher than those obtained with the corresponding w ild-type producer strains. (C) 1998 Published by Elsevier Science B.V. All rights reserved.