Targeting bacteriocin genes in lactic acid bacteria: what we need to know

Abstract

In the last decade, the aim of several research papers has focused on the determination of bacteriocin genes in genomic or plasmid DNA of lactic acid bacteria (LAB). These reports can be divided in two major groups; the first of which contains articles reporting the detection of these genes and giving a scientific proof of their expression, usually through RT-PCR, or by the amino-acid sequencing of the produced bacteriocin. In the second group, the presence of known bacteriocin genes in genomic or plasmid DNA of newly isolated LAB is reported, but authors do not provide any significant evidence that the detected genes are or might be expressed. These latter reports need to be received with high criticism and skepticism. Combination of the bio-molecular and bio-chemical approaches is critical in the better understanding of the expression of genes encoding the bacteriocins from LAB.In this review we summarize these two groups of research: those targeting the bacteriocin genes with a solid proof of expression of the bacteriocins and those that only report on the presence of the bacteriocins genes in the genomic and plasmid DNA.