A gene cluster encoding plantaricin 1.25 beta and other bacteriocin-like peptides in Lactobacillus plantarum TMW1.25

Plantaricin 1.25 beta is a thermostable class two bacteriocin produced by L actobacillus plantarum TMW1.25 isolated from sausage fermentation. It is co -produced with several other bacteriocin-like peptides. Using oligonucleoti des derived from previously determined peptide sequences, a 3.8 kb DNA frag ment could be amplified. A neighboring 1.8 kb fragment was amplified using ligation-anchored single-specific-primer PCR. Sequencing of the complete 5. 6 kb stretch revealed that the structural gene for plantaricin 1.25 beta, p lnB, was located downstream of another bacteriocin gene, plnC. Seven other open reading frames were detected, including plnK encoding a bacteriocin-li ke peptide, but not including any putative immunity genes. Interestingly, t he gene cluster contained an IS30-like insertion sequence, designated IS125 , as well as an ISS1 homolog. (C) 2000 Elsevier Science B.V. All rights res erved.