Characterization of a two-peptide plantaricin produced by Lactobacillus plantarum MBSa4 isolated from Brazilian salami

The aim of this study was to explore the biochemical and genetic features of the two-peptide bacteriocin produced by a Lactobacillus plantarum strain isolated from Italian type salami produced in Brazil (Lb. plantarum MBSa4). Identification of bacteriocinogenic Lb. plantarum MBSa4 was performed by 16S rRNA sequencing. Expressed bacteriocin was evaluated for spectrum of activity, heat and pH stability, mechanism of action, and molecular mass. Partial purification was achieved by cation-exchange, and reversed phase - HPLC. Total DNA of Lb. plantarum MBSa4 was extracted and tested for presence of previously described bacteriocin genes. Bacteriocin MBSa4 was heat-stable, unaffected by pH 2.0 to 6.0 and active against all tested Listeria monocytogenes strains and most of tested fungi. Maximal production (1600 AU/ml) in MRS broth occurred after 22 h at 25 degrees C, presenting bacteriostatic activity as result of combined action of two components. The molecular mass determined by SDS-PAGE was 23 kDa. PCR-amplified DNA indicated the same nucleotide sequence of plantaricin W. Results indicate that Lb. plantarum MBSa4 produces plantaricin W, a two-peptide lantibiotic with remarkable anti-Listeria activity. (c) 2015 Elsevier Ltd. All rights reserved.