Purification and characterization of plantaricin LR14: a novel bacteriocin produced by Lactobacillus plantarum LR/14.
Bacteriocin produced by Lactobacillus plantarum strain LR/14 was purified to homogeneity by a multi-step protocol consisting of ammonium sulfate precipitation, cation-exchange chromatography, gel-filtration, and reverse-phase FPLC. L. plantarum LR/14 secreted a low-molecular-weight bacteriocin consisting of two peptides designated as plantaricin LR14alpha and -beta with molecular mass of 3,012.46 and 5,605.74 Da, respectively. The purified peptides were characterized to be highly thermostable and active in acidic pH range, with a pI of >10.0. Both alpha and beta peptides showed bactericidal mode of action against indicator strain, Micrococcus luteus and together showed a synergistic action. These peptides were differentially sensitive to a range of proteolytic enzymes, indicating differences in their composition. Amino acid sequencing revealed that the N-terminus in both the cases is blocked; thus, only a partial sequence could be obtained after CNBr digestion. These sequences, when compared with those available in the database, showed no homology with known bacteriocins, indicating it to be a novel compound.
Tiwari
Santosh Kumar
SK
Department of Genetics, University of Delhi South Campus, New Delhi, India.
Srivastava
Sheela
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D001430:Bacteriocins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D007526:Isoelectric Point; D048191:Lactiplantibacillus plantarum / Q000737:chemistry* / Q000378:metabolism; D016982:Micrococcus luteus / Q000187:drug effects; D008969:Molecular Sequence Data; D008970:Molecular Weight
D001426:Bacterial Proteins; D001430:Bacteriocins