title: Production and characterization of nisin-like peptide produced by a strain of Lactococcus lactis isolated from fermented milk.
abstract: An isolate of Lactococcus lactis from fermented milk was found to produce a bacteriocin peptide. The isolate could grow in a medium with an initial pH of 11.0, in which it produced the bacteriocin extracellularly at the highest level. The level of the bacteriocin in the medium increased in parallel to the bacterial growth and reached its peak during the late exponential phase; thereafter it plateaued. The bacteriocin had a broad antibacterial spectrum similar to that of nisin and inhibited several related species of lactic acid bacteria and other gram-positive bacteria. The inhibitory activity of the bacteriocin was found to be stable over a wide range of pH and temperature. The molecular weight of the peptide was judged to be 2.5 kDa by SDS-polyacrylamide gel electrophoresis.
authors.affiliation: Department of Botany, Visva-Bharati, Santiniketan, West Bengal, 731235, India.
authors.forename: Suranjita
authors.initials: S
authors.lastname: Mitra
authors.forename: Pran Krishna
authors.initials: PK
authors.lastname: Chakrabartty
authors.forename: Swadesh Ranjan
authors.initials: SR
authors.lastname: Biswas
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology*; D001430:Bacteriocins / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology; D043302:Cultured Milk Products / Q000382:microbiology*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013294:Lactococcus lactis / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009561:Nisin / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D009561:Nisin