Plantaricin MG active against Gram-negative bacteria produced by Lactobacillus plantarum KLDS1.0391 isolated from “Jiaoke”, a traditional fermented cream from China

A bacteriocin named plantaricin MG produced by Lactobacillus plantarum KLDS1.0391 which was isolated from “Jiaoke”, a traditional, naturally fermented cream from Inner Mongolia in China is reported in this article. Plantaricin MG was purified by ammonium sulfate precipitation followed by sequential gel filtration chromatography and reverse-phase chromatography. Mass spectrometry analysis showed the mass of plantaricin MG to be approximately 2180 Da. The bacteriocin showed a broad inhibitory activity against Gram-positive and Gram-negative bacteria including Listeria monocytogenes, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli. The bacteriocin was extremely heat-stable (30 min at 121 °C) and remained active after incubation at pH 2.0–10.0. It was found to be sensitive to proteolytic enzymes (pepsin, trypsin, papain, α-chymotrypsin, proteinase K, Neutrase and Alcalase). The mode of action of plantaricin MG was identified as bactericidal.