Purification and characterization of a novel bacteriocin from Lactobacillus paracasei ZFM54

Bacteriocins from lactic acid bacteria (LAB) arouse general concern in recent years due to their antimicrobial activities against foodborne pathogenic microorganisms. In this study, a novel bacteriocin named as bacteriocin ZFM54, produced by Lactobacillus paracasei ZFM54 isolated from the feces of newborn infant, was purified by a four-step strategy including macroporous resin XAD-16 adsorption chromatography, cation exchange chromatography, Sephadex G-25 gel filtration chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). The molecular weight of bacteriocin ZFM54 was 1143.39 Da, the predicted amino acid sequence was ATTLIPPVFGK. Bacteriocin ZFM54 was highly thermostable, active under the acidic condition, sensitive to trypsin and proteinase K, while insensitive to a-amylase, lysozyme, lipase, and ribonuclease A. The bacteriocin possessed a broad-spectrum inhibition against many foodborne pathogens such as Salmonella typhimurium, Micrococcus luteus and Listeria monocytogenes. The mode of action of bacteriocin ZFM54 was related to the pore formation of cell membrane. We further demonstrated that Lipid II, the molecular target of the prototype lantibiotic Nisin, was not the specific target of this bacteriocin. Together, this new bacteriocin has great potential to be used as a biological preservative in the food industry.

Automated summary

A novel bacteriocin named ZFM54, produced by Lactobacillus paracasei ZFM54, was isolated from newborn infant feces, possessing high thermal stability and broad-spectrum antimicrobial activity, making it a potential biological preservative in the food industry.