Nisin: Difference between revisions

<StructureSection load='1wco' size='340' side='right' caption='60/607847/Nisin_structure/4 in complex with lipid (PDB code [[1wco]])' scene=''>

'''Nisin''' is a polycylic antibacterial peptide, with 34 amino acid residues used as a food preservative.  

While in general most bacteriocins inhibit only closely related species, nisin is a rare example of a "broad-spectrum" bacteriocin effective against many Gram-positive organisms, including lactic acid bacteria (commonly associated with spoilage), ''Listeria monocytogenes'' (a known pathogen), ''Staphylococcus aureus,'' ''Bacillus cereus'', ''Clostridium botulinum'', etc. It is also particularly effective against spores. Gram-negative bacteria are protected by their outer membrane but may become susceptible to nisin action after a heat shock or when this is coupled with the chelator EDTA. Nisin is soluble in water and can be effective at levels nearing the parts-per-billion range<ref>PMID:184764</ref>.

In the food industry, it is obtained from the culturing of ''L. lactis'' on natural substrates, such as milk or dextrose, and is not chemically synthesized.  Nisin is studied as a novel antibiotic due to its antimicrobial activity and as a therapeutic against neck and head squamous cell carcinoma<ref>PMID:3544465</ref>.