Nisin: Difference between revisions
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<StructureSection load=' | <StructureSection load='1wco' size='340' side='right' caption='60/607847/Nisin_structure/4' scene=''> | ||
<ref>PMID:21638687</ref> | |||
== Function == | |||
[[nisin]] is a polycylic | [[nisin]] is a polycylic antibacterial peptide, with 34 amino acid residues used as a food preservative. | ||
Nisin is produced by fermentation using the bacterium Lactococcus lactis | Nisin is produced by fermentation using the bacterium ''Lactococcus lactis''. | ||
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. | 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. | ||
== Disease == | == Disease == | ||
== Relevance == | == Relevance == | ||
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. | |||
== Structural highlights == | == Structural highlights == | ||
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<scene name='60/607847/Spacefill/1'>Here</scene> you can see the peptid in a spacefill presentation. | <scene name='60/607847/Spacefill/1'>Here</scene> you can see the peptid in a spacefill presentation. | ||
</StructureSection> | </StructureSection> | ||
== 3D structure of nisin == | |||
[[1wco]] - Nisin + lipid - ''Lactococcus lactis'' - NMR<br /> | |||
== References == | == References == | ||
<references/> | <references/> | ||