Epsilonpolylysine

Epsilonpolylysine, often abbreviated as ε-PL, is a homopolymer of the amino acid lysine that is linked by peptide bonds at the epsilon-amino group of the lysine side chain. This unique linkage distinguishes it from the more common alpha-peptide bonds found in proteins. ε-PL is a positively charged molecule due to the presence of free alpha-amino groups and the terminal carboxyl group.

This biopolymer is produced naturally by certain species of Streptomyces bacteria, such as Streptomyces albulus. It has gained significant attention for its antimicrobial properties, particularly against Gram-positive bacteria and yeasts. The mechanism of action is thought to involve disruption of the bacterial cell membrane due to the positive charge of ε-PL interacting with the negatively charged components of the membrane.

Due to its natural origin and demonstrated safety, ε-PL has been approved for use as a food preservative in several countries, including Japan and China. It is effective at low concentrations and is considered an alternative to synthetic preservatives. Its applications extend beyond food to pharmaceuticals and cosmetics, where its antimicrobial and moisturizing properties are utilized. Research continues to explore its potential in various other fields, including drug delivery and wound healing.