ε-poly-L-lysine or ε-polylysine is a new food biopreservative compared with natamycin and nisin. This ingredient is a natural antimicrobial peptide metabolized by Streptomyces and has a wide antibacterial spectrum against Gram-negative, Gram-positive bacteria, yeasts, and molds. Commonly used in the preservation of rice, soups, noodles and sliced fish (sushi).

http://www.chinafooding.com/L-Lysine