ε - Polylysine is a light yellow powder with strong hygroscopicity and a slight bitterness. It is a linear polymer of lysine, which is produced by fermentation by Streptomyces and has a broad-spectrum antibacterial effect. ε - polylysine is polymerized from 25-30 lysine groups in Chemicalbook, and is relatively stable to pH and heat. Its antibacterial effect is related to the degree of polymerization and environment. The best antibacterial activity is found between 3600-4300 molecular weights.