Research progress on production methods of ε-poly-l-lysine

Abstract

ε-poly-l-lysine (ε-PL) is a safe and environmentally friendly natural biological preservative, by 25~35 lysine residues through the intermolecular carboxyl group and amino amino condensation to form an amide bond to form l-lysine homopolymer, with high antibacterial activity, degradation in the human body must l-lysine, used in food and cosmetics and other industries. It is widely used in the United States, Japan and China. At present, the production cost of ε-PL is too high, and it is mainly produced by the fermentation of Streptomyces, but the Streptomyces is a non-GRAS(Generally Recognized As Safe) strain, not a general food-grade strain certified by the US Food and Drug Administration. In this review, the current biotechnological fermentation methods of Streptomyces albicans to produce ε-PL and the research progress of heterogenic expression of ε-PL through genetic engineering were reviewed. Increasing the output of ε-PL is of great significance for breaking the technological blockade and improving the core competitiveness of our country. The purpose of this review is to use genetic engineering technology to combine fermentation production, improve the yield of ε-PL from the genetic level, construct food-grade production strains, and further expand the method of ε-PL production.