Panorama of poly-ε-lysine

Abstract

Poly-ε-lysine (ε-PL), (S)-poly(imino(2-amino-1-oxo-1,6-hexanediyl)), is a naturally occurring homopolymer of L-lysine with a degree of polymerization of 25–35, and characterized by peptide bonds between the carboxyl and ε-amino groups of L-lysine. ε-PL is currently receiving much attention due to its wide applications in chemical, pharmaceutical, food, medical, clinical chemistry, biotechnology and other industries. Moreover, it is water-soluble, biodegradable, heat stable, edible and nontoxic towards humans. The present review discusses the production, recovery, characterization, biodegradation and applications of ε-PL. Production of ε-PL by fermentation is detailed, along with its industrial problems such as biodegradation. Various purification techniques for higher recovery of ε-PL are also described here. Issues of ε-PL degrading enzyme and its characterization studies have also been addressed. Molecular genetics as a tool for development of highly productive strains is also discussed herein. Applications of ε-PL in various industries showed to have an increasing impact on bioprocessing.