CHAPTER 2: Antimicrobial Activity of Chitosan in Food, Agriculture and Biomedicine

Increasing attention has been shown in recent years on natural antimicrobial compounds. In particular, chitosan (a natural biodegradable, biocompatible and nontoxic biopolysaccharide derived from chitin) is one to the most abundant and promising biopolymers. Its unique chemical structure, involving high positive charge density as well as reactive amino and hydroxyl groups, provides chitosan a great potential for a wide range of applications. Chitosan and its derivatives exhibit high antimicrobial activity against a wide variety of pathogenic and spoilage micro-organisms including Gram-positive and Gram-negative bacteria, fungi, and viruses. The antimicrobial action is affected by various intrinsic and extrinsic factors and the understanding of their influence on the activity as well as the mechanisms of action has become a key issue for its better and more efficient use as antimicrobial systems in many fields of applications.