Chapter 15 - Preparation, properties, and application of low-molecular-weight chitosan

Abstract

Chitosan, a linear polyamine copolymer of β-(1-4)-d-glucosamine and acetyl-β-(1-4)-d-glucosamine, has been considered to be an excellent biomaterial possessing diverse bioactivities, such as nontoxicity, biocompatibility, biodegradation, antioxidant, antibacterial agents and so on. Moreover, by having many reactive primary amino groups, chitosan can be chemical modified to a large number of beneficial derivatives for various applications. However, the physicochemical and biological properties of chitosan are known to depend very much on its molecular weight. Practically, low-molecular-weight chitosan (LMWC) has been shown to possess high biological activities, which enable it to be used as plant defense elicitors, growth stimulators, feed additives, antimicrobial agents, etc. This chapter will provide the different preparation methods of LMWC, including physical, chemical, and biological methods. The various properties of prepared LMWC are also discussed. In addition, the potential applications of LMWC for agriculture, aquaculture, food technology, water treatment, and among others are presented.