Recovery of chitin and chitosan from shrimp waste by chemical and microbial methods
Chitin is a versatile environmentally friendly modern material (Mahmoud, 2007). It is a naturally occurring high molecular weight linear homopolysaccharide composed of N-acetyl-D glucosamine residues in α(1-4) linkage. Chitin and chitin derivatives are biodegradable and biocompatible natural polymers that have been used in virtually every significant segment of the economy (e.g. water treatment, pulp and paper industry, biomedical devices and therapies, cosmetics, biotechnology, agriculture, food science and membrane technology) (Li et al., 1997). Chitin can be found in a variety of species in both the animal and plant kingdoms. The traditional source of chitin is shellfish waste from shrimp, Antarctic Krill, crab and lobster processing (Muzzarelli, 1977; Shahidi, 1991). It is present in amounts varying from trace quantities up to about 40% of the body weight of the organism. The crustacean waste is the most important chitin source for commercial use due to its high chitin content and ready availability (Gagné and Simpson, 1993; Subasinghe, 1995). However, chitin present in the crustacean waste is associated with proteins, minerals (mainly calcium carbonate) and lipids including pigments.