Production of Fungal Chitosan by Enzymatic Method and Applications in Plant Tissue Culture and Tissue Engineering: 11 Years of Our Progress, Present Situation and Future Prospects

Abstract

Introduction Chitin is a copolymer of N-acetyl-D-glucosamine and D-glucosamine units linked with β-(1- 4)-glycosidic bond, here N-acetyl-D-glucosamine units are predominant in that polymer chain. The deacetylated form of chitin refers to chitosan. Chitin usually refers to a copolymer with a degree of acetylation (DA) of more than 40% [i.e., number of N-acetyl-D- glucosamine more than 40% and number of D-glucosamine less than 60%] and insoluble in dilute acids. The name chitosan is used for a copolymer with less than 40% DA [i.e., more than 60% DD (degree of deacetylation), number of N-acetyl-D-glucosamine less than 40% and number of D-glucosamine more than 60%] that, in most cases, will be soluble in dilute acid (Nwe & Stevens, 2008). Chitin and chitosan are found as supporting materials in many aquatic organisms (shells of shrimps and crabs and bone plates of squids and cuttlefishes), in many insects (mosquitoes, cockroaches, honey bees, silkworms, Drosophila melanogaster, Extatosoma tiaratum and Sipyloidea sipylus), in terrestrial crustaceans (Armadillidium vulgare, Porcellio scaber), in nematode, in mushrooms (Agaricus bisporus, Auricularia auriculajudae, Lentinula edodes, Trametes versicolor, Armillaria mellea, Pleurotus ostreatus, Pleurotus sajo-caju and Pleurotus eryngii) and in some of microorganisms (yeast, fungus, and algae) (Carlberg, 1982; Nemtsev et al., 2004; Veronico et al., 2001; Paulino et al., 2006; Moussian et al., 2005; Tauber, 2005; Hild et al., 2008; Anantaraman & Ravindranath, 1976; Pochanavanich & Suntornsuk, 2002; Mario et al., 2008; Yen & Mau, 2007 cited in Nwe et al., 2010).