Antimicrobial activity chitosan preparation

A number of important papers could not be cited in this chapter, due to the length limitations and the specific target of the chapter. For example, the antimicrobial activity of chitosans [349], the chitinolytic enzymes, the preparation of cosmetics, and the occurrence of chitin in fungi [350] are some of the subjects not dealt with specifically here, notwithstanding their importance. 

Rhim, J.-W., Hong, S.-I., Park, H.-W., and Ng, P. K. W. (2006). Preparation and characterization of chitosan-based nanocomposite films with antimicrobial activity. J. Agric. Food Chem. 54,5814-5822. 

Tsai et al. (2002) studied the effects of DD and preparation methods for chitin and chitosan on their antimicrobial activity. It was found that chemically (ch-chitin) and microbiologically prepared chitin (MO-chitin) could undergo further chemical deacetylation to produce chitosan with different DDs. However, MO-chitin that was deacetylated by various proteases had no antimicrobial activity (Tsai et al., 2002). However, for chitosan, as the DD increased, its antimicrobial effect on bacteria increased, even to a greater extent than that on fungi. 

The most common biopolymers derived from animals are chitin and chito-san. Chitin is a macromolecule found in the shells of crabs, lobsters, shrimps, and insects. The primary unit in the chitin polymer is 2-deoxy-2-(acetylamino) glucose. Chitin can be degraded by chitinase. Chitosan is a modified natural carbohydrate polymer derived from deactylation of chitin, which occurs principally in animals of the phylum Arthropoda. Chitosan is also prepared from squid pens. Chitin is insoluble in its native form but chitosan, the partly deacetylated form, is water soluble. The materials are biocompatible and have antimicrobial activities as well as the ability to absorb heavy metal ions [16]. 

Chen, S., Zeng, H., Wu, G., 2005. Preparation of high antimicrobial activity thiourea chitosan-Ag+ complex. Carbohydrate Polymers 60, 33—38. 

Clay/PLA nanocomposites were prepared by casting method. The tested clays were montmorillonite and two organomodified clays with two quaternary ammonium salts which had exhibited antimicrobial characteristics in chitosan films. In general, the films presented improved physical properties but only films containing Cloisite 30B presented some antimicrobial activity against L. monocytogenes. No effect was observed in other... 

Chanthateyanonth, R., Ruchirawat, S., and Srisit-thiratkul, C. (2010). Preparation of New Water-Soluble Chitosan Containing Hyperbranched-Vinylsulfonic Acid Sodium Salt and Their Antimicrobial Activities and Chelation with Metals. J. Appl. Polym. Sci. 116, 2074-2082. 

Li L-H, Deng J-C, Deng H-R, Liu Z-L, Li X-L (2010) Preparation, characterization and antimicrobial activities of chitosan/Ag/ZnO blend films. Chem Eng J 160 378-382 Lin M-F, Thakur VK, Tan EJ, Lee PS (2011a) Dopant induced hollow BaTi03 nanostructures for application in high performance capacitors. J Mater Chem 21 16500-16504 Lin M-F, Thakur VK, Tan EJ, Lee PS (2011b) Surface functionalization of BaTiOj nanoparticles and improved electrical properties of BaTiOa/polyvinylidene fluoride composite. RSC Adv 1 576-578... 

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