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International Journal of Polymer Science
Volume 2014, Article ID 162173, 8 pages
Research Article

Production of High Viscosity Chitosan from Biologically Purified Chitin Isolated by Microbial Fermentation and Deproteinization

Department of Microbiology, Faculty of Science, King Mongkut’s University of Technology Thonburi, Pracha Uthit Road, Bangkok 10140, Thailand

Received 17 September 2013; Revised 16 December 2013; Accepted 8 March 2014; Published 23 April 2014

Academic Editor: Christopher Batich

Copyright © 2014 Ekkalak Ploydee and Saipin Chaiyanan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The objective of this study was to produce high viscosity chitosan from shrimp chitin prepared by using a two-step biological treatment process: decalcification and deproteinization. Glucose was fermented with Lactobacillus pentosus L7 to lactic acid. At a pH of , the calcium carbonate of the shells was solubilized in 48 hours. The amounts of residual calcium in the form of ash ( ) and crude protein ( ) were further eliminated by the activity of proteolytic Bacillus thuringiensis SA. After decalcification and deproteinization of the shrimp shells, residual calcium and crude protein of shrimp chitin flakes were % and , respectively. Chitin was deacetylated with 50% NaOH at 121°C for 5 hours. After deacetylation, the chitosan had residual calcium, crude protein content, and degree of acetylation of , , and , respectively. The viscosity of chitosan prepared from chitin extracted by this two-step biological process was , whereas chitosan prepared from chemically processed chitin had a viscosity of , indicating that biologically purified chitin gave chitosan with a high quality.