Record Details

Low Molecular Weight Chitosan-Preparation with the Aid of Pepsin, Characterization, and its Bactericidal Activity

IR@CSIR-CFTRI

View Archive Info
 
 
Field Value
 
Relation http://ir.cftri.com/1607/
Bio-01-07
 
Title Low Molecular Weight Chitosan-Preparation with the Aid of Pepsin, Characterization, and its Bactericidal Activity
 
Creator Vishu Kumar, Acharya B
Varadaraj, M. C.
Tharanathan, R. N.
 
Subject 13 Molecular Biochemistry
11 Food Biochemistry
 
Description Pepsin (EC 3.4.4.1) from porcine stomach mucosa caused depolymerization of a chitosan sample (a copolymer of glucosamine and N-acetylglucosamine linked by -1-4-glycosidic bonds). N-terminal sequence and zymogram analyses confirmed dual (proteolytic and chitosanolytic) activities of pepsin. Optimum depolymerization occurred at pH 5.0 and 45 C with an activity of 4.98 U. Low molecular weight chitosan (LMWC), the major depolymerization product, was obtained in a yield of 75-82%, the degree of polymerization of which depended on reaction time. The LMWC showed a nearly 10-14-fold decrease in the molecular mass as compared to native chitosan, which was also confirmed by GPC and HPLC analyses. IR and 13C NMR spectra indicated a decrease in the degree of acetylation (DA, ~13.4-18.8%) as compared to native chitosan (~25.7%), which was in accordance with the CD analysis. Native chitosan had a crystallinity index (CrI) of ~70%, whereas there was a decrease in the CrI of LMWC (~61%). The latter showed a better bactericidal activity toward both Bacillus cereus and Escherichia coli, which was more toward the former. The bactericidal activity was essentially due to the lytic and not static effect of LMWC, as evidenced by the pore formation on the bacterial cell surface when observed under SEM. This study suggests the possible use of pepsin in place of chitosanase, which is expensive and unavailable in bulk quantities for the production of LMWC of desired molecular mass that has diversified applications in various fields.
 
Date 2007
 
Type Article
PeerReviewed
 
Identifier Vishu Kumar, Acharya B and Varadaraj, M. C. and Tharanathan, R. N. (2007) Low Molecular Weight Chitosan-Preparation with the Aid of Pepsin, Characterization, and its Bactericidal Activity. Biomacromolecules, 8 (2). pp. 566-572.