Please use this identifier to cite or link to this item:
|Title: ||Antibacterial activity of shrimp chitosan against Escherichia coli|
|Authors: ||Tsai Guo-Jane;Su Wen-Huey|
|Keywords: ||Antibacterial mechanism;shrimp chitosan;E. coli|
|Issue Date: ||2012-04-26T06:07:50Z
|Publisher: ||Journal of Food protection|
|Abstract: ||Abstract:The effects of cell age, reaction temperature, pH value and salts on the inhibitory activity of shrimp chitosan (98% deacetylation) in E. coli were investigated The age of a bacterial cell affected its susceptibility to chitosan, with cells in the late exponential phase being most sensitive to chitosan. Higher temperature (25oC and 37oC) and acidic pH increased the bactericidal effects of chitosan. The fact that sodium ions (100 mM Na+) reversed the bactericidal effect of chitosan at E. coli densities of 103-105 cfu/ml, but did not change chitosan activity at the lower cell density (102 cfu/ml), demonstrated that Na+ might complex with chitosan and accordingly reduced chitosan’s activity. Divalent cations at concentrations of 10 mM and 25 mM reduced the antibacterial activity of chitosan, in the order of Ba2+> Ca2+> Mg2+. Chitosan also causes leakage of glucose and lactate dehydrogenase from E. coli cells. These data support the hypothesis that the antibacterial mechanism of chitosan involves a crosslinkage between the polycations of chitosan and the anions on the bacterial surface, and that this crosslinkage changes the membrane permeability.|
|Relation: ||62(3), pp.239-243|
|Appears in Collections:||[食品科學系] 期刊論文|
Files in This Item:
There are no files associated with this item.
All items in NTOUR are protected by copyright, with all rights reserved.