Studies On Degradation And Antibacterial Activity Of CM-Chitosan

CM-Chitosan is a amphiprotic polyelectrolyte, it contains amino-group and carboxylic, so it has many characteristics. Methods of degradation and antibacterial effect of the derivatives, interrelated factors of degradation and antibacterial effect were studied in this paper.1. The degradation of CM-ChitosanA series of CM-Chitosan with different molecular weights were prepared by taking advantage of H2O2oxidizer. The degradating factors such as temperature, degradating time, the concentration of H2O2, the conditions of sedimentation and making powder were researched. The results showed:degradating conditions of3000CM-Chitosan were: temperature60℃,10mL oxidizer every time, reaction time3.2h; degradating conditions of6000CM-Chitosan were:temperature60℃,5mL oxidizer every time, reaction time1h; degradating conditions of9000CM-Chitosan were:temperature50℃,5mL oxidizer every time, reaction time0.6h.The sedimentation conditions were:the volumn ratio of95%ethanol to degradation liquid3:1, sedimentation40min-50min, washing it twice with95%ethanol. After filtered, the resulting matter was dried at50℃,40min.2. Antibacterial effect of CM-ChitosanThe antibacterial effect of CM-Chitosan of different molecular weights to some kinds of bacteria was studied. The interrelated factors such as molecular weights, concentration, pH of CM-Chitosan were studied. The results showed:the MIC (CM-Chitosan of3000kd) to Escherichia coli, Staphylococcus aureus, Aspergillus niger, Microzyme were0.10%,0.15%,0.15%,0.15%, respectively; the MIC (CM-Chitosan of6000kd) to Escherichia coli, Staphylococcus aureus, Aspergillus niger, Microzyme0.15%,0.15%,0.20%,0.15%, respectively; the MIC (CM-Chitosan of9000kd) to Escherichia coli, Staphylococcus aureus, Aspergillus niger, Microzyme0.20%,0.10%,0.20%,0.20%, respectively. CM-Chitosan had optimal inhibiton to the4bacteria at pH6.5.3. Application of CM-Chitosan The hygroscopicity and moisture retention were studied in this paper. The results showed:CM-Chitosan of3000molecular weight was the best in hygroscopicity and moisture retention.The effect of CM-Chitosan in vegetable juice was tested. The results showed:the sums of colony and coliforrm group were20/mL,2/mL,respectively. Antibacterial effect was in accordance with the national standards.