不同分子量壳聚糖的制备及其抑菌性能的研究

本实验在超声波条件下用过氧化氢降解壳聚糖制备低分子量壳聚糖,研究了过氧化氢用量、温度、时间、pH值等对壳聚糖溶液粘均分子量的影响,并对降解产物进行红外光谱分析。探讨了降解产物对大肠杆菌、白色念珠菌、枯草芽孢杆菌的抑菌性能。实验结果表明,超声波协同过氧化氢氧化降解壳聚糖的较适宜条件为:1%(w/v)的壳聚糖溶液,加入3%(v/v)的过氧化氢溶液,pH值约为5.0,数控超声清洗仪工作功率为80%,频率为40kHz,温度设定为(50.0±2.0)℃,随着降解时间不同可得到不同粘均分子量的壳聚糖。降解得到的产物对三种细菌均有抑制生长的效果,其中粘均分子量为5.0×104的壳聚糖的抑菌能力最强,且对大肠杆菌的抑制作用最强。

Study on Preparation and Antibacterial Properties of Chitosan with Different Molecular Weight

The degradation method of chitosan with hydrogen peroxide under the ultrasound was discussed.The effects of hydrogen peroxide dosage,degradation temperature,degradation time and pH on the degradation process of chitosan were researched.The degradation products were characterized by FTIR.Antibacterial properties of the degradation products against escherichia Coli,Candida Albicans and Bacillus Subtilis were studied.The optimum reaction condition with hydrogen peroxide under the ultrasound was obtained as follow: 3.0%(v/v) hydrogen peroxide of 1.0%(w/v) chitosan solution,the pH was about 5.0,the ultrasound power was 80%,and the frequency was 40kHz,the temperature was(50.0±2.0℃).Chitosan inhibited the growth of Escherichia Coli,candida albicane and Bacillus subtilis,especially Escherichia Coli.And the viscosity-average molecular weight of degraded chitosan was about 5.0×104 exhibited the strongest inhibitory effect.