季铵化聚乙烯亚胺的抗菌性能研究

采用叔胺化反应与季铵化反应两步高分子反应过程,制备了季铵化的聚乙烯亚胺(QPEI);以大肠杆菌(E.coli)为致病菌体,重点研究了高分子季铵盐QPEI的抗菌活性;采用平板活菌记数法考察了季铵化度及pH值等因素对其抗菌性能的影响规律;并采用β-半乳糖苷酶活性测定法,研究了QPEI的抗菌机理.研究结果表明,QPEI具有很强的抗菌能力,对浓度为109CFU/mL的菌悬液,在药剂量为15mg/L、接触时间为4min的条件下,杀菌率可达100%;QPEI的季铵化度对其抗菌性能影响很大,季铵化度越高,抗菌性能越好;在一定的pH值范围内,pH值越高,抗菌性能越好.β-半乳糖苷酶活性测定结果表明,QPEI的抗菌机理是基于杀菌过程,而不只是抑菌作用.

ANTIMICROBIAL PROPERTIES OF QUATERNARY POLYETHYLENE IMINE

Quaternary polyethyleneimine(QPEI) was prepared via two procedures of m acromolecular reactions,tertiary amination and quaterisation,and the antimicr obial properties of this polymeric quaternary ammonium salt were mainly studied by using Escherichia Coli as a disease-leading bacterium.The effects of qua ternary degree and pH value on the antimicrobial properties were examined with the meth o d of plate counting living bacterium,and the antimicrobial mechanism of QPEI was s tudied more deeply via measuring the activities of β-D-galactosidase. The expe rimental results indicates that QPEI possesses very strong antimicrobial ability , and the antimicrobial ratio can reach 100% when QPEI is contacting with a bacter ium susp ension of 10~9 CFU/mL under the conditions of a contacting time of 4 min and a do se of 15 mg/L.The cationic degree of QPEI influences its antimicrobial propertie s to a great extent,and the higher the cationic degree is,the stronger the antimicrobi al activity.In a certain region of pH values,the higher the pH,the stronger the an timicrobial ability is.The results of measuring activities of the enzyme of β-D-galactosidase shows that the antimicrobial mechanism of QPEI is based on a st erilizing bacterium process,and is not only based a restraining action.