ANTIMICROBIAL PROPERTIES OF QUATERNARY POLYETHYLENE IMINE

Abstract

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.