Complex
of chitosan acetate (CSAC) with C12–C18 alkyl amido prophyl dimethylamine
betaine (AAPDB) was prepared and characterized by Fourier transform-infrared
(FT-IR), thermal analysis (TG, DTG and DSC), X-ray diffractogram. Results
showed that complex formed mainly by the electrostatic interaction between NH3t
of CSAC and COO2 of AAPDB. Minimum inhibitory concentrations (MICs) were
evaluated against E. coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853,
Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis and Candida
albicans. Results showed that CS/AAPDB solution could or even more strongly
inhibit growth of all the tested microorganisms, whereas CSAC could not inhibit growth of C.
albicans and AAPDB could not inhibit growth of S. epidermidis, E. coli, P.
aeruginosa. Relative inhibition times (RITs) of CS/AAPDB solutions with
different concentration and ratio of CSAC and AAPDB were also investigated
against the five microorganisms. Results showed that CS/AAPDB solutions with
CCSAC t CAAPDB of 0.05% t 0.015%, 0.05% t 0.0075%, and 0.025% t 0.0075% showed
higher antimicrobial activity. The relationship between complex formation and
antimicrobial activity was discussed.
