Surface contact disinfecting technique is a newly developed method for water sterilization．An experimental protocol to elucidate the anti-bacterial process and mechanism was proposed and applied to a novel surface contact disinfectant made of cellulose fiber grafted with DMAE-BC

using E.Coli

as a model bacterium．The minimum inhibition concentration (MIC) of the monomer

defined as a concentration at whichthe growth of E.coli.in water is completely inhibited

was determined by the plate counting method．MIC was then used as an index to characterize disinfection capability of the monomers．The disinfection mechanism of the monomer was further investigated by measuring the activity of β-galactosidase and observing the cell morphology with a scanning electron microscope (SEM)．To elucidate the disinfection process and mechanism of the grafted fiber

the steady state and dynamic adsorption of E．Coli．on the fiber as examined

respectively．The TIC-dehydrogenase activity and respiration activity of E.Coli. adsorbed on the fiber surface were also determined．The results showed that the sterilization process bythe graftedfiber was composed of two steps

in whichthe adsorption of E．Coli．bacteria on the fiber surface driven by electrostatic interaction was a fast process and cell-lysis was a relatively slow process．