In contrast, chitosan saturated with oxygen demonstrated pronounced antibacterial properties(Fig. 5). When oxygen saturation was performed by anodic treatment, the number of E. coli cells (CFU) following the overnight incubation with such chitosan was about 100-fold lower comparingto that with untreated chitosan. In the case of direct oxygen saturation, the antibacterial properties of chitosan were much distinctlyexpressed. The amount of viable E. coli cells was about 3000-foldlower than that in control samples