Analysis of sensitivity of E. coli to chitosan has shown thatuntreated chitosan samples did not possess antibacterial proper-ties. The number of E. coli cells following the overnight incubationwith such chitosan was comparable to that of reference whenbacteria cells are present in the physiological solution (Fig. 5). Evenmore, a slightly increased number of viable E. coli cells (5–15 fold)after overnight incubation with chitosan showed, that bacteria areable to grow on them