Despite the evident influence of the sorption of dissolved oxy-gen onto the antimicrobial properties of chitosan, it is not sufficientto protect it from microbial damage, especially in the case of longterm usage. It is extremely important in the case of beads, whoseapplication as the matrix in the columns instead of synthetic ionexchangers is desirable in many cases. We have investigated twoapproaches to enhance the antimicrobial activity of chitosan beads– additional sorption of oxygen onto chitosan beads and introduc-tion of the materials possessing biocidic action.