An increased concentration of PHMG derivatives increased bactericidal activity of the test films and inhibited biofilm formation.The film containing PHMG granular polyethylenewax (0.6e1% wt.) had the strongest bactericidal effect while the film containing PHMG stearate never had bactericidal effect. E. coli has higher biofilm formation ability than S. aureus. The most abundant bacterial biofilm was formed on the films containing PHMG salt of sulfanilic acid, the least abundant e on films containing PHMG granular polyethylene wax. The results of the evaluation of bactericidal properties of PLA and PHB composite films and biofilm formation on their surface are coherent. The films with strong bactericidal properties effectively inhibited biofilm formation while those with weak bactericidal properties failed to inhibit biofilm formation.