Microbial biofilms are a basic form of existence of bacteria in the environment, as well as in the animal and plant organisms. The patterns of biofilm formation depending on cultivation conditions is presently insufficiently studied. This paper presents experimental results on the effect of carbon sources on biofilm formation and movement on the swarming type in a phytopathogenic bacterium Pectobacterium carotovorum. A polyol inositol was shown to cause a significant activation of these processes.