Bacterial Biofilm Inactivation by Gas-Discharge Plasmas

Conventional methods of killing free-living (planktonic) bacteria are often ineffective with biofilms that are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides together with some proteins and nucleic acids. The use of gas discharge plasmas represents an interesting alternative method since plasmas contain a mixture of charged particles, chemically reactive species, and UV radiation whose decontamination potential for free microorganisms is well established. Most studies of inactivation of microorganisms by plasma were carried out with microorganisms in free-living state. However, there are fewer reports about the use of plasma for biofilm disinfection or inactivation. Results on plasma-assisted biofilm inactivation are promising. However there are still some concerns that researchers coming from different fields and working on this exciting interdisciplinary topic should take into account before drawing conclusions.In this chapter, research on plasma-assisted biofilm inactivation will be reviewed. Results on the inactivation of biofilms related to oral health and food, and the application of this technique to some selected model organisms will be presented. Later some of the results of my research group will be discussed. Finally, some of the main concerns and future directions will be presented.