HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Joaquin, J. C. Articles by Brelles-Mariño, G. Search for Related Content PubMed PubMed Citation Articles by Joaquin, J. C. Articles by Brelles-Mariño, G. Agricola Articles by Joaquin, J. C. Articles by Brelles-Mariño, G.

Is gas-discharge plasma a new solution to the old problem of biofilm inactivation?

¹ Biological Sciences Department, California State Polytechnic University, 3801 W. Temple Avenue, Pomona, CA 91768, USA
² Physics Department, California State Polytechnic University, 3801 W. Temple Avenue, Pomona, CA 91768, USA
³ Center for Macromolecular Modeling and Materials Design (CM³D), California State Polytechnic University, 3801 W. Temple Avenue, Pomona, CA 91768, USA

Correspondence
Graciela Brelles-Mariño
gbrelles{at}csupomona.edu

Conventional disinfection and sterilization methods are often ineffective with biofilms, which are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides. The use of gas-discharge plasmas represents an alternative method, since plasmas contain a mixture of charged particles, chemically reactive species and UV radiation, whose decontamination potential for free-living, planktonic micro-organisms is well established. In this study, biofilms were produced using Chromobacterium violaceum, a Gram-negative bacterium present in soil and water and used in this study as a model organism. Biofilms were subjected to an atmospheric pressure plasma jet for different exposure times. Our results show that 99.6 % of culturable cells are inactivated after a 5 min treatment. The survivor curve shows double-slope kinetics with a rapid initial decline in c.f.u. ml^–1 followed by a much slower decline with D values that are longer than those for the inactivation of planktonic organisms, suggesting a more complex inactivation mechanism for biofilms. DNA and ATP determinations together with atomic force microscopy and fluorescence microscopy show that non-culturable cells are still alive after short plasma exposure times. These results indicate the potential of plasma for biofilm inactivation and suggest that cells go through a sequential set of physiological and morphological changes before inactivation.