Microbial decontamination of lignocellulosic materials with low-temperature atmospheric plasma

One of the most important factors that influence ageing and degradation of cellulosic materials heritage objects is microbiological contamination caused by filamentous fungi. For the treatment of contaminated paper carriers disinfection and sterilization with various chemical and physical methods are used. A promising alternative to common sterilization processes for the deactivation of microorganisms is becoming the use of ionized gas, i.e. plasma. In this study, was investigated the effect of Atmospheric Discharge with Runaway Electron (ADRE plasma) generated in air, oxygen, nitrogen and carbon dioxide atmosphere on microscopic fungi Penicillium chrysogenum, Aspergillus niger, and Trichoderma atroviride applied on two kinds of test papers. The decontamination effect defined by the percentage decrease of colony forming units was observed after the few minutes of plasma treatment. Based on these results, the order of the model fungi according to increasing sensitivity was: A. niger <= P. chrysogenum < T. atroviride. The optimal parameters of ADRE plasma treatment appear as any used working gas, time of application from 0.4 to 4.5 min (the median effective dose, ED50), output of 1.24 J s(-1), and on both paper carriesrespectively in which biological decontamination was observed. (C) 2020 Elsevier Masson SAS. All rights reserved.