Gamma and electron beam irradiation use in the control of a radiation-resistant fungus (Epicoccum nigrum) for preservation of contaminated organic artefacts of traditional heritage

Abstract

When artefacts of traditional cultural heritage are waterlogged due to floods and other disasters, they can be quickly protected from contamination by harmful fungi using irradiation treatments. In this study, we showed that Epicoccum nigrum has the potential to contaminate traditional heritage artefacts made of Korean paper and silk under waterlogged conditions. E. nigrum showed 60% lower mycelial growth in medium containing freshwater than in medium containing natural seawater. Control of this contamination was attempted using gamma and electron beam irradiation disinfection technology. The mycelial growth of E. nigrum irradiated with a 5 kGy dose of gamma rays was completely controlled at 15 kGy dose. Next, we evaluated the effect of irradiation on contaminated sample artefacts. E. nigrum growing on waterlogged sample artefacts of cultural heritage was completely controlled at 15 kGy in freshwater-immersed artefacts of Korean paper and silk and seawater-immersed silk. However, in Korean paper immersed in seawater, 15 kGy gamma-irradiation treatment did not control growth of the fungus. Our results suggest that at least 15 kGy of gamma radiation should be used to for treatment, to preserve waterlogged traditional cultural heritage artefacts of Korea, after flooding or other disasters involving water.