Susceptibility of cellulose to attack by cellulolytic microfungi after gamma irradiation and ageing

In the context of broader research looking at the decontamination of books and documents stored in libraries and archives, the present paper describes the effect of different gamma-rays doses on the growth of a fungus responsible for the deterioration of paper (Penicillium chrysogenum Thom.), on cellulose paper (Whatman). Irradiation was carried out with a Co-60 source. After irradiation the samples, placed onto solid carbon free culture medium, were inoculated with conidia of F chrysogenum. After incubation at 25degreesC for 7 days fungal growth was measured by evaluating the ergosterol content. The results show that the high gamma-rays irradiation induce some alterations in the cellulose macromolecule that influence growth of the fungus responsible for paper deterioration. This phenomenon, particularly evident with the higher doses (100 and 200 kGy), is not appreciable when the irradiation dose is maintained at low levels ( < 10 kGy) suitable for a practical application of radiation technology for paper disinfection/disinfestation. The effect of accelerated ageing after gamma-irradiation on cellulose inoculated with conidia of P. chrysogenum was also tested.