Abstract
Gamma radiation is a safe and effective technique for the treatment of art collections being used with high efficiency in reducing microbial loads being obtained by the emission of a radioactive isotope, such as Cesium 137. Portinari's work, from the collection of the National Museum (Brazil), was analyzed and the fungi contained therein were collected, isolated, and further treated with gamma radiation for decontamination. Radiation doses used were 16, 19 and 22 kGy. Results indicated 11 genera and 17 species isolated. Penicillium and Cladosporium were isolated in air, artwork and its support - emphasizing the predominance they assume in the contamination of works of art under favorable conditions, such as museums. The genera Penicillium, Cladosporium, Nigrospora and Curvularia showed high resistances (16 kGy). The most resistant was Cladosporium, which showed no growth under 22 kGy. As there are some differences in ionizing radiation resistance among fungi from the same order or species, the results here outlined indicates that the rates of DNA damage and repair were critical, depending on chronic or acute dose irradiated. The biochemical mechanism acting on fungal cells under irradiation was basically the inactivation of specific enzymes and, probably, DNA damage, particularly stimulating double-strand breaks.
Identification of Fungi Resistant to 137Cs Gamma Radiation From an Artwork by Candido Portinari
