PLANT EXTRACTS AS GREEN POTENTIAL STRATEGIES TO CONTROL THE BIODETERIORATION OF CULTURAL HERITAGE

The biodeterioration of historic-artistic manufacts is related to several biological systems, including fungi and bacteria, whose metabolic activities and vegetative development have a direct consequence on the conservation of cultural assets. Generally, different chemical compounds are utilized as biocides in order to control biodeteriogens growth, but recently the attention has been focused on potential risks of their use towards human health (operators, visitors) and the environment. In order to develop alternative methods, various natural products have been tested, particularly to control the colonization by fungi and bacteria. In this study, antimicrobial activity of three different plant products, Tea tree essential oil, Calamintha nepeta and Allium sativum L. extracts, has been evaluated against Bacillus subtilis, Micrococcus luteus, Penicillium chrysogenum and Aspergillus spp. (previously isolated from colonized artworks) through three different in vitro antimicrobial assays (microdilution in microtiter plates, well plates diffusion and agar disc diffusion method). The bioassays show a different microbial susceptibility to plant extracts, establishing for each bacteria and fungi the Minimum Inhibitory Concentration (MIC) and defining the diameter of the growth inhibition area. This result supports the data reported in literature and shows an important potential suggestion for the possible use in the control of biodeterioration of cultural heritage, safe both for human health and environment.