The identification of microorganisms involved in biodeterioration/biodegradation process is determinant to understand their effects on cultural assets, and furthermore, it is a crucial step to define an efficient strategy to protect monuments and artworks from microbiological recolonisation, in order to promote its preservation. The renaissance mural paintings from the garden of the Inquisition Palace in Évora, classified by UNESCO as World Heritage, were analysed in order to find the microbial population involved in the biodeterioration process, and, to assist and develop an efficient intervention, by biocides application to control the propagation of microbial communities responsible for biodegradation. The biocides tested revealed good inhibition results against the microbial communities isolated from the paintings, whose action spectrum was noticeably enlarged when the application was carried out combining two different commercial biocides. In vitro antifungal assays performed with new natural biocompounds revealed efficient inhibition capacity, suggesting the potential of these compounds to be used as a great and safe alternative to the chemical compounds usually used on cultural assets microbial treatments

In recent years, the population has become acutely aware of the need to conserve the world’s resources. The study of new compounds produced by natural means is important in the search for alternative green solutions that act against biodeteriogenic fungi, which promote biodeterioration of built cultural heritage sites. The present paper reports new solutions, derived from Bacillus sp. CCLBH 1053 cultures, to produce lipopeptides (LPP) that can act as green biocides to promote the safeguarding of stone artwork. In the stationary phases of bacteria growth, peptone supplementation and sub-lethal heat activation improve the second cycle of sporulation, greatly enhancing LPP production. The bioactive compounds produced by Bacillus cultures suppress biodeteriogenic fungi growth on stone materials, and, hence, provide an important contribution to the development of new biocides for cultural heritage rehabilitation.