Production of novel biocides for Cultural Heritage from Bacillus sp.

Abstract

Biodeterioration is a common problem finding in art works such as rock art caves, mural paintings and historic buildings, resulting from interactions between living organisms, specific substrate and environmental conditions [1]. Many microorganisms produce serious damage in historic materials, which are decomposed by the action of specific enzymes and organic acids produced by microbial communities. Biocide treatments are considered to be one of the practical approaches for conservation of artworks [2] however, the typical treatment is based on the application of chemical products that can present high toxicity to humans. Bacillus species are worth for treatment of these historic materials because they produce a great diversity of secondary metabolites with biological activity [3, 4]. Some strains of Bacillus subtilis have been referred to produce antifungal lipopeptides, such as surfactins, iturins and fengycins. These amphiphilic cyclic biosurfactants have many advantages over other biocides: low toxicity, high biodegradability and environmentally friendly characteristics [5]. In this study, it was produced lipopeptides from bacterial origin by means of Bacillus sp liquid cultures and evaluated the inhibitory effect of these microbial lipopeptides against biodeteriogenic fungal strains (Cladosporium sp., Penicillium sp., Fusarium oxysporum and Aspergillus niger) isolated from biodegraded mural paintings.