Doutoramento em Bioquímica
Novel Biocides for Cultural Heritage
Mara Teresa Silva

Orientação: António Candeias & Dora Teixeira & Ana Teresa Caldeira

Many microorganisms, influenced by environmental conditions, are the main responsible for biological contamination in built heritage. Biocides based on chemical toxic compounds have been the most often used to mitigate this problem. Thus, it is of vital importance to develop proper remediation actions based on environmentally innocuous alternatives. Bacteria of the genera Bacillus are emerging as an optimistic alternative due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens.

This work aimed to develop ground-breaking research in the area of cultural and built heritage rehabilitation, by the development of natural and green safe biocides for biodegradation/biodeterioration treatment of Cultural Heritage.

A complementary methodology, including antifungal tests and molecular approaches was used, in combination with microscopic and analytical techniques to detect, characterize and study the efficiency of the biological active compounds produced by Bacillus sp. strains.

Flow cytometry allowed a comprehensive study of the physiological mechanism behind the bioactive compounds production in order to understand and improve the strategic approaches for process optimization and scale up production. Moreover, according to the results of the toxicological tests, these compounds have proven to be a real environmental safe and innocuous alternative to the chemical biocides commonly used during the conservative interventions. Thus, they have shown a great potential for their future application in cultural and built heritage rehabilitation.

Keywords: Biodegradation/Biodeterioration, Bacillus sp., Bioactive compounds, Lipopeptides, Iturin, Antifungal activity, Sporulation, Green Biocides, Cultural Heritage rehabilitation