The research work presented at the REHABEND 2022 Congress delves into the assessment of patina formation, staining, and biofilm formation on historic structures, focusing on the origins of these phenomena, whether geochemical or biogenic. The study aims to raise awareness among relevant entities about the necessity of regular diagnostic and conservation-restoration campaigns for such structures to preserve their cultural and aesthetic significance for future generations.
Emphasising the importance of monitoring, preventive plans, and mitigation strategies, the research advocates for the use of new consolidant solutions and natural mitigation products, such as natural biocides, as environmentally friendly alternatives to conventional products.
The study employs advanced techniques like X-ray microdiffraction and scanning electron microscopy to characterise the microbial populations colonising the Convent “São João da Penitência” and assess their impact on the building’s deterioration. Results indicate the predominance of eukaryotic colonisers and the presence of prokaryotic strains like Bacillus and cocci, with Proteobacteria, Actinobacteria, and Cyanobacteria being the major phyla identified. Cultivable fungi include black yeasts and genera like Rhodotorula and Aspergillus.
The methodology involves in-situ imaging using digital microscopy and spectrophotometry to measure colour changes, reflecting the aesthetic impact of the building’s deterioration. Microbial isolates are obtained and characterised for future studies, while a metagenomic approach based on Next Generation Sequencing is used to analyze the total microbial population in the sampled areas.
Overall, the research sheds light on the complex interplay between environmental factors, microbial colonisation, and stone deterioration in historic structures, advocating for sustainable conservation practices and the adoption of innovative, environmentally friendly solutions for long-term preservation.
