Biodeterioration in Art: a case study of Munch´s paintings.

Abstract

Biocolonization and biodeterioration phenomena in Cultural Heritage is presently considered a relevant issue when planning conservation strategies and preservation measures in museum collections. Artworks such as easel paintings are source of various ecological niches for microbial communities’ growth due to the presence of several organic resources. Therefore, the identification of proteinaceous materials may play an important role in the evaluation of their conservation status, in the characterisation of the artistic technique, and in the definition of compatible conservation/restoration processes. Another challenge is to understand the microbiota associated to the degradative processes when developing conservation strategies in CH artworks. For this study Edvard Munch paintings belonging to Munch Museum in Oslo presenting surface alterations were analysed to increase the knowledge about the materials used by the painter and try to understand the source and the dynamics of the associated colonising microbiota, helping in devising a conservation intervention plan. Immunoenzymatic assays was carried out in microsamples allowing the detection of casein as the binder used by the artist. The high throughput sequencing approaches allowed us to explore and characterise the microbial communities that colonise these artworks. Bacterial communities found in these artworks were mainly composed by species characterised by proteolytic capacity, an important biodeteriogenic characteristic for these paintings. Simulation assays performed in paint models prepared with casein as binder display signs of degradative action promoted by the proteolytic strains isolated from the damaged areas. This approach can be useful to promote effective intervention processes in E. Munch’s paintings with the same pathologies.