Fungal bioprospecting and antifungal treatment on a deteriorated Brazilian contemporary painting.

This study aims at identifying the populations of filamentous fungi present on a Brazilian contemporary painting, whose conservation status was compromised and showed evident signs of deterioration by microbial action. In addition, to correlate the biodeterioration potential of the isolated fungal strains, cellulolytic activity testing was performed and, finally, the biocide treatment against microbial growth was carried out. A total of nine isolates of filamentous fungi were detected and three distinct taxa were identified: Aspergillus flavus, Aspergillus niger and Penicillium citrinum. The detection of the enzymatic activity of the isolates by cellulolytic plate assay revealed the potential of filamentous fungal species in causing the deterioration of paintings. Our results showed that the presence of each strain of filamentous fungi correlated with the distribution of the paint colour, suggesting a tropism of certain species for specific dyes used. In addition, strains of A. niger showed a lower enzymatic activity index, despite the aesthetic damage that this fungal specie caused on the artwork. In conclusion, this study demonstrated that the identification of the microbiota obtained from the painting may help contrasting its biodeterioration and it described a successful antifungal treatment on a contemporary art piece. Contemporary art in Brazil arose from postmodernism, through the artistic manifestations included in the Neoconcrete Manifest of 1959, as well as with the use of innovative techniques. It was a consequence of the interaction between concept and language, displayed by the artists on a set of unconventional materials and objects. Despite being a 20th century painting, the concern of the artist to keep the art object in a good conservation state has driven the realization of this work and these microbial prospecting studies, associated with artwork deterioration, may contribute to the preservation of the Brazilian contemporary heritage.

Ecology and identification of environmental fungi and metabolic processes involved in the biodeterioration of Brazilian soapstone historical monuments.

This study aimed to evaluate the action of organic acids produced by the fungal population associated with the biodeterioration process of the Twelve Prophets of Aleijadinho, a set of soapstone sculptures in Congonhas, state of Minas Gerais, Brazil. For this, samples of fungi were obtained from the surface of each of the 12 outdoor stone sculptures that comprise the set of Prophets. The identification of the colonizing filamentous fungi was performed by classical microbiology and molecular methods. Some species of filamentous fungi-dependent cultivation were detected, and the presence of species Aspergillus versicolor, Curvularia lunata, Epicoccum nigrum, Penicillium citrinum and Pseudocercospora norchiensis indicated a connection with the excretion of organic acids. The acids produced by each of these fungal species were analysed quantitatively by chromatographic methods, revealing potential biodeterioration by the action of acidic metabolites excreted in the stone. SIGNIFICANCE AND IMPACT OF THE STUDY: Minas Gerais, Brazil, is vulnerable to the activities of mineral extraction industries, posing an imminent risk to United Nations Educational, Scientific and Cultural Organization (UNESCO) recognized cities, e.g. Congonhas. Many of these municipalities hold many soapstone religious sculptures and historical monuments. Consequently, soapstone is susceptible to filamentous fungi attack causing irreversible biodeterioration. Despite the concern related to nondestructive sampling of 18th century sculptures, in this study, we have discussed the factors that lead to biodeterioration of soapstone due to organic acid excretion by the fungi that damage the stone, thereby providing an insight in conserving and preserving the soapstone monuments.