Current Knowledge on the Fungal Degradation Abilities Profiled through Biodeteriorative Plate Essays

Abstract

Fungi are known to contribute to the development of drastic biodeterioration of historical and valuable cultural heritage materials. Understandably, studies in this area are increasingly reliant on modern molecular biology techniques due to the enormous benefits they offer. However, classical culture dependent methodologies still offer the advantage of allowing fungal species biodeteriorative profiles to be studied in great detail. Both the essays available and the results concerning distinct fungal species biodeteriorative profiles obtained by amended plate essays, remain scattered and in need of a deep summarization. As such, the present work attempts to provide an overview of available options for this profiling, while also providing a summary of currently known fungal species putative biodeteriorative abilities solely obtained by the application of these methodologies. Consequently, this work also provides a series of checklists that can be helpful to microbiologists, restorers and conservation workers when attempting to safeguard cultural heritage materials worldwide from biodeterioration.

Biodeterioration of Salón de Reinos, Museo Nacional del Prado, Madrid, Spain

“…In light of the obtained data, the species with potential biodeterioration properties mainly belong to the genera Bacillus, Priestia, Cladosporium, and Penicillium, as described in other reports [2][3][4][5]. In addition, it should be noticed that airborne microorganisms, commonly isolated from plants, are able to use lipids and casein from mural paintings as nutrient sources and therefore represent a risk for mural paintings.…”

“…Trovão and Portugal [5] described the importance of using plate assays for identifying the deteriorative abilities of microorganisms in order to evaluate the potential risks to mural paintings. The isolation of microorganisms and plate assays are widely used by microbiologists in deterioration studies to provide insight into their attack on different types of materials [5,14,26,[52][53][54][55].…”

“…Trovão and Portugal [5] described the importance of using plate assays for identifying the deteriorative abilities of microorganisms in order to evaluate the potential risks to mural paintings. The isolation of microorganisms and plate assays are widely used by microbiologists in deterioration studies to provide insight into their attack on different types of materials [5,14,26,[52][53][54][55]. Table 5 presents the metabolic activities of the isolates and their role in the hydrolysis of gelatin, casein, and lipids, the solubilization of gypsum and calcite, and acid production (Figure 3).…”

“…Subsequently, the cells and hyphae penetrate the paint layer, and the chemical attack results in pitting, peeling, cracking and loss of paint. To this damage is added that caused by microbial metabolites, which alter the original color and sometimes produce red, green or black pigmentations [1][2][3][4][5].…”

Black Fungi and Stone Heritage Conservation: Ecological and Metabolic Assays for Evaluating Colonization Potential and Responses to Traditional Biocides

“…To date, very little information is available on their sensitiveness to biocides and on their metabolic and eco-physiological profile, mainly limited to a few model fungi [28,29]. In this light, traditional culture dependent assays can be useful to deepen in detail their ecological traits and biodeteriorative potential [30].…”