Fungal biodeterioration and preservation of cultural heritage, artwork, and historical artifacts: extremophily and adaptation

Abstract

SUMMARY Fungi are ubiquitous and important biosphere inhabitants, and their abilities to decompose, degrade, and otherwise transform a massive range of organic and inorganic substances, including plant organic matter, rocks, and minerals, underpin their major significance as biodeteriogens in the built environment and of cultural heritage. Fungi are often the most obvious agents of cultural heritage biodeterioration with effects ranging from discoloration, staining, and biofouling to destruction of building components, historical artifacts, and artwork. Sporulation, morphological adaptations, and the explorative penetrative lifestyle of filamentous fungi enable efficient dispersal and colonization of solid substrates, while many species are able to withstand environmental stress factors such as desiccation, ultra-violet radiation, salinity, and potentially toxic organic and inorganic substances. Many can grow under nutrient-limited conditions, and many produce resistant cell forms that can survive through long periods of adverse conditions. The fungal lifestyle and chemoorganotrophic metabolism therefore enable adaptation and success in the frequently encountered extremophilic conditions that are associated with indoor and outdoor cultural heritage. Apart from free-living fungi, lichens are a fungal growth form and ubiquitous pioneer colonizers and biodeteriogens of outdoor materials, especially stone- and mineral-based building components. This article surveys the roles and significance of fungi in the biodeterioration of cultural heritage, with reference to the mechanisms involved and in relation to the range of substances encountered, as well as the methods by which fungal biodeterioration can be assessed and combated, and how certain fungal processes may be utilized in bioprotection.

Once upon a Time, There Was a Piece of Wood: Present Knowledge and Future Perspectives in Fungal Deterioration of Wooden Cultural Heritage in Terrestrial Ecosystems and Diagnostic Tools

“…Dust, containing both microbial contaminants and nutrients, should be regularly removed for preventive purposes. However, this practice is often underestimated [307]. In this scenario, the present spores could act opportunistically in the event of sudden environmental changes.…”

“…Thus, Aspergillus, even though it is recognized as a significant threat to cultural heritage conservation [308], should not be the only one. Indeed, by extension, so are all fungi with extreme traits such as living under drought conditions, the ability to cope with wood preservatives, growing at low temperatures, even below zero, or withstanding long periods of dormancy [133,274,307]. So that not only those fungi capable of rapid exploits deserve attention, but it also necessary to deepen our knowledge on those able to grow with little (oligotrophs) for long periods unnoticed.…”

New Biocides Based on N4-Alkylcytidines: Effects on Microorganisms and Application for the Protection of Cultural Heritage Objects of Painting

“…Microorganisms can not only be a cause of infectious diseases but also of the destruction of objects of cultural heritage [ 14 , 15 ]. Microorganisms from various systematic groups (especially filamentous fungi) capable of damaging works of art, e.g., tempera painting and oil painting on canvas, have been extensively studied in recent years [ 16 , 17 , 18 , 19 ]. There are quite a lot of compounds of various classes used to protect cultural heritage sites, but the number of antiseptics used in painting is extremely limited and has decreased significantly in recent years [ 20 ].…”

Eco-Friendly Preservation of Pharaonic Wooden Artifacts using Natural Green Products

“…Fungi have a detrimental effect on the aesthetic value of the archaeological wood due to colonization by their pigmented mycelium with the production and deposition of melanin pigment [4]. The decay caused by wood-destroying fungi belonging to Ascomycota, Basidiomycota, and Deuteromycetes, and their responsibility for the irreversible heritage loss of archaeological wooden artifacts, has been highlighted by several authors [5,6]. Their sensitivity to fungal attack and their durability can vary among wood species, and we can also note that the ancient Egyptians selected the most resistant woods to preserve their artefacts [1,7].…”

“…However, many commercial biocides are toxic, and unsafe to apply on archaeological pieces, since they can be hazardous for humans and ecosystems [8,9]. Indeed, some artificial biocides used against fungal corrosion can be degraded by fungal enzymes [6]. The preservation of archaeological wood against microbial deterioration, using products safe for the health of restorers and museum personnel, is urgent to save them from microbial damage.…”