Fungal biodeterioration of historical library materials stored in Compactus movable shelves

Mold deterioration of historical library materials in archives and libraries is a frequent and complex phenomenon that may have important economic and cultural consequences. Compactus shelving is one of the systems utilised for the conservation of library materials, because it allows for a more efficient use of space and protection against dust deposition. However, in the last ten years there have been many reports on single species mould infections within Compactus shelves in spite of conventional control of environmental temperature and humidity to recommended standards. Contamination was commonly characterized by white spots of mycelium, measuring 0.5–1.0 cm in diameter and observed on volume binding, especially those of leather, parchment or textile. Until now, the identification of the causal agent at species level has not been reported since attempts to grow it on media for subsequent identification were unsuccessful. Using a range of sampling techniques, including adhesive tape and nitrocellulose membrane, and a combination of conventional culturing methods, direct microscopic observations and molecular methods, we have for the first time identified to species level the fungus causing infections inside Compactus shelves.

► First report of Eurotium halophilicum as the causal agent of fungal contamination in libraries and archives in Italy.
► Compactus movable shelves as a new manmade niche for E. halophilicum.
► Identification at species level using a combination of conventional and biomolecular techniques.