High diversity of fungi associated with altered wood materials in the hunting lodge of La Muette, Saint-Germain-en-Laye, France

La Muette is an eighteenth-century hunting lodge located in the forest of Saint-Germain-en-Laye, France. This study consisted in the implementation of multidisciplinary analytical tools to characterize the fungal biocontamination of woods inside the monument. The fungal colonization was first mapped by macroscopic visual observation of all the rooms. Brown rot and white rot present in different rooms and fruiting bodies of Serpula lacrymans were observed on the first and second floors in localized areas. At the same time, air sampling was carried out, and the volatile organic compounds (VOCs) specific to the activity of fungi were analysed by gas chromatography. The analysis of the VOCs confirmed the presence of active developments of moulds and S. lacrymans in the pavilion. Wood samples were collected from areas with visible fungal colonization and subjected to culturing, extraction of DNA and analysis of the ITS sequences after PCR amplification. Culturing and microscopic observation revealed the presence of several moulds: Penicillium sp., Cladosporium sp., Acremonium sp., Humicola sp., Rhizopus sp. and Mucor sp. Isolates not identified by this approach were identified by analysing ITS sequences as Trichoderma atroviride, Engyodontium album and Umbelopsis isabellina. The presence of additional Ascomycota (Acremonium charticola, Aspergillus conicus, Chaetomium elatum, Lecanicillium sp.) and of the Basidiomycota Coprinellus aff. radians was revealed after DNA extraction, amplification and analysis of ITS sequences directly on wood samples. In conclusion, a high fungal diversity including moulds, S. lacrymans and C. aff. radians was demonstrated in association with altered wood in the monument.