Susceptibility to fungal deterioration of an ancient monoxyl and a medieval shipwreck under postexcavation environmental stress

An archeological discovery, a well-preserved ancient monoxyle dated from the first century BCE to the first century CE and a fifteenth- to seventeenth-century shipwreck, excavated at the Drmno open-pit coal mine, created a unique opportunity for the fungal-induced deterioration of newly excavated archaeological wooden artifacts to be studied in Serbia for the first time. The monoxyle was carved from a single tree trunk of Pinus nigra or Pinus sylvestris , while two shipwreck wooden samples were shown to be Castanea sativa and Quercus (White Oaks group). Despite identical semihypogean conditions favorable for fungal colonization, the artifacts responded differently: the monoxyle showed extensive decay, predominantly by the brown rot fungus Coniophora puteana , with additional symptoms linked to Mortierellaceae and Niesslia sp., while the shipwreck lacked visible damage, although microscopic evidence revealed Niesslia , Cephalotrichum , and other fungi. Based on the documented fungal structures, both objects have, to an extent, shared a deteriogenic mycobiome. Most of the fungi documented on monoxyle and shipwreck are associated with soft rot, or are often linked with decayed wood. Likewise, many observed species are known to be associated with archeological wooden artifacts and to produce an array of lignocellulolytic enzymes, while the up-to-date published literature suggests that this is the first report of soft rot fungi Microascus melanosporus and Pseudogymnoascus sp. being documented on archeological wood. Understanding the site-specific fungal communities and the environmental conditions to which the objects are exposed, and identifying the wood species of artifacts, are crucial, as this information directly informs the selection of appropriate and effective conservation techniques, ensuring the long-term preservation of invaluable wooden artifacts.