Fungal-induced atmospheric iron corrosion in an indoor environment

A multi-disciplinary investigation was undertaken to determine the cause of corrosion of iron nails from a skeletal structure in a museum setting. Corroded iron nails were removed from a large whale skeleton, that had been assembled in the 1930s and exhibited for over 80 years at the Natural History Museum in London, United Kingdom. Oxford Nanopore Technologies sequencing, SEM-EDS imaging and chemical mapping were used to document the fungal and bacterial communities associated with the corrosion of the iron nails. A mechanism for indoor fungal-mediated corrosion (biodeterioration) and biomineralisation of iron is proposed. The mechanism includes the establishment of a biofilm dominated by fungi, a corrosive electrolyte produced by fungal activities, transport of ions and biomineralisation of iron-rich minerals.