Talaromyces saxoxalicus sp. nov., isolated from the limestone walls of the Old Cathedral of Coimbra, Portugal

Fungi are one of the main agents of stone biodeterioration worldwide, since they strongly interfere with its integrity, aesthetical and structural natural properties. During an experimental survey aimed to isolate fungal species contributing to the biodeterioration of the limestone walls of the Old Cathedral of Coimbra (Portuguese unesco World Heritage site), a Talaromyces species that could not be identified to any currently known species in this genus was isolated. Molecular phylogenetic analysis of the internal transcribed spacer, β-tubulin and RNA polymerase II subunit 2, placed this fungus in Talaromyces sect. Purpurei, while also pointing at its phylogenetic distinction from the remaining species in this section. Thus, a novel species, Talaromyces saxoxalicus sp. nov., is here proposed. Moreover, considering the isolation source of this fungus and in an attempt to understand its contribution to the overall stone monument biodeterioration, the species's in vitro biodeteriorative potential was also evaluated. The results highlighted that the species exhibited an in vitro biodeteriorative ability (calcium oxalate crystal formation), highlighting its potential deteriorative profile.