Akademska digitalna zbirka SLovenije - logo
E-resources
Full text
Peer reviewed Open access
  • Centimetric circular areas ...
    Cicardi, Marta; Bernasconi, Davide; Martire, Luca; Pastero, Linda; Caneva, Giulia; Favero-Longo, Sergio E.

    International biodeterioration & biodegradation, January 2024, 2024-01-00, Volume: 186
    Journal Article

    This study investigated the poorly known phenomenon of Centimetric circular areas Uncolonized by Microbial Biofilms (CUMBs) which is frequently observed on natural and heritage stone surfaces displaying widespread lithobiontic colonization. In order to unveil a possible relationship with past lichen colonization, analyses were carried out on the distribution, morphometry, physical and mineralogical properties, and microscopic features of CUMBs on the marble surfaces of a balustrade in the Garden of a Savoy residence in Torino (Italy; UNESCO-WHS 823bis) and in its original quarry site in the W-Alps. Image analyses of CUMBs displayed a distributional and dimensional compatibility with lichen thalli (re-)colonizing surfaces in their vicinity. Invasive analyses on quarry materials displayed similar microscopic modifications in marble layers beneath CUMBs and lichens, associated to a higher stabilization of the calcite {01–12} form, which is favoured by the presence of organic substances. These findings support the hypothesis of a lichen origin for some CUMBs, which may derive from the modification of physical stone properties and/or a long-lasting allelopathic effect affecting surface bioreceptivity. Display omitted •CUMBs and lichens compared on natural and heritage marble surfaces.•Distributional and dimensional compatibility of CUMBs and lichens.•Similar micro-features beneath CUMBs and lichens associated to calcite reprecipitation.•Experimental evidences pointing to a lichen origin of (some) CUMBs.•Reduced CUMBs bioreceptivity due to modified physical properties and/or allelopathy.