Sandstone Conservation of Polish Tomb Chapel and Its Effect on Microbial Diversity

Abstract

ABSTRACT Sandstone deterioration is one of the main problems affecting historical monuments. Therefore, to protect cultural heritage structures, introducing conservation strategies is necessary. The study aimed to assess bacterial and fungal diversity of non-hydrophobized and hydrophobized areas in the historic tomb chapel of Karol Scheibler in Poland after 10 years of the conservation treatment. The applied conservation treatment included hydrophobization with the Polish impregnates Konsil Z. Next-generation sequencing (NGS) exhibited significant changes in the microbial communities of the treated sandstones. Members belonging to the phylum Acidobacteriota, Chloroflexi, and Verrucomicrobiota and genera Pseudonocardia, Synechococcus, Rubrobacter, Bryobacter, Blastocatella, and Truepera showed significantly lower relative abundance in hydrophobized area. Moreover, fungi Ascomycota, mainly class of Dothideomycetes, were significantly less abundant in the hydrophobized samples—could be due to hydrophobization. However, some groups of microorganisms enhanced their relative abundance in hydrophobized area. These groups of bacteria such as Proteobacteria, Gammaproteobacteria, Rhizobiaceae, and Nocardioides could have caused the appearance of a green bloom on the sandstone 10 years after the impregnation.