Bacterial and Fungal Diversity Inside the Medieval Building Constructed with Sandstone Plates and Lime Mortar as an Example of the Microbial Colonization of a Nutrient-Limited Extreme Environment (Wawel Royal Castle, Krakow, Poland)

Abstract

Biodeterioration is a serious threat to cultural heritage objects and buildings. The deterioration of a given material often incurs irreparable losses in terms of uniqueness and historical value. Hence preventive actions should be taken. One important challenge is to identify microbes involved in the biodeterioration process. In this study, we analyzed the microbial diversity of an ancient architectonical structure of the Rotunda of Sts. Felix and Adauctus, which is a part of the Wawel Royal Castle located in Krakow, Poland. The Rotunda is unavailable to tourists and could be treated as an extreme habitat due to the low content of nutrients coming either from sandstone plates bound with lime mortar or air movement. Microbial diversity was analyzed with the use of the high-throughput sequencing of marker genes corresponding to fragments of 16S rDNA (for Bacteria) and ITS2 (internal transcribed spacer 2) (for Fungi). The results showed that the microbial community adhered to wall surfaces is, to a large extent, endemic. Furthermore, alongside many microorganisms that could be destructive to masonry and mortar (e.g., Pseudomonas, Aspergillus), there were also bacteria, such as species of genera Bacillus, Paenisporosarcina, and Amycolatopsis, that can positively affect wall surface properties by reducing the damage caused by the presence of other microorganisms. We also showed that airborne microorganisms probably have little impact on the biodeterioration process as their abundance in the microbial community adhered to the ancient walls was very low.

Comparison of biofilm development on three building and restoration stones used in French monuments

“…and Arthrobacter agilis are associated to a rosy discoloration of stone cultural heritage (Tescari et al, 2018). Bacillus species, widespread on the studied limestones are known for their ability to withstand extreme environments and to degrade stone buildings (Kiel and Gaylarde, 2006;Scheerer et al, 2009;Dyda et al, 2019). In our study, Bacillus subtilis, developed strongly from month 14, matching with the formation of calcite crystals in needle-like structures (Loisy et al, 1999;Nguyen et al, 2019).…”

Crossiella, a Rare Actinomycetota Genus, Abundant in the Environment

“…However, the number of studies on its presence in soils and the rhizospheres of diverse plants is considerable. Several Crossiella findings in stones and building stones were also confirmed [125][126][127][128][129][130][131][132][133][134][135][136][137][138]. Finally, a few records in sea sediments and freshwaters were significant [139][140][141][142][143][144][145][146] because they included aquatic environments among Crossiella habitats.…”

Microbial Involvement in Carbon Transformation via CH4 and CO2 in Saline Sedimentary Pool

“…These results are not surprising, as 16S rRNA gene sequence libraries, constructed from DNA extracts of environmental samples, often contain a high proportion of unclassified sequences. An example are not only deep subsurface samples such as petroleum reservoirs [ 63 ], subsurface fluids [ 57 ] and brines [ 59 ], but also more available, yet scarcely known, biotopes such as sea sediments [ 64 ], floodplain meadows [ 65 ] or even heritage objects and buildings [ 66 ]. The unclassified sequences evidence the presence of a potentially unique microbial community ecology and the presence organisms with novel taxonomy, so called taxonomic “blind spots” [ 67 ].…”