Metagenomics of the Surface of an Architectural Heritage Site: A Case Study of the Ji Family’s Residence in the Southeast of Shanxi Province, China

Microbial corrosion poses a significant threat to architectural heritage worldwide. This study used metagenomics to investigate microbial diversity and taxonomic groups present in the door walls of the Ji family’s residential houses, as well as their biological functions and chemical cycles. Taxonomic annotation revealed the predominant microbial taxa associated with wall corrosion, shedding light on their potential impact on structural integrity. Moreover, analyzing the metabolites and pathways present in these microbial communities allows for a thorough understanding of their functional capabilities. Our results revealed that areas with significant damage (dwelling bad door (DBD) and dwelling bad wall (DBW)) exhibited a higher microbial diversity compared to undamaged areas (dwelling good door (DGD) and dwelling good wall (DGW)), with variations in the occurrence of archaeal and bacterial species. The presence of bacteria was found to be connected with impaired function in DBW, whereas changes in the community patterns of Sphingobium and Sphingomonas, as well as a decrease in Cercospora proportion and an increase in Fusarium proportion, were correlated with damage in DBD. Both the Entner–Doudoroff (ED) route and sulfide oxidation processes were observed in both damaged locations (DBD and DBW). However, significant nitrogen-cycling mechanisms, including dissimilatory nitrate reduction to ammonium, were only found in DBW. Furthermore, DBD specifically detected the shift from methyl mercaptan (MMPA) to methyl mercaptan (MeSH). This research highlights the intricate interplay between microbial communities and the physical deterioration of residential structures, emphasizing the importance of understanding microbial ecology in mitigating such issues.