Baseline characteristics of the microbial community structure and composition of the world cultural heritage sites in Macau

Abstract

Microorganisms contribute to the deterioration of materials. In this study, samples were collected from the surfaces of different cultural heritage sites in Macau to reveal the structure and composition of microbial communities and to understand the deterioration mechanisms, which will be helpful in developing strategies to manage and protect these sites. Structure and composition of microbial communities on the surfaces of different types of cultural heritage in Macau, including ceramic-tile walls, architectures in park, and historic buildings, were analyzed by conducting 16S rRNA gene sequencing. Cyanobacteria, Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, and Bacteroidetes were found to be most abundant microbial phyla on the surfaces of these cultural heritages of Macau under subtropical conditions. Among them, Cyanobacteria was observed as the dominant microbial phylum, indicating its potential role as a key microbial group responsible for the deterioration of cultural heritages. Significant variations were also observed in the distribution of microbial groups among different surface samples. Shannon index values revealed that microbial communities on the walls of historic buildings were more diverse than those on stones and ceramic tiles. Additionally, the distribution of microorganisms within Macau's cultural heritage sites was intricately linked to temperature, humidity, and climate. The results emphasize the importance of identifying the composition of surface microbial communities for a better understanding of biodeterioration process to protect and manage the cultural heritage sites.