Analysis of the Microbiomes on Two Cultural Heritage Sites

In the World Cultural Heritage of Leshan Giant Buddha and the West Lake area, the statues and monuments have been affected by the colonizing organisms. In the past three years, we used next-generation sequencing technology to analyze the biofilm of 14 sites in two places. The result showed that microbiomes were different on monuments, especially in terms of microbial composition, diversity, and potential functions. More phototrophic organisms and bacteria involved in the nitrogen-sulfur cycle were found in the West Lake area (WLA), while heterotrophs were discovered in the Leshan Giant Buddha area (LGBA). The biofilms on sandstone in LGBA possessed a higher alpha diversity of bacteria and fungi community than that on limestone in WLA. Biofilms in LGBA showed higher gene expression in metabolisms, such as the metabolism of carbohydrates, lipids, xenobiotics, and terpenoids. While biofilms in WLA exhibited higher levels of genetic information processing genes, which are associated with coping with harsh environments. Combine with XRD and SEM-EDS analysis, petrographic properties were considered the main factors that affect biological colonization. Environmental conditions (temperature, humidity, and precipitation) were similar in the two regions, which are suitable for the growth of organisms. Microbiome dissimilarities (beta diversity) indicated that the microbial compositions of biofilms were associated with the geographic features of the sampling sites. The stones in the two regions have their own petrographic properties that greatly influence microbiome colonization, such as microstructure, porosity, water permeability, and minerals composition.