Microbial diversity and composition of the Preah Vihear temple in Cambodia by high-throughput sequencing based on genomic DNA and RNA

Abstract The Preah Vihear temple is located in Cambodia and next to the border with Thailand. It was constructed in the 9th-12th centuries on a cliff 550–630 m above sea level and has become one of the UNESCO World Cultural Heritages since 2008. In this study, both DNA and RNA from the temple samples of deteriorated materials were extracted for high-throughput sequencing to analyze microbial community profile. Based on the results of bacterial 16S rRNA gene, the core phyla were dominated by Acidobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, Firmicutes, and Proteobacteria, but Proteobacteria was the only one increased significantly in RNA sequencing results among all core phyla. Specifically, the ratios of Rhizobiales and Rhodospirillales of α-Proteobacteria, Oxalobacteriaceae of β-Proteobacteria, and Myxococcales of δ-Proteobacteria showed a decrease in DNA sequencing results, but the proportion of Enterobacteriales of γ-Proteobacteria increased sharply. The genus Citrobacter of γ-Proteobacteria was the singlely dominant one in both DNA and RNA results of this study. These results indicate that there is a rich diversity in the microbiome associated with the temple sandstone, but the results were different significantly between DNA and RNA used for high through-put sequencing analysis. The results indicate a need to reveal the active members in the community based on RNA than DNA for microbial community analysis to provide meaningful information for conservation and protection.