Microbial Community Analysis and Environmental Association in Cave 6 of the Yungang Grottoes

The Yungang Grottoes, a World Heritage Site, face biodeterioration risks. This study analyzed microbial communities in five microenvironments within Cave 6 using high-throughput sequencing (16S/18S rRNA). Communities showed high microenvironment specificity. Ascomycota and Proteobacteria dominated fungi and bacteria, respectively. Areas near the lighting window, with high external interaction, showed the highest diversity, while red pigment areas, likely under heavy metal stress, had the lowest diversity. Human-associated microbes (e.g., Escherichia-Shigella, Malassezia) indicated anthropogenic pollution on statue surfaces. Core microbiome and functional prediction (PICRUSt2) suggested high biodegradation risk in dust accumulation and inter-statue areas, enriched with organic-degrading and acid-producing taxa (e.g., Rubrobacter, Cladosporium). Microbial distribution and function were driven by openness, substrate, and human impact. This study identifies key risk zones and informs targeted conservation strategies for the Yungang Grottoes.