The Dingtao M2 tomb, the largest and best-preserved imperial “Huangchangticou” tomb in China, holds great significance for its conservation. Currently, varying degrees of microbial degradation are occurring on the surfaces of the M2 tomb. This study aimed to determine the microbial diversity of the M2 tomb and its surrounding environment during July 2021 and August 2022. High-throughput metagenomic sequencing revealed that the dominant fungus on the surface of the tomb chamber was Dacrymyces stillatus (DTT1) in July 2021, which changed to Talaromyces pinophilus (DTT2) in August 2022. Enzymatic activities for cellulose and lignin degradation suggested that DTT1 has high levels of manganese peroxidase, lignin peroxidase, laccase, and cellulase. The wood of the tomb contained higher levels of Fe²⁺ and Ca²⁺, and experiments with different concentration gradients of these ions in the culture medium revealed that DTT1 exhibited greater activity of cellulose and lignin degradation in environments with higher concentrations of Fe²⁺ and Ca²⁺. DTT2 degraded both cellulose and lignin. Lastly, a laboratory plate inhibition experiment demonstrated that isothiazolinone fungicide had a significant fungicidal effect on these two dominant fungi. This study provides valuable data and a theoretical basis for the preservation of the M2 tomb and other wooden cultural relics.

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.

The Jinshanling Great Wall is an important part of the Ming Great Wall, the most important material cultural heritage of China, and is currently facing a significant threat of microbial degradation due to the widespread biological weathering of open-air masonry buildings. This study focuses on the Qilin Screen Wall and Text Brick Wall of the Jinshanling Great Wall, utilizing scanning electron microscopy (SEM) and metabarcoding analyses to reveal the diverse microbial communities coexisting on the masonry surfaces, including various lichens, molds, and bacteria. Twelve fungal strains were successfully isolated. The antimicrobial experiment results indicated that 0.6% isothiazolinone-based antimicrobial BC01, 50 mg/mL carvacrol and 50 mg/mL thymol exhibited a certain degree of antimicrobial activity against these strains. Overall, this study has laid a solid foundation for microbial control of the masonry Great Wall through in-depth analysis of microbial community structure and screening of highly effective antimicrobials.

Changes in preservation conditions act as an important environmental filter driving shifts in microbial communities. However, the precise identities, functional traits, and ecological mechanisms of the dominant agents driving stage-specific deterioration remain insufficiently characterized. This study investigated microbial communities and dominant fungal degraders in waterlogged versus dried bamboo slips using amplicon sequencing, multivariate statistics, and microbial isolation. Results revealed compositionally distinct communities, with dried slips sharing only a small proportion of operational taxonomic units (OTUs) with waterlogged slips, while indicating the persistence of a subset of taxa across preservation states. A key discovery was the dominance of Fonsecaea minima (92% relative abundance) at the water-solid-air interface of partially submerged slips. Scanning electron microscopy (SEM) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) indicate that this fungus forms melanin-rich, biofilm-like surface structures, suggesting enhanced surface colonization and stress resistance. In contrast, the fungal community isolated from dried slips was characterized by Apiospora saccharicola associated with detectable xylanase activity. Meanwhile, the xerophilic species Xerogeomyces pulvereus dominated (99% relative abundance) the storage box environment. Together, these results demonstrate that preservation niches select for fungi with distinct functional traits, highlighting the importance of stage-specific preservation strategies that consider functional traits rather than taxonomic identity alone.

Dajue Temple, a representative ancient architectural heritage in North China, houses numerous lacquered wooden components of exceptional historical and artistic value. Despite their significance, this study is the first to investigate the severe dark discoloration and black spotting afflicting these lacquer surfaces—damage triggered by prolonged environmental exposure that endangers structural integrity and long-term conservation. To address this unstudied threat, we confirmed the microbial origin of black spots using ATP bioluminescence assays, then characterized microbial communities via culture-dependent methods and ITS sequencing—identifying Cladosporium spp. as the dominant biodeterio-gen driving lacquer deterioration. Functional assays on carboxymethylcellulose (CMC) and guaiacol-amended potato dextrose agar (PDA) media verified the wood-degrading potential of isolated Cladosporium spp. Antifungal susceptibility screening against ten agents demonstrates that thymol and clove essential oils achieved significant efficacy at 200 mg/mL, while nano silver gel also provided durable suppression. We proposed targeted, relic‑friendly microbial control strategies tailored for ancient lacquered wooden components. These findings provided scientific guidance for the sustainable conservation and restoration of lacquered architectural elements in historic temples and comparable cultural heritage sites. In future work, environmental monitoring should be involved, which will help to clarify microbe–environment interactions and enable early warning of biodeterioration risks.

According to our investigation carried out in July 2023, the wood of the Western Han Dynasty Dingtao M2 Tomb, stored in the preservation room, exhibited signs of microbial degradation. Our metagenomic analysis first revealed Penicillium as the dominant genus on the end of the wrapped wood. Furthermore, functional annotations demonstrated that the resident microbial community possessed cellulolytic and ligninolytic capabilities. Targeted metabolomic analysis evaluated the degradation capacity of Penicillium charlesii DTP_1, a strain isolated from the wrapped wood. We hypothesize that DTP_1 provides an acidic microenvironment via the production of organic acids; the functional microbial community then decomposes lignin into small metabolites via enzymatic action, and these products are then utilized by the microbial community, including DTP_1. Finally, we verified that liquid cinnamaldehyde and volatile gaseous allicin and carvacrol exhibit better inhibitory efficacy. Nevertheless, further optimization of plant-derived agents and application methods are still required. This study proposes a putative mechanism underlying the degradation of the Dingtao M2 Tomb wood by the microbial community, thereby providing theoretical support for the conservation of wooden cultural heritage and relics.