The team of Professor Sun Qun from the College of Life Sciences and the Center for Archaeological Science, Sichuan University published a research paper titled 'Exploring the key deteriorative microorganisms on ancient ivories unearthed from the Sanxingdui Ruins site during temporary cold storage' in the international journal Frontiers in Microbiology. By studying the bio-corrosion phenomenon found in ancient ivories unearthed from the Sanxingdui Ruins in a low-temperature and high-humidity storage environment, the key corrosive microorganisms of the unearthed ancient ivories were identified and their sources were traced. At the same time, the effect of ethanol disinfection on the microbial community of ancient ivories was explored.

The Sanxingdui Ruins are located in Guanghan City, Sichuan Province, and are a large-scale ancient cultural site with a regional central position in southwestern China. From 2020 to 2022, 6 newly discovered "sacrificial pits" unearthed nearly 13,000 numbered cultural relics, including a large number of ancient ivories. The unearthed ancient ivories have important historical, cultural, and artistic value, and the protection of cultural relics is of great significance. However, after cleaning, the unearthed ancient ivories developed microbial diseases in a temporary storage environment with low temperature and high humidity, which threatened the long-term preservation of the ancient ivories. In this paper, high-throughput sequencing technology and biochemical analysis methods were used to determine the microbial community composition and key corrosive microorganisms on the surface of unearthed ancient ivories, and the sources of these microorganisms were traced. In addition, the effect of ethanol disinfection on the microbial community of unearthed ancient ivories was evaluated. High-throughput sequencing results showed that Mortierella, Ilyonectria, Penicillium, and Aspergillus are the dominant fungi growing on the unearthed ancient ivories, while Pseudomonas, Sphingopyxis, and Perlucidibaca are the dominant bacteria. The fungi and bacteria colonized on these ancient ivories mainly originate from the surrounding soil of the ancient ivories in the "sacrificial pits". Dominant microorganisms can degrade the cellulose components on the moisturizing cotton towels of ancient ivories, making it easier to colonize on ancient ivories. Research and development found that disinfection with 75% ethanol significantly reduced the relative abundance of dominant genera such as Ilyonectria, Aspergillus, and Pseudomonas, but Mortierella became the dominant genus on ancient ivories.

The study found that Aspergillus and Penicillium are the key corrosive microorganisms of unearthed ancient ivories, and play an important role in the microbial corrosion of ancient ivories through the production of organic acids. The surrounding soil of the "sacrificial pits" is the main source of corrosive microorganisms on ancient ivories. Cleaning the residual soil on ancient ivories helps to reduce microbial colonization, but microbial contamination from personnel activities also deserves attention. The cellulose component in the moisturizing cotton towels for ancient ivories can be degraded by dominant fungi, which helps fungal colonization and growth. Non-cellulose materials can be considered for moisturizing materials in the future. Ethanol disinfection treatment will cause changes in the microbial community composition of ancient ivories. The dominant microorganisms after ethanol disinfection may cause unknown damage risks to ancient ivories, which should be an important goal of microbial control in the later stage. In addition to traditional disinfection methods such as ethanol, it is recommended to combine a variety of safe and effective methods to control the microorganisms of ancient ivories.

This research was jointly completed by Sun Qun, Yuan Haibing, Tan Xuemei, Lao Guangjie, Zhou Zhiwei, Wu Rao, Wu Wei, L眉 Shan from the College of Life Sciences and the Center for Archaeological Science, Sichuan University, and Xie Zhenbin, Wang Chong, and Liu Jiancheng from the Sichuan Provincial Institute of Cultural Relics and Archeology.