Microbiome Diversity and Cellulose Decomposition Processes by Microorganisms on the Ancient Wooden Seawall of Qiantang River of Hangzhou, China

Archaeological wood, also known as wooden cultural relics, refers to ancient wood that has been worked by humans. Further insights into the decomposition mechanism of archaeological wood are needed for its preventive conservation. In this study, we assessed the microbiome diversity and cellulose decomposition processes on a 200-year-old ancient wooden seawall - the Qiantang River of Hangzhou, China. We used high-throughput sequencing (HTS) to deduce the metagenomic functions, particularly the cellulose-decomposing pathway of the microbial communities, through bioinformatical approaches. The predominant cellulose-decomposing microorganisms were then verified with traditional isolation, culture, and identification method. The results showed that the excavation of archaeological wood significantly altered the environment, accelerating the deterioration process of the archaeological wood through the carbohydrate metabolism and the xenobiotic biodegradation and metabolism pathways, under the comprehensive metabolism of complex ecosystem formed by bacteria, archaea, fungi, microfauna, plants, and algae. Bacteroidetes, Proteobacteria, Firmicutes, and Actinobacteria were found to be the predominant source of bacterial cellulose-decomposing enzymes. Accordingly, we suggest relocating the wooden seawall to an indoor environment with controllable conditions to better preserve it. In addition, these results provide further evidence for our viewpoints that HTS techniques, combined with rational bioinformatical data interpretation approaches, can serve as powerful tools for the preventive protection of cultural heritage.