Chemical Properties and Microbial Analysis of Waterlogged Archaeological Wood from the Nanhai No. 1 Shipwreck

Abstract

The Nanhai No. 1 was a wooden merchant ship of the Southern Song Dynasty, which wrecked and sank in the South China Sea, Yangjiang City, Guangdong Province, China. The Nanhai No. 1 shipwreck was salvaged as a whole in 2007 and began to be excavated in 2013. During the archaeology excavation, some of the hull wood fell off the hull. These waterlogged archaeological woods (WAW) were immersed in the buffer containing EDTA-2Na and isothiazolinone K100 for moisture stabilization, preliminary desalination, and microbial inhibition. We evaluated the properties of these WAW through testing the chemical components (including lignin, holocellulose, and ash content) of the wood, and monitoring the iron element content, anion and cation content in the buffer. At the same time, the microbial composition in the desalination buffer was also detected. The results showed that the holocellulose content in these WAW were much lower than in fresh wood. The ash content in these WAW decreased after desalination treatment. The iron element content, anion and cation content in the buffer were high and kept at a certain level after desalination treatment. At the same time, the problem of biodegradation in the buffer should be paid attention to. The comprehensive protection of WAW requires to combine wood properties and microbial problems. This study provides a reference for the protection of WAW from the Nanhai No. 1 shipwreck and other similar historical wood.

Microstructural and Chemical Characteristics of Archaeological White Elm (Ulmus laevis P.) and Poplar (Populus spp.)

“…The amount of holocelluloses in hardwood species are generally between 59% to 85%, and it changes considerably at different tree age and growing location [34]. The reduction of holocellulose content in archaeological wood samples was widely reported previously [34,35,[37][38][39]. It can be due to the degradation of polysaccharides at the initial stage of the ageing process [6,34,40].…”

The Neolithic site “La Marmotta”: DNA metabarcoding to identify the microbial deterioration of waterlogged archeological wood

“…1 shipwreck ( Liu et al, 2018 ). For this typology of study whole genome sequencing ( Han et al, 2021 ) or amplicon sequencing ( Liu et al, 2017 , 2018 ; Yin et al, 2019 ; Jia et al, 2020 ) have been performed by Illumina platform. In contrast, here we report the first use of MinION amplicon sequencing, which has provided a taxonomic identification capable of assessing fungal and bacterial species related to the soft rot and erosion of waterlogged wood.…”

“…Its presence matches the previous studies conducted on waterlogged archeological wood from the Nanhai No. 1 shipwreck ( Han et al, 2021 ). The phylum Acidobacteria was also found (24.3% in F1-MARM and 4% in F2-MARM).…”

Identification of microbial diversity in buried ivory soil at the Sanxingdui site in Guanghan City, China, using high-throughput sequencing

“…Cultural relics often face corrosion and damage caused by microorganisms. Han et al (2021) analyzed the microbial composition Bacteria are widely recognized as significant contributors to the deterioration of organic cultural relics such as wooden and bone artifacts and inorganic relics such as bronze and iron in burial environments. In the case of ivory relics, bacterial corrosion often occurs through adsorption onto the surface.…”