Study on biodegradation mechanism of Fusarium solani NK-NH1 on the hull wood of the Nanhai No. 1 shipwreck.

The Nanhai No. 1 shipwreck is an ancient wooden ship in the Southern Song Dynasty. Currently, serious challenges of microbial diseases exist on the hull wood. This study aimed to obtain microbial samples from the ship hull in December 2021 and analyze the microbial diseases through scanning electron microscopy and high-throughput sequencing to preserve the Nanhai No. 1 shipwreck. The biodegradation mechanism of diseased microorganisms was explored through whole genome sequencing and the detection of enzyme activity and gene expression levels of diseased microorganisms under different conditions. The results showed that there was obvious fungal colonization on the surface of the hull wood and Fusarium solani NK-NH1 was the dominant disease fungus on the surface. NK-NH1 has strong cellulose and lignin degradation ability. Its whole genome size is 52,389,955 bp, and it contains 17,402 genes. It has a variety of key enzyme genes involved in cellulose and lignin degradation. The NK-NH1 dominant degrading enzyme lignin peroxidase has the highest enzyme activity at pH = 4, NaCl concentration of 30%, and FeSO4 concentration of 50 mg/L, while laccase has the highest enzyme activity at pH = 4, NaCl concentration of 10%, and FeSO4 concentration of 100 mg/L. The above research results prove that NK-NH1 is a key fungus to the biodegradation of ship hull wood when it is exposed to air, low pH, high salt, and rich in sulfur iron compounds. This study provides a theoretical basis for the preservation of the Nanhai No. 1 shipwreck.

Analysis of the composition of culturable airborne microorganisms in the archaeological excavation protection site of the Nanhai No. 1 Ancient Shipwreck.

After the recovery of the ship from the sea on 2007, the Nanhai No. 1 Ancient Shipwreck is currently exposed to the air. Air microorganisms settle on wooden shipwrecks, and they can use wood matrix to grow and multiply, causing biocorrosion and biodegradation. In this study, a systematical survey of the composition of culturable airborne microorganisms was performed at the conservation site of the Nanhai No. 1 Ancient Shipwreck. Airborne microorganisms were collected from seven sites in the preservation Nanhai No. 1 area over five periods. Molecular identification of the culturable microorganisms isolated from the air was done by sequencing both 16S rRNA (bacteria) and ITS (fungi) gene regions. The biodegradability of these strains was evaluated by degradation experiments with cellulose and lignin as substrate. The results showed that the composition of the isolated microbial communities was different in each period, and microbial spatial distribution was dissimilar in the same period. In the recent 2020, the dominant bacterial genus was Acinetobacter, and the dominant fungal genera were Penicillium, Aspergillus, and Cerrena. Acinetobacter spp. can degrade cellulose and lignin. Penicillium spp., Aspergillus spp., and Cerrena spp. degraded cellulose but only Cerrena spp. could utilize lignin. These dominant strains may have a harmful effect on the Nanhai No. 1 Ancient Shipwreck. This study provides data on the airborne microbial community found inside the protective chamber where Nanhai No. 1 Shipereck is placed, which can be used as a reference basis for the future conservation of the ship.

Protective effect of syringic acid via restoring cells biomechanics and organelle structure in human lens epithelial cells.

We have previously reported that syringic acid (SA) extracted from D. aurantiacum var. denneanum (kerr) may be used to prevent diabetic cataract (DC). However, the underlying mechanisms through which SA prevents DC in human lens epithelial cells (HLECs) remained unclear. In the present study, we employed single-molecule optics technologies, including transmission electron microscopy (TEM), atomic force microscopy (AFM), laser scanning confocal microscopy (LSCM) and Raman spectroscopy, to monitor the effect of SA on HLECs biomechanics and organelle structure in real-time. TEM suggested that SA improved the ultrastructure of HLECs with regard to nuclear chromatin condensation and reducing mitochondrial swelling and degeneration, which may aid in the maintenance of HLECs integrity in the presence of glucose. AFM revealed a reduced surface roughness and stiffness following SA treatment, suggesting an improved viscoelasticity of HELCs. Raman spectrometry and LSCM further revealed that these changes were related to a modification of cell liquidity and cytoskeletal structure by SA. Taken together, these results provide insights into the effects of SA on the biomechanics of HLECs and further strengthen the evidence for its potential use as a novel therapeutic strategy for DC prevention.

Analysis of Microbial Community in the Archaeological Ruins of Liangzhu City and Study on Protective Materials.

This study aims to provide a reference for the protection of the Archaeological Ruins of Liangzhu City. As a basis for the further preservation of these cultural relics, it is essential to analyze the microflora colonizing these soil objects. To do that, samples with microbial characteristics were obtained and analyzed by SEM and metagenomic sequencing to reveal the constitute of the microflora. We investigated the biodegradation of the protective material-epoxy resin by microorganisms in the Archaeological Ruins of Liangzhu City, and found that they would interact with each other, which would affect the performance of the epoxy resin. The specific mechanism of action requires further investigations. We evaluated the effect of ethyl orthosilicate on soil properties. Interestingly, we found that excess ethyl orthosilicate added to the soil of the Archaeological Ruins of Liangzhu City will cause a change in particle size and allowed the soil to condense in the laboratory. This indicates that the large use of orthosilicate may lead to intensified soil weathering, which in turn will cause soil erosion.

Fungal Community and Biodeterioration Analysis of Hull Wood and Its Storage Environment of the Nanhai No. 1 Shipwreck.

The Nanhai No. 1 shipwreck is a Chinese merchant ship in the Southern Song Dynasty, and now it is stored in a huge enclosed glass warehouse in Maritime Silk Road Museum in Guangdong Province. At present, the hull of the Nanhai No. 1 shipwreck is still being excavated, and a small part of the hull wood is soaked in a specific solution to desalt. Through long-term exploration, we found that the above two states of hull wood had undergone biodeterioration, so the purpose of this study is to analyze the fungal community of exposed and soaked wood from the Nanhai No. 1 shipwreck. We sampled 10 exposed hull wood and sea mud samples, two wood storage water samples, and air samples in the glass warehouse. We used scanning electron microscope and optical microscope to find that there were obvious fungal structures in exposed wood and wood storing water samples. High-throughput sequencing of fungi revealed that the most abundant genera in exposed and soaked wood were Fusarium sp., and Scedosporium sp., respectively. In addition, Fusarium solani and Scedosporium apiospermum were successfully isolated from the hull wood surface and wood storing water samples, and the degradation tests of lignin and cellulose, the sensitivity tests of biocides and growth curve assay were carried out. We also found that Penicillium sp. and Cladosporium sp. are the most abundant in the glass warehouse air. Our research results show that F. solani and S. apiospermum should be regarded as a major threat to the preservation of the Nanhai No. 1 shipwreck. These results provide a reference for our protection of shipwrecks and other similar artifacts.

Interaction of AR and iNOS in lens epithelial cell: A new pathogenesis and potential therapeutic targets of diabetic cataract.

Although there is significant interest in revealing the role of aldose reductase (AR) and inducible nitric oxide synthase (iNOS) in diabetic cataract (DC), the interaction of AR and iNOS remains unknown. The aim of this study is to investigate the pathogenesis mechanisms and explore as a new potential therapeutic targets for DC. This study investigated the interaction of AR-iNOS through the methods of enzyme kinetics, molecular docking and molecular dynamics simulation, co-immunoprecipitation and fluorescence resonance energy transfer (FRET). The IC50 of AR for inhibition of iNOS activity is 0.04 µM, and the IC50 of iNOS for inhibition of AR activity is 0.042 µM through enzyme kinetics; the interface showed that ARG99 on AR and GLU317 on iNOS played the key roles in the interaction of AR-iNOS predicted by molecular docking and molecular dynamics simulation. Co-immunoprecipitation of protein complexes in human lens epithelial cell (HLEC) demonstrated that AR could association with iNOS in cell; and the interaction distance of AR-iNOS was 6.50 ± 0.22 nm detected by FRET. This study exhibited a direct inhibition interaction between AR and iNOS in HLECs. It is the first report of inhibition interaction between AR and iNOS, suggesting a new pathophysiological mechanism and providing a new insight into the therapeutic mechanism of DC.