Project description:Sulfur metabolism in the deep-sea cold seep has been mentioned to have an important contribution to the biogeochemical cycle of sulfur in previous studies. And sulfate reducing bacteria have also been considered to be a dominant microbial population in the deep-sea cold seep and play a crucial role in this process. However, most of sulfate reducing bacteria from cold seep still cannot be purely cultured under laboratory conditions, therefore the actual sulfur metabolism pathways in sulfate reducing bacteria from the deep-sea cold seep have remained unclear. Here, we isolate and pure culture a typical sulfate reducing bacterium Desulfovibrio marinus CS1 from the sediment sample of the deep-sea cold seep in the South China Sea, which provides a probability to understand the sulfur metabolism in the cold seep.
Project description:Zero-valent sulfur (ZVS) distributes widely in the deep-sea cold seep, which is important immediate in the active sulfur cycle of cold seep. In our preview work, a novel ZVS formation pathway discovered in the deep-sea cold weep bacterium Erythrobacter flavus 21-3 was described. However, whether this pathway worked and what function roles it played in the cold seep were unknown. In this study, E. flavus 21-3 was verified to produce zero-valent sulfur in the cold seep using genes soxB and tsdA as our preview report described. Based on proteomic data, stoichiometric methods and microscopic observation, this ZVS formation pathway benefited E. flavus 21-3 in the deep-sea cold seep. Notably, 30% metagenomes contained these two genes in the shallow sediments, which present the most abundant sulfur genes and active sulfur cycle in the cold seep sediments. It suggested that this sulfur formation pathway exist across many bacteria in the cold seep. This strongly indicates that this novel pathway might be frequently used by microbes and plays an important role in the biogeochemical sulfur cycle in cold seep.
Project description:The prognosis of liver cancer was inferior among tumors. New medicine treatments are urgently needed. In this study, a novel exopolysaccharide EPS364 was purified from Vibrio alginolyticus 364 which was isolated from South China Sea cold seep. Further research suggested that EPS364 consisted of mannose, glucosamine, gluconic acid, galactosamine, arabinose with a molar ratio of 5:9:3.4:0.8:1.5. The molecular weight of EPS364 was 14.8 kDa. Our results further indicated that EPS364 was β-linked and phosphorylated polysaccharide. Notably, EPS364 exhibited significant anti-tumor activity. Besides, EPS364 induced Huh7.5 cells apoptosis, collapse of mitochondrial membrane potential (MMP) and generation of reactive oxygen species (ROS). Proteomic and quantitative real-time PCR analyses indicated that EPS364 blocked cancer cell adhesion and induced apoptosis via targeting FGF19–FGFR4 signaling pathway. These findings suggested that EPS364 was a promising anti-tumor agent for pharmacotherapy.
2021-09-09 | PXD023080 | Pride
Project description:microbial diversity of cold seep in South China Sea
| PRJNA917276 | ENA
Project description:Microbial Diversity in cold seep of South China Sea