The detailed lifestyle of microorganisms in deep-sea brine environments remains largely unexplored. Using a carefully calibrated genome binning approach, we reconstructed partial to nearly-complete genomes of 51 microorganisms in biofilms from the Thuwal cold seep brine pool of the Red Sea. The recovered metagenome-assembled genomes (MAGs) belong to six different phyla: Actinobacteria, Proteobacteria, Candidatus Cloacimonetes, Candidatus Marinimicrobia, Bathyarchaeota, and Thaumarchaeota. By comparison with close relatives of these microorganisms, we identified a number of unique genes associated with organic carbon metabolism and energy generation. These genes included various glycoside hydrolases, nitrate and sulfate reductases, putative bacterial microcompartment biosynthetic clusters (BMC), and F420H2 dehydrogenases. Phylogenetic analysis suggested that the acquisition of these genes probably occurred through horizontal gene transfer (HGT). Metatranscriptomics illustrated that glycoside hydrolases are among the most highly expressed genes. Our results suggest that the microbial inhabitants are well adapted to this brine environment, and anaerobic carbohydrate consumption mediated by glycoside hydrolases and electron transport systems (ETSs) is a dominant process performed by microorganisms from various phyla within this ecosystem.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): SA-C0040, UK-C0016
Acknowledgements: The authors are grateful to Dr. Abdulaziz M Al-Suwailem and his team in the Marine Core Laboratory of the King Abdulaziz University of Science and Technology for their technical support in the field cruise and constructing experimental apparatus and the crew of R/V Aegaeo for providing technical assistance during sample collection. This study was supported by awards from the Sanya Institute of Deep Sea Science and Engineering, the Chinese Academy of Sciences (SIDSSE, CAS) (SIDSSE-201206), the National Basic Research Program of China (973 Program, No. 2012CB417304), the GRC grant (661611) of HKSAR government, and the King Abdullah University of Science and Technology (SA-C0040/UK-C0016) to PQ.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.