Bacteroidetes contribute to the carbon and nutrient cycling of deep sea through breaking down diverse glycans

Abstract

Bacteroidetes are thought to be specialized for the degradation of algae-derived ocean polysaccharides and are a major contributor to the marine carbon and nutrient cycling. Here, we first show Bacteroidetes are the second most abundant phylum bacteria in deep-sea cold seep and possess more genes associated with polysaccharides degradation than other bacteria through metagenomics methods. We further isolate a novel Bacteroidetes species, Maribellus comscasis WC007T, which can efficiently degrade numerous different polysaccharides including: cellulose, pectin, fucoidan, mannan, xylan and starch. These results are verified by transcriptomic analyses and growth assays. Notably, we find cellulose promotes abundant bacterial growth, and using transcriptomics and metabolomics we finally report on the underlying mechanisms of cellulose degradation and utilization, as well as potential contributions to the carbon cycling. Overall, our results suggest Bacteroidetes play key roles in the deep-sea carbon and nutrient cycling, likely due to their high abundance and prominent polysaccharide degradation capabilities.

Dynamics and Controls of Methane Oxidation in the Aerobic Waters of Eastern China Marginal Seas

“…It has been long recognized that the annual release of methane from the YS and ECS account for a disproportionate contribution to global ocean emissions (Ye et al, 2019;Zhang et al, 2004;Zhang, Zhang, Ren, et al, 2008b). Indeed, the average sea-to-air flux was 8.5 ± 21.9 μmol m 2 d 1 in our study, higher than the previous data documented in the ECS and YS during spring (Zhang et al, 2004;Ye et al, 2016;Zheng et al, 2020). These fluxes were also lower than the reported values in the coastal waters of German Bight (Bussmann et al, 2021), where much higher methane concentrations were observed.…”