Research progress on microbiome and organic carbon transformation in marine sediment

Abstract:

Marine sediment is the largest organic carbon reservoir on Earth, and the microorganisms thereof constitute the marine sediment microbiome which are in large quantity, widely distributed, with diversified lineages and versatile metabolic capacities. The organic carbon degradation and mineralization processes mediated by the marine sedimentary microbes not only provide material and energy for life in the sediments, but also participate in carbon cycling processes and have a significant impact on the Earth՚s climate system for long time scales. Organic carbon in sediments is gradually degraded by complex microbial metabolic activities, and its final mineralization process sequentially couples with the depletion of different electron acceptors which forms the corresponding geochemical zones in marine sediment. The study of marine sedimentary microbiome and the associated organic carbon transformation processes is important for our in-depth understanding of elemental cycling processes in sediments and further assessment of their impact on the Earth system. This review provides an overview of the quantity of the marine sediment microbiome, the diversity of microorganisms, their metabolic capacities as well as the major microbial taxa and metabolic mechanisms that forms geochemical zones. Finally, based on the current research status, the future research directions of marine sedimentary microbiome are prospected.