Microbial activity is one of the most important processes to mediate the flux of organic carbon from the ocean surface to the seafloor.However,little is known about the microorganisms that underpin this key step of the global carbon cycle in the deep oceans.Archaea are ubiquitous and abundant in the deep oceans yet the metabolism and biogeochemical functions of many groups remain enigmatic because they have eluded cultivation.Here we present genomic and transcriptomic evidence that five ubiquitous archaeal groups actively use proteins,carbohydrates,fatty acids and lipids as sources of carbon and energy at depths ranging from 800 to 4950 m in the pelagic ocean across three different ocean basins.