The marine subsurface biosphere
The Amend lab is part of the Center for Dark Energy Biosphere Investigations (C-DEBI), an NSF-funded Science and Technology Center. This Center is built on compelling evidence that the microbial abundance in subseafloor sediments equals that in the overlying ocean. C-DEBI also targets another subseafloor biome—the igneous crust, which is the largest aquifer system on Earth. Most of this system is hydrologically active, carrying heat, solutes, genetic material, microbes, spores, and viruses. C-DEBI is a multi-institutional research network that seeks to develop an integrated understanding of microbial subseafloor life at the molecular, cellular, and ecosystem scales. The approaches balance field exploration and discovery with laboratory investigations, modern analytics, and numerical modeling. The Amend lab is involved in projects to a) map the geochemical energy sources in subseafloor ecosystems at a range of spatial scales, b) develop and test coupled geochemical-microbial models of subseafloor ecosystems, c) determine metabolic activity of subseafloor microbial communities, d) isolate and characterize novel bacteria and archaea from diverse subseafloor habitats, and e) examine fundamental physiology of subseafloor microbes under conditions of low growth rates and low energy flux.