The importance of microbial mediation in the biogeochemical cycles of the ocean is well documented. A major source of marine metallic minerals exists as ferromanganese (polymetallic) nodules in the deep ocean (4,000-5,000 m deep). Composed predominantly of iron, manganese, copper, nickel, and zinc, these nodules play a key role in governing the biogeochemical availability of many of these metals in the global ocean. While it is assumed that microorganisms mediate some of the processes that form nodules, it is poorly constrained as to which organisms mediate these processes or how these processes in turn may support microbial metabolisms. We propose using fingerprinting and sequencing methods to examine the microbial community diversity of organism associated with ferromanganese nodule collected from the South Pacific Gyre. Further, because many of the microbial organisms present in the deep-sea are novel and uncultivated, we plan to perform metagenomic analysis to link phylogenetic identity with physiology, with the goal of generating (near-)complete environmental genomes. The proposed research will be the first attempt to determine how the microbiology of deep oceanic nodules shape and are shaped by the environment.