Marine metaproteomics: deciphering the microbial metabolic food web

•Metaproteomics helps us discover and learn about metabolic processes in the ocean, including novel pathways.•Insight has been gained regarding microbial interactions and hypothetical proteins.•Metaproteomics provides ‘first insight’ for new and difficult-to-study marine systems.•Metaproteomics is synergistic when coupled with marine metagenomics.

Metaproteomics can be applied to marine systems to discover metabolic processes in the ocean. This review describes current breakthroughs regarding marine microbes in the areas of microbial procurement of nutrients, important and previously unrecognized metabolic processes, functional roles for proteins with previously unknown functions, and intricate networks of metabolic interactions between symbiotic microbes and their hosts. By recognizing that metaproteomics empowers our understanding of the roles that marine microbes play in global biogeochemical cycles, the achievements to date from this advancing field highlight the enormous potential that the future holds.