Metaproteomics in the Study of Marine Microbial Processes: Opportunities in Ocean Research and Diagnosis

Proteins are abundant biomolecules that serve key functions in marine microbial communities, such as enzymes catalyzing biogeochemical reactions and transporters acquiring scarce nutrients. The measurement of proteins in biologically diverse microbial communities, such as those in ocean environments, is called metaproteomics. In recent years, metaproteomics methodologies have matured into powerful and practical approaches that contribute valuable functional and diagnostic information about microbial physiology, metabolism, and biogeochemistry. In this review, we introduce the conceptual foundations and methodological principles of marine metaproteomics; discuss current applications in marine microbiology, ocean biogeochemistry, and ecosystem diagnosis; and evaluate emerging frontiers, including quantitative stoichiometric inference, biomarker development, and global-scale interoperability. We argue that metaproteomics has reached a pivotal stage: poised not only to complement other meta-omics approaches but also to become an accessible central tool for diagnosing marine ecosystem function and understanding microbial responses to environmental change.