Metaproteomics for Water Biotechnology: Considerations and Study Cases

This chapter summarizes the current knowledge on the practical, methodological, and interpretative aspects of applying metaproteomics in water biotechnology. We outline the full metaproteomic workflow-from sampling and protein extraction to LC-MS/MS acquisition, database construction, quantitative analysis, and bioinformatic interpretation-and emphasize critical considerations specific to complex matrices such as EPS-rich biofilms, granular sludge, and low-biomass drinking water. Case studies illustrate how metaproteomics can clarify mechanisms of micropollutant degradation, nitrogen-transforming pathways, biofilm functional architecture, and microbial resilience under operational stress. Recent advances in data-independent acquisition, metagenome-informed databases, and integrative multi-omics are shown to substantially improve depth, reproducibility, and functional resolution. Finally, we discuss emerging applications in wastewater-based epidemiology, where metaproteomics complement nucleic-acid-based surveillance by enabling the detection of large biomolecule biomarkers of population health and industrial activity. Although metaproteomics is already being applied across a wide range of water cycle contexts and is producing promising, robust results, several challenges, including limitations in analytical chemistry, database completeness, and bioinformatics workflows, continue to hinder its broader implementation. Continued technical research and innovation are therefore essential to fully unlock its potential in water biotechnology.