Figure 3.

An example environmental metaproteomic workflow where environmental samples are collected and extracted (gray), discovery proteomics are conducted (green), and peptide targets from selected proteins of interest can be assayed using isotopically labeled peptide standards whose taxonomic assignment can be queried against databases of genomes and metagenomes (yellow). The results can provide relative and absolute abundance measurements of the protein from the microbial and algal community, including functional and taxonomic information (blue).