Metaproteomics is a powerful analytical approach that can assess the functional capabilities deployed by microbial communi-ties in both environmental and biomedical microbiome settings. Yet the mass spectra resulting from these mixed biological communities are challenging due to the high number of low intensity peak features. The use of multiple dimensions of chroma-tographic separation prior to mass spectrometry analyses has been applied to proteomics previously but can require increased sampling handling and instrument time. Here we demonstrate an automated online comprehensive active-modulation two-dimensional liquid chromatography method for metaproteome sample analysis. A high pH PLRP-S column was used in the first dimension followed by low pH separation in the second dimension using dual modulating C18 traps and a C18 column. This method increased the number of unique peptides found in ocean metaproteome samples by more than 50% when com-pared to a one dimension separation while using the same amount of sample and instrument time.