Metaproteomic Dataset on Semi-Diurnal Variability of the Bacterioplankton Communities During a Spring Phytoplankton Bloom in the North Sea.

Phytoplankton blooms create a substrate-rich environment that supports the growth of bacterial planktonic heterotrophs. Previously, we studied the dynamics of such bacterioplankton at a long-term ecological research site near the coast of Helgoland Island (North Sea) once a day. Here, we present a novel dataset (available under the PRIDE-ID: PXD055396) indicating significant differences at the protein level in a semi-diurnal analysis. Using metaproteomics, we studied changes in the free-living (0.2-3 µm) bacterial community that occurred between early (7 am) and late (9 pm) sampling over 3 days. The results highlight the sensitivity, robustness, and reproducibility of mass spectrometry-based metaproteomic analyses to assess changes in the activities of the bacterioplankton communities. Taxonomic analyses revealed significant changes in the abundance of 65 bacterial genera. Particularly, proteins from the flavobacterial genera Candidatus Prosiliicoccus and Aurantivirga were significantly more abundant in the late samples. This comprehensive dataset highlights semi-diurnal changes in bacterial community composition and metabolic activity during a phytoplankton bloom that would have remained undetected with a once-per-day sampling approach.