Proteomics of the Roseobacter clade, a window to the marine microbiology landscape.

Oceans are powered by metabolically-active microorganisms which are main drivers of global biogeochemical cycles on Earth. A decade ago, marine microbiology was boosted with next-generation sequencing capacities and the launch of large metagenomics surveys. High-performing proteomics is now comprehensive enough for reaching genome-wide and systems-wide scales. It is highly complementary to transcriptomics in order to analyze functional dynamics of marine microbes and microbial complex systems. Next-generation proteomics allows new perspectives for better understanding microbial lifestyles and uncovering the complexity of microbial communities. Here, we review the proteomics approaches and outcomes of recent work carried out on one of the most thoroughly studied marine generalist microorganisms, i.e. the Roseobacter clade, as pivotal examples. We also discuss how the study of the proteome of these organisms has helped in the understanding of the ecological strategy and lifestyle of this relevant marine clade, not only in laboratory cultures but also in its natural environment.