Complex sentence: Her research group grew two microorganisms together in the lab, a "Roseobacter" clade bacterium and a photosynthetic diatom, and used changes in gene expression to identify compounds made by the diatom that were then metabolized (eaten) by the bacterium.
Split into simpler sentences: Her research group grew two microorganisms together in the lab: a "Roseobacter" clade bacterium and a photosynthetic diatom. They used changes in gene expression to identify compounds made by the diatom that were then metabolized (eaten) by the bacterium.