We know that ocean microbes act like tiny biosensors, responding quickly to changes in the environment in ways that help us clean up chemical spills or treat raw sewage. But we know little about how they do it, including the genes and metabolic pathways involved. Metagenomics—the study of genetic material of microbial communities collected from natural environments—is a burgeoning field of genetic research particularly useful for the study of ocean microbes, because they’re difficult to culture in a lab. By focusing on the microbe’s RNA transcript profile, Professor Ed DeLong of MIT’s Department of Civil and Environmental Engineering, one of the pioneers of metagenomics, now brings us a step closer to identifying which genes are active under certain conditions. Read the Summer On Balance to learn more.