The purpose of Dr. Kerkhof’s research is to elucidate the active microbes in a variety of complex environments, and to understand the mechanisms driving this microbial diversity and biogeochemical processes. Specifically, he uses a variety of nucleic acid based analyses to identify those microorganisms (prokaryotic, archaeal, and eukaryotic) that are making ribosomes or incorporating C and N into their genomes. These microbes are by definition “active” and are controlling the biogeochemistry of the habitats in which they are found. These research efforts have focused on active bacteria in aeolian systems, in aquatic systems, in association with eukaryotic hosts, and in sediments/soils. Additionally, Lee and his group’s research spans a continuum from studies of pure cultures, to engineered systems, to field measurements. He believes that understanding the biological forces shaping microbial communities and their activity will lead to better predictions regarding the biogeochemical processes that sustain life on this planet.