Prof Mitchell is the leading expert on small scale microbial processes with publications in Nature, Science and PNAS. He has given invited talks at the Masschusetts Institute of Technology, at Cambridge University and at the Gordon Research Conference on marine microbiology. He has collaborated with the University of Tokyo, MIT and the University of Chicago. His research group consists of 20+ people, including post doctoral fellows and scientific staff from all over the world. Research in his group focuses on the influences of nanometer to micrometer scale processes on microbial ecosystems. Research outcomes have been used in nanotechnology, including microfluidics and nanofabrication. As part of this research they investigate environmental viruses (>10^8/ml) and metagenomics.

Microbial Fuel Cells Microbes produce electricity at their cell membrane. This energy can be tapped to produce electricity for human use while simultaneously breaking down waste and toxic organic matter. Our research focuses on how these ecosystems function. Bacterial Motility There is little apparent reason for marine bacteria floating in the ocean to be motile. Yet, they are among the most highly motile bacteria known. Research in this lab addresses the generation of high-speed motility, its use, and the energetic and competitive costs of possessing it. Phytoplankton Dynamics Research on phytoplankton distributions traditionally occurs over kilometres. However, phytoplankton are much smaller than 1 mm. The basic ecological processes of nutrient competition, reproduction infection spread and grazing occur over distances of millimetres to a metre. Our research describes phytoplankton distributions over millimetres to centimetres and the processes that generate those distributions to understand phytoplankton ecology better. Microbial Nanopatterning The cell surfaces of marine microbes are exposed to a variety of salubrious, pathogenic and poisonous particles that range in size from salt ions to bacteria. We are testing the hypothesis that microbial surface topography helps control movement of nearby particles. In ground breaking work, Michelle Hale, has shown that diatom surfaces localise, deflect and sort submicrometre particles. These results help explain why diatoms are a dominant microalgal group in marine and freshwater environments. A spinoff from this work insight into how to control macromolecules in microfluidic flows on silicon chips. Some of this research is carried out in collaboration with Cornell Nanofabrication Facility at Cornell University.