Driscoll, Brian T.
Associate Professor (Microbiology); Departmental Chair
Specialization Coordinator for the Life Sciences (Multidisciplinary) Specialization
B.Sc. (McMaster University)
Ph.D. (McMaster University)
Growing up in Dundas, ON, Driscoll discovered his love of science and agriculture at a young age, thanks to the influence of two uncles - one an organic chemistry professor and the other an apple grower. Through stints as a lifeguard and swimming instructor, he discovered that teaching was something he excelled at and enjoyed. While at McMaster University, Brian became interested in molecular microbiology. He found the Rhizobium-legume symbiosis to be a fascinating area of exploration, as it allowed him to feed his interests in both agriculture and science. Driscoll came to Macdonald in 1996 as an Assistant Professor of Microbiology in the Department of Natural Resource Sciences; he teaches courses in Microbial Ecology and Bacterial Molecular Genetics. He has supervised or co-supervised more than 30 graduate students, and published extensively in peer-reviewed journals. Driscoll was part of the team that developed the Faculty’s new majors, integrating fundamental science with multidisciplinary studies, as well as being instrumental in the establishment of the Life Sciences Major for which he served as Program Director. He has been Chair of the Department of Natural Resource Sciences since September 2016.
Research is focused on understanding the exchange of nutrients that occurs between plants and bacteria during symbiotic nitrogen fixation. We are currently investigating the regulation of genes encoding enzymes involved in carbon metabolism in Sinorhizobium meliloti, the nitrogen-fixing symbiont of alfalfa. We are also interested in other aspects of microbial physiology, genetics and ecology. In my lab, we use genetic, biochemical, and molecular biological methods to answer our questions.
Rhizobia (such as Sinorhizobium meliloti) are bacteria that can form a symbiotic relationship with legume plants, including crops such as soybean and alfalfa, which are of great economic importance to Canada: symbiotic nitrogen fixation. During symbiosis, S. meliloti invades nodules that it induces on the roots of specific host plants. Within these nodules, the bacteria undergo many changes, and develop into a form known as bacteroids. Bacteroids supply the host plant with a nitrogen source, which is very important in N-poor soils or in the absence of N fertilizer. In return the plant provides the bacteria with an energy source, primarily organic acids, such as malate, which are intermediates of the tricarboxylic acid (TCA) cycle. The TCA cycle allows S. meliloti to generate the large amounts of energy required for effective symbiosis. In bacteroids, the enzymes of most of the TCA cycle enzymes appear to be expressed at much higher levels than in free-living cells.