Year Awarded: 2020
Research Lab: Jose Dinneny
Christopher Dundas received his B.S. in Chemical Engineering (’15) with a minor in Biotechnology at the University at Buffalo. He received his Ph.D. (’20) in Chemical Engineering at the University of Texas at Austin, under the guidance of Dr. Benjamin Keith Keitz. During his doctoral training, Christopher studied and engineered electroactive soil bacteria – a unique class of microbes that can directly convert carbon sources into electrical energy. Using techniques in materials science and synthetic biology, he demonstrated that bacterial electron transfer can control the formation of a variety of functional organic and inorganic materials. Christopher also developed genetic tools that increase the programmability and responsiveness of bioelectrical behavior.
Developing Design Rules for Soil Carbon Input at the Root-Rhizosphere Interface
Soil can have an enormous impact on climate change mitigation, as atmospheric CO2 is captured and stored in large quantities by soil organic matter. Plants mediate carbon sequestration by transferring aboveground photosynthesis products to belowground roots. This carbon is stabilized into soil pools by root growth/biomass turnover, exudation of organic compounds, and metabolization by soil microbes. Crops bioengineered to increase soil carbon input could boost net CO2 capture and improve agricultural productivity (e.g., via elevated water and nutrient availability). However, genetic engineering targets that control carbon exchange from roots to soil remain poorly defined. Since carbon distribution within plants is controlled by sugar metabolization and transport, genes that alter these processes may also regulate carbon input to root-proximal soil (i.e., the rhizosphere). At Stanford, Christopher will study how these genes affect soil carbon input by Setaria viridis, a model energy grass that is a promising sustainable fuel source. Leveraging high throughput root imaging technology and genetic circuit design, he will construct root-associating bacterial strains and transgenic Setaria that allow researchers to measure/modulate sugar flux from root systems. These living sensors/actuators will be used to determine genetic design rules of soil carbon input at the root-rhizosphere interface. Results will inform engineering of biofertilizer bacteria and functional plant genes that can increase carbon release into soils by other food- and energy-relevant crops.