The Mysterious Transport of Carbon and Bacteria in Soil
Judy Yang, Assistant Professor, Department of Civil, Environmental, and Geo- Engineering, University of Minnesota
Abstract: The transport of carbon and bacteria regulates the biogeochemical cycle of soil carbon and controls the spread of microbial pathogens in soil. The fate of soil carbon is particularly becoming an emergent concern because recent studies observed a burst release of carbon from soil in controlled environments with increasing temperature and/or atmospheric CO2, suggesting that soil may become a carbon source and accelerate climate change. However, these transport processes in soil have remained mysterious, and one major reason is that direct observation of opaque soil is difficult.
In the first part of the talk, I will discuss the new 4D imaging technology we developed that traces the transport of carbon in a microfluidic soil in real time. Using this new technology, we identified the secret interactions among carbon, clay, and bacteria, which control the fate of soil carbon. We proposed a new soil-carbon-bacteria interaction model that can potentially be used to improve our predictions of global carbon cycle. In the second half of the talk, I will discuss a new mechanism for bacteria to spread in soil. Specifically, I discovered that bacteria can self-generate flows in unsaturated porous materials by producing biosurfactants that change the wettability of typical soil surfaces. This new bacterial transport mechanism can potentially be used to improve predictions of soil biogeochemical cycles and the spread of microbial contamination in soil and other similar unsaturated porous materials such as granular materials and tissues. At the end of the talk, I would like to introduce the Environmental Transport (ET) - Lab at SAFL and share my visions about the lab.
About the Speaker: Judy Yang is a new assistant professor in the Department of Civil, Environmental, and Geo-Engineering. She got her master and PhD from the Department of Civil and Environmental Engineering at MIT in 2015 and 2018, respectively. Afterwards, she was a postdoc in the Department of Mechanical Engineering at Princeton University. Judy is interested in problems related to coastal and riverine erosion, the sequestration and release of carbon from soil, and the spread of bacteria in nature. Her lab will focus on developing interdisciplinary approaches to mimic and understand our complex natural environment in the lab. She has been a MIT presidential fellow, MIT Martin Fellow for Sustainability, the founder of a science communication club at MIT (http://trees.mit.edu/ ), and 2018 Caltech young investigator lecturer.