Susie Dai

My research group is interested in evaluating environmental hazard substances, their interactions with the environment and species, and biological systems that can degrade and detoxify the pollutants. We have established broad analytical platforms to survey a wide spectrum of natural or manmade toxic chemicals such as mycotoxins, microcystins, agricultural, and industrial chemicals. For example, we investigate white rot fungus’s ability to degrade environmental hazardous chemicals like organic compounds. To this end, we apply systems approaches to decipher the important enzyme network that work synergistically to degrade the chemicals. Through genomics and gel-free shotgun proteomics analysis, we discovered the oxidation reduction enzymes such as manganese peroxidase play important roles in both dye decolorization and lignin depolymerization. At the protein function level, we utilize structural dynamics information to guide enzyme engineering to produce more efficient and stable enzymes for bioremediation.  For example, we evaluated xylanase, the enzyme degrades the linear polysaccharide xylan into xylose. By identifying the critical regions in the dynamic interaction between xylan and xylanase, we designed new xylanase with much improved enzyme activity and stability.  We are working on and per- and polyfluoroalkyl substances (PFAS) degradation with fungus and bacteria systems. PFAS, a commonly used manmade stable compound group, has emerged as a major risk for human and environmental health and was found in groundwater, human body and our environment. By identifying the efficient enzymes and suitable environmental conditions, we aim to identify optimal systems to degrade PFAS.

Meanwhile, our laboratory has built a modern analytical tool suite, which includes mass spectrometry-based platforms for monitoring and surveillance, hydrogen-deuterium exchange mass spectrometry for protein structure dynamics analysis, and gel free mass spectrometry-based proteomics analysis. We develop qualitative and quantitative methods for molecular characterizations, protein analysis and proteomics when working in different environmental systems.