Katherine Chou's research uses biological systems to maximize production of valuable products (e.g., H2) from renewable waste materials, including plant biomass and greenhouse gases such as carbon dioxide (CO2). Performing targeted functions by genetically engineering non-native biochemical pathways within bacterial strains is integral to Katherine's research.
A main research objective includes understanding the inherent factors constraining a bacterial cell to perform a targeted function. A broad question Katherine strives to answer is how cellular resources in the form of electrons and energy (e.g., adenosine triphosphate) are utilized and limiting. She approaches this question by:
Tracking the carbon flux among the biochemical pathways inside the cells
Developing synthetic biology tools (e.g., riboswitches) to control gene expression in novel microorganisms and enable metabolic control
Elucidating the inherent gene regulatory networks that collectively give rise to a desired phenotype as well as imposing constraints on cellular processes.
Hydrogen (H2) metabolism in thermophilic and anaerobic bacteria
Microbial conversion of lignocellulosic biomass to H2, biofuels, and biochemicals
Adaptive laboratory evolution
Characterization of gene regulatory networks
Developing dynamic control of gene expression for strain engineering of novel microorganisms
One carbon (C1) metabolism
Affiliated Research Programs
Core projects funded by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy (EERE) Fuel Cell Technologies Office:
Microbial conversion of lignocellulosic biomass to H2 as a biofuel; main objectives include improving hydrogen molar yield, rate, and titer from plant biomass using cellulose-degrading bacteria—Clostridium thermocellum—via metabolic engineering.
Coupling rational metabolic pathway engineering and adaptive laboratory evolution to enable a cellulolytic bacterium and consolidated bioprocessing process (CBP) platform organism—Clostridium thermocellum—to co-ferment hemicellulose-derived sugars simultaneously (without carbon catabolite repression).
Understanding cellular mechanisms in conserving electrons and energy (also known as bioenergetics) to maximize H2 production.
Current and past projects funded by NREL Laboratory Directed Research and Development:
High throughput in vitro approach to identifying regulatory targets of transcription factors in bacteria capable of utilizing CO2 or syngas.
Developing inducible and repressible systems to control gene expression and enable real-time metabolic control in thermophiles.
Uncovering C1 metabolism during primarily heterotrophic growth on cellulosic substrate in a thermophilic bacterium—Clostridium thermocellum.
Affiliated research programs of past projects:
EERE Bioenergy Technologies Office, development of a CBP platform organism to produce isoprene.
Office of Science, Basic Energy Science program, "Biological Electron Transfer and Catalysis (BETCy)" Energy Frontier Research Center.
Areas of Expertise
Bacterial physiology and strain development
Metabolic engineering with synthetic biology approaches
H2 metabolism in anaerobic bacteria
Characterization of gene regulatory networks
Ph.D., Chemical and Biomolecular Engineering, University of California, Los Angeles
M.S., Chemical Engineering, University of California, Los Angeles
B.S., Chemical Engineering with Bioengineering Option, University of California, Los Angeles
Staff Scientist, National Renewable Energy Laboratory—Biosciences Center (2013–present)
Postdoctoral Researcher, National Renewable Energy Laboratory—Biosciences Center (2010–2013)
Developing Riboswitch-Mediated Gene Regulatory Controls in Thermophilic Bacteria, ACS Synthetic Biology (2019)
Engineering Cellulolytic Bacterium Clostridium thermocellum to Co-Ferment Cellulose- and Hemicellulose-Derived Sugars Simultaneously, Biotechnology and Bioengineering (2018)
Isotope Assisted Metabolite Analysis Sheds Light on Central Carbon Metabolism of a Model Cellulolytic Bacterium Clostridium thermocellum, Frontiers in Microbiology (2018)
CO2-Fixing One-Carbon Metabolism in a Cellulose-Degrading Bacterium Clostridium thermocellum, Proceedings of the National Academy of Sciences (2016)
Metabolic Engineering of Escherichia coli for 1-Butanol Production, Metabolic Engineering (2008)
Determination of the Escherichia coli S-Nitrosogluathione Response Network using Integrated Biochemical and Systems Analysis, Journal of Biological Chemistry (2008)
Interactions of Nitrosylhemoglobin and Carboxyhemoglobin with Erythrocyte, Nitric Oxide (2008)
Integrated Network Analysis Identifies Nitric Oxide Response Networks and Dihydroxyacid Dehydratase as a Crucial Target in Escherichia coli, Proceedings of the National Academy of Sciences (2007)
Differential Association of Hemoglobin with Proinflammatory High Density Lipoproteins in Atherogenic/Hyperlipidemic Mice. A Novel Biomarker of Atherosclerosis, Journal of Biological Chemistry (2007)
Butanol Production by Recombinant Microorganisms, U.S. Patent No. 20090111154 (2008)