CAREER: Engineering Non-Growth Metabolism for High-Yield Biochemical Production

Project: Research project

Project Details


Synthetic biology holds the promise to transform the biosynthesis of drugs, fuels, and chemicals. This promise has not been realized, as poor process economics have proven difficult to overcome for commercialization. Poor economics are a result of cells that divert a significant amount of substrate (e.g., glucose) to cell growth. Routine, non-growth production would remove a major barrier to realizing a thriving biomanufacturing economy by ensuring all substrate would be diverted exclusively to product, without concern for biomass precursors or toxicity to growth. The key challenges to realizing non-growth biosynthesis are two fold: (a) Essential enzymes divert carbon from desired product. Because essential enzymes cannot be genetically deleted, and many can persist for > 30 h after the enzyme’s synthesis has stopped, most gene regulatory approaches are unlikely to succeed in realizing non-growth production. (b) Non-growing cells tend to drastically attenuate metabolism, thereby reducing productivity. Previous genetic approaches (knockout and overexpressions) have had limited success, as the critical phenomena is post-translational (enzyme half life and allosteric regulation). My long-term goal is to deregulate non-growth metabolism to allow biosyntheses of a range of valuable products. The objective of the proposed research is to develop experimental tools to manipulate and characterized non-growth metabolism in E. coli. My central hypothesis is non-growth metabolism must be primarily controlled through post-translational modifications (e.g., inducing protein instability and manipulating allosteric regulation) rather than control of RNA and protein synthesis (Scientific Rationale). We have demonstrated a novel cellular engineering tool that allows rapid, inducible degradation of metabolic enzymes, and enables a novel approach to testing my hypothesis (Preliminary Data). The impact of the proposed work would be a new engineering paradigm that enables near-perfect biocatalyst with process economics that are impossible in most growth-coupled processes. My experience in metabolic engineering, protein engineering, and metabolic network modeling offers a unique skillset to engineer proteins and manipulate metabolic networks (PI Biosketch). As well, my connections with Manus Biosynthesis and DuPont will facilitate industrial application of the work. I will test my central hypothesis and accomplish the overall goals by developing novel tools to knockdown essential enzymes and systematically engineering flux regulation for two types of product pathways: ATP generating and ATP consuming.
Effective start/end date3/1/152/28/21


  • National Science Foundation (CBET-1452549-003)


Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.