(143d) Tools for Engineering Non-Growth Metabolism

Authors: 
Tyo, K. E. J., Northwestern University
Greene, J., Northwestern University
Bothfeld, W., Northwestern University
Brotz, M., Northwestern University
Broadbelt, L. J., Northwestern University

Stationary phase metabolism that is not carbon-limited is ideal for metabolic engineering.  Without cell growth, feedstocks can be efficiently converted to product and toxicity that leads to growth-inhibition is irrelevant.  However, to date, most metabolic engineering tools have focused on engineering growing cells, with only modest effort being applied to non-growing cells.  While there is great promise, non-growth metabolic engineering presents new challenges, as post-translational (e.g., allosteric) enzyme regulation dominates control and is not amenable to analysis by transcriptomics/proteomics or engineering by altering promoters.

Our lab is developing a suite of tools to engineer non-growth metabolism in E. coli.  I will discuss computational and experimental efforts to understand, predict, and control non-growth metabolic regulation for optimal biosynthesis.  We are developing non-growth metabolic models that accurately reproduce different non-growth conditions and predict metabolic perturbations.  These models are complemented by experimental strategies to uncover and overcome condition-specific metabolic regulation.  Finally, we are developing next-gen synthetic biology circuits to manage the transition to non-growth and optimize product synthesis.  This work should be applicable to a broad range of products and substantially improve process economics by improving titers, yields, and productivity.

Our strategy of model-driven metabolic engineering is deeply rooted in the training experience and research approach from my time in the Stephanopoulos lab.  It is an honor to be mentored by Greg, and a pleasure to honor his achievements.