Department of Chemical Engineering
Massachusetts Institute of Technology
77 Massachusetts Ave.
Cambridge, MA 02139 USA
Phone: (617) 258-8037
M.S. Chemical Engineering Practice
Massachusetts Institute of Technology (2011)
B.S. Chemical Engineering
University of California, Berkeley (2008)
Strategies for the Improvement of D-Glucaric Acid Production in E. coli
D-glucaric acid is a naturally occurring compound which has been explored for a myriad of potential uses, including biopolymer production and cancer treatment.
Several additional uses for D-glucaric acid were identified in 2004, when the U.S. Department of Energy named the compound as a “top value-added chemical from biomass”
(Werpy and Petersen, 2004). In the Prather Lab, we have constructed a biosynthetic route to produce D-glucaric acid from glucose in E. coli consisting of three heterologous
enzymes (Figure, below), yielding D-glucaric acid titers of 1.17 g/L from a 10 g/L glucose feed (Moon et al., 2009). Analysis of the pathway revealed the second
heterologous enzyme in this pathway, myo-inositol oxygenase (MIOX), which catalyzes the conversion of myo-inositol to D-glucuronic acid, to be limiting. Soluble expression of MIOX
is also much lower than that of the other two heterologous enzymes. In addition, it was observed that the presence of myo-inositol, the substrate for MIOX, to the culture medium resulted
in significantly higher MIOX activity.
My research focuses on the development and application of strategies towards the improvement D-glucaric acid production in E. coli. These strategies may be classified broadly into two groups:
- Metabolic Engineering
The field of metabolic engineering focuses on improving the titers, productivity, and/or selectivity of a product of interest via control of cellular metabolism
and heterologous pathway flux. A wide variety of strategies are employed to maximize flux through a desired pathway while minimizing the burden imposed by expression of
heterologous genes. Such strategies include deletion of off-pathway reactions which siphon flux away from the desired product, overexpression of pathway genes, protein
engineering for increased activity, and removal of regulatory mechanisms which may limit pathway flux. Given that MIOX
- Synthetic Biology
Moon, T.S., Yoon, S.H., Lanza, A.M., Roy-Mayhew, J.D., Prather, K.L.J. “Production of glucaric acid from a synthetic pathway in recombinant Escherichia coli.” Applied and Environmental Microbiology 75:589-595. (2009)
Moon, T.S., Dueber, J.E., Shiue, E., and Prather, K.L.J. “Use of modular, synthetic scaffolds for improved production of glucaric acid in engineering E. coli.” Metabolic Engineering 12(3);289-305. (2010)
Shiue, E. and Prather, K.L.J. “Synthetic biology devices as tools for metabolic engineering.” Biochemical Engineering Journal. 65:82-59. (2012)
Werpy, T. and Petersen, G. “Top Value Added Chemicals from Biomass, Volume I.” (2004)
Shiue, E. and Prather, K.L.J. “Improving D-glucaric acid production from myo-inositol in E. coli by increasing MIOX stability and myo-insotiol transport.” Metabolic Engineering. 22:22-31 (2014).
Shiue, E. and Prather, K.L.J. “Synthetic biology devices as tools for metabolic engineering.” Biochemical Engineering Journal. 65:82-89. (2012)
Moon, T.S., Dueber, J.E., Shiue, E., and Prather, K.L.J. “Use of modular, synthetic scaffolds for improved production of glucaric acid in engineered E. coli.” Metabolic Engineering. 12(3):298-305. (2010)