Pathway and protein engineering for improved glucaric acid production in Escherichia coli

Microbial fermentation is an attractive method for the renewable production of chemicals. Glucaric acid was identified as a "top value added chemical from biomass" by the Department of Energy in 2004, and a biological route for its production from glucose in E. coli was developed in our lab in 2009. Two of the pathway enzymes, myo-inositol phosphate synthase (MIPS) and myoinositol oxygenase (MIOX), appear to control flux. This work addressed several limitations of these reactions. One approach was the relief of reactive oxygen species (ROS) to improve MIOX performance. MIOX converts myo-inositol (MI) to glucuronic acid. Overexpression of native catalase and superoxide dismutases led to significantly higher titers of glucuronic acid from MI. This result corresponded to better maintenance of MIOX activity and expression over the course of the fermentation. A reduction in labile iron levels, which are linked to ROS formation, was also shown to improve glucuronic acid titers.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Chemical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Guay, Lisa Marie,Ph. D.Massachusetts Institute of Technology.

Advisor dc:contributor.advisor

• Kristala L. J. Prather.

• Chemical Engineering.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/121776

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/121776