471i Effect of Operating Conditions on the Performance of Efficient Succinate-Producing Escherichia Coli Strains

Irene Martinez1, George N. Bennett2, and Ka-Yiu San1. (1) Department of Bioengineering, Rice University, 6100 Main St. MS 142, PO Box 1892, Houston, TX 77005, (2) Biochemistry and Cell Biology, Rice University, 6100 Main st, Houston, TX 77005

Succinate is a valuable industrial chemical that is used in many diverse applications such as food ingredients, in preparing pharmaceuticals, agrochemicals, surfactants, chelators, corrosion inhibitors, foaming agent, perfumery products and it is also precursor of biodegradable polymers and many other organic compounds (Hong and Lee, 2002; Zeikus et al., 1999).

Several metabolic engineered succinate-producing Escherichia coli strains, which achieve close to the maximum theoretical yield, have been constructed and characterized in our lab (Sanchez et al., 2005). However, in addition to the importance of having an efficient strain, many operation factors have been shown to affect the performance of the fermentation process. These include aeration or gas sparging, medium compositions, carbon source and temperature, among others factors. In the present work different operating conditions will be analyzed to asses their effect on the performance of the succinate-producing E. coli strains with respect to succinate yield and productivity.

Hong S. H., Lee S. Y. Importance of redox balance on the production of succinic acid by metabolically engineered Escherichia coli. Appl Microbiol. Biotechnol. 2002, 58(3):286-90.

Zeikus, J. G., Jain M. K., Elankovan, P. Biotechnology of succinic acid production and markets for derived industrial products. Appl. Microbiol. Biotechnol. 1999, 51:545-552.

Sanchez A. M., Bennett G. N., San K.-Y. Novel pathway engineering design of the anaerobic central metabolic pathway in E. coli to increase succinate yield and productivity. Metab. Eng. 2005, 7:229-239.