Sunday, May 3, 2009
1-08
Progress toward a Renewable, Plant-Based Production System for Methacrylate
Joon-Hyun Park1, Elena Doukhanina1, Andrew Park1, Amr Ragab1, Liping Zhang1, Ryan Miller1, Douglas Hawkins2, Steven Thomas1, and Steven Bobzin1. (1) Ceres, Inc, 1535 Rancho Conejo Blvd., Thousand Oaks, CA 91320, (2) Rohm and Haas Chemicals LLC
The objective of this DOE-funded research program is to utilize the metabolic pathways that already exist in plants to genetically engineer methacrylate production into a cellulosic ethanol biomass crop, such as switchgrass. Methacrylate could provide a value-added co-product for biomass conversion processes. While methacrylate is a relatively rare metabolite in biological systems, it does appear as an intermediate in primary and secondary metabolic pathways with high carbon flux, namely amino acids and terpenes. To utilize the existing metabolic capacity of plants to produce high yields of chemicals that can be readily converted to methyl methacrylate, we are focusing on the branched chain amino acid degradation pathway. Methacrylate and a number of closely related chemicals are produced as free acids and thioesters of coenzyme A in the catabolic pathway of the branched chain amino acid (BCAA), valine. Under normal conditions, methacrylate and related intermediates do not accumulate to measurable levels because of the catabolic efficiency of the pathway, which is focused on redistributing carbon from the BCAA pool into the TCA cycle. In this presentation, we will discuss the manipulation of BCAA catabolic intermediates in Arabidopsis transgenic lines carrying over-expression constructs of pathway genes and/or T-DNA knock-out lines of them.
This work is funded under DOE/USDA: DE-PS36-06GO96002F