BACKGROUND:  As petroleum resources become increasing expensive and renewable resources has been a cause for concern, the search for petroleum substitutes has been increasingly important. Isopropanol is an important alcohol that can be used for biodiesels and bioplastics. Many species of Clostridium have been evaluated for isopropanol production, including several strains of C. beijerinckii. However, the maximum yield of isopropanol has been 30mM maximum concentration. Escherichia coli (E. coli) has been suggested as a better vehicle for metabolic engineering and production. E. coli has been used to produce acetone, but still in limited quantities. There is a need for a better vehicle of isopropanol production, and perhaps E. coli can be used to do so.

INNOVATION:  UCLA researchers have engineered a synthetic pathway into E. coli to produce isopropanol. This is the first time researchers have used E. coli to produce isopropanol, and the amount produced exceeded that from native producers. Researchers assembled the best combination of genes based on the C. beijerinckii pathway to produce acetone through E. coli. Acetone is then converted to isopropanol using acetyl-coenzyme A (acetyl-CoA). Using this engineered strain of E. coli, 81.6 mM of isopropanol has been produced in shake flasks.

POTENTIAL APPLICATIONS 

• Produce high quantities of acetone and isopropanol using a synthetic pathway engineered in E. coli

ADVANTAGES

• High yields of acetone and isopropanol production have been achieved

DEVELOPMENT-TO-DATE:  Investigators have engineered the synthetic pathway in E. coli and have produced a maximum concentration of 148. Mm of acetone.

Related Papers (Selected)

• Hanai T., Atsumi S., Liao J.C. "Engineered Synthetic Pathway for Isopropanol Production in Escherichia coli". Applied and Environmental Microbiology. Dec. 2007 (73:24) 7814-7818 [more]

Reference: UCLA Case No. 2008-177