Shayin S. Gottlieb1, Bonny Lieu1, Sydnor T. Withers2, Jay D. Keasling3, and Jack D. Newman1. (1) Amyris, 5980 Horton St Suite 350, Emeryville, CA 94608, (2) Great Lakes Bioenergy Research Center, University of Wisconsin, 3529 Microbial Sciences Building, 1550 Linden Drive, Madison, WI 53706, (3) Joint Bioenergy Institute, 717 Potter Street, Berkeley, CA 94710
Naturally derived isoprenoids are used in neutraceuticals, flavors, fragrances, polymers, drugs and other manufacturing processes. Commercial production of these molecules is often limited by natural resources, sometimes with environmentally deleterious effects. Microbial production of isoprenoids would relieve the supply limitation; however there are relatively few terpene synthases whose function has been well characterized. One isoprenoid of particular interest is the alcohol form of isoprene (isopentenol) which has potential for a wide variety of commercial chemistry applications. Two genes (yhfR and nudF) whose protein products acted directly on prenyl diphosphate precursors and produced isopentenol, were discovered through enrichment of a library of genomic DNA from the isoprene-producing bacterium Bacillus subtilis strain 6051 in E. coli engineered to produce elevated levels of isopentenyl diphosphate and dimethylallyl diphosphate. Expression of yhfR and nudF in E. coli engineered with the mevalonate-based isopentenyl pyrophosphate biosynthetic pathway resulted in the production of isopentenol. Improvements in the mevalonate pathway, including replacement of the original yeast HMG-CoA reductase increased isopentenol titers.
