• Home
  • Search Results
  • Toward production of jet fuel functionality in oilseeds: identification of FatB acyl-acyl carrier protein thioesterases and evaluation of combinatorial expression strategies in Camelina seeds.

Toward production of jet fuel functionality in oilseeds: identification of FatB acyl-acyl carrier protein thioesterases and evaluation of combinatorial expression strategies in Camelina seeds.

Journal of experimental botany (2015-05-15)
Hae Jin Kim, Jillian E Silva, Hieu Sy Vu, Keithanne Mockaitis, Jeong-Won Nam, Edgar B Cahoon
ABSTRACT

Seeds of members of the genus Cuphea accumulate medium-chain fatty acids (MCFAs; 8:0-14:0). MCFA- and palmitic acid- (16:0) rich vegetable oils have received attention for jet fuel production, given their similarity in chain length to Jet A fuel hydrocarbons. Studies were conducted to test genes, including those from Cuphea, for their ability to confer jet fuel-type fatty acid accumulation in seed oil of the emerging biofuel crop Camelina sativa. Transcriptomes from Cuphea viscosissima and Cuphea pulcherrima developing seeds that accumulate >90% of C8 and C10 fatty acids revealed three FatB cDNAs (CpuFatB3, CvFatB1, and CpuFatB4) expressed predominantly in seeds and structurally divergent from typical FatB thioesterases that release 16:0 from acyl carrier protein (ACP). Expression of CpuFatB3 and CvFatB1 resulted in Camelina oil with capric acid (10:0), and CpuFatB4 expression conferred myristic acid (14:0) production and increased 16:0. Co-expression of combinations of previously characterized Cuphea and California bay FatBs produced Camelina oils with mixtures of C8-C16 fatty acids, but amounts of each fatty acid were less than obtained by expression of individual FatB cDNAs. Increases in lauric acid (12:0) and 14:0, but not 10:0, in Camelina oil and at the sn-2 position of triacylglycerols resulted from inclusion of a coconut lysophosphatidic acid acyltransferase specialized for MCFAs. RNA interference (RNAi) suppression of Camelina β-ketoacyl-ACP synthase II, however, reduced 12:0 in seeds expressing a 12:0-ACP-specific FatB. Camelina lines presented here provide platforms for additional metabolic engineering targeting fatty acid synthase and specialized acyltransferases for achieving oils with high levels of jet fuel-type fatty acids.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
Toluene, anhydrous, 99.8%
Sigma-Aldrich
Sulfuric acid, 99.999%
Sigma-Aldrich
Heptane, anhydrous, 99%
Sigma-Aldrich
Lithium chloride, for molecular biology, ≥99%
Sigma-Aldrich
Lithium chloride, powder, ≥99.98% trace metals basis
Sigma-Aldrich
Lithium chloride solution, 8 M, for molecular biology, ≥99%
Sigma-Aldrich
Lithium chloride, BioXtra, ≥99.0% (titration)
Sigma-Aldrich
Lithium chloride solution, 0.5 M in anhydrous tetrahydrofuran
Sigma-Aldrich
Lithium chloride, BioUltra, for molecular biology, anhydrous, ≥99.0% (AT)
Supelco
Methanol solution, contains 0.10 % (v/v) formic acid, UHPLC, suitable for mass spectrometry (MS), ≥99.5%
Supelco
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
Lithium chloride, AnhydroBeads, −10 mesh, 99.998% trace metals basis
Sigma-Aldrich
Lithium chloride, AnhydroBeads, −10 mesh, ≥99.9% trace metals basis
Sigma-Aldrich
Methanol, NMR reference standard
Sigma-Aldrich
Lithium-7Li chloride, 99 atom % 7Li, 99% (CP)
Sigma-Aldrich
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 3 mm × 8 in.
Sigma-Aldrich
Methanol-12C, 99.95 atom % 12C