Preparation of corn-oil as an alternative fuel and transcriptome analysis of metabolic pathway related to fuel component accumulation

Abstract

The direct application of corn-oil as bio-fuel in engines is promising, but the transesterification for plant-oil consumes large energy. This study focused on establishing alternative fuel blends containing corn-oil and low-carbon alcohols (methanol and ethanol), three co-solvents were used to improve the solubility of blends. Also, the transcriptional and genomic analysis was used to investigate the effect of gene expression pattern on the characteristics of corn-oil as a fuel. The result indicated that the blends of corn-oil and low-carbon alcohols could be an alternative fuel by adding co-solvents. Tetrahydrofuran (THF) had the best improvement on the stability of the fuel system, polyoxymethylene dimethyl ethers (PODE) and THF could comprehensively improve the viscosity and density of fuel system, respectively. Furthermore, the component of corn-oil (rich in oleic and linoleic acids) played an important role to enhance fuel solubility and adjust fuel properties. Through the transcriptome analysis of corn seed, fatty acid desaturase 2 (FAD2), stearoyl-ACP desaturase (SAD) and phospholipid:diacylglycerol acyltransferase (PDAT) were the crucial enzymes in the synthesis of unsaturated fatty acids. Meantime, six members of the corn FAD2 (ZmFAD2) gene family were first identified, ZmFAD2-1A and ZmFAD2-1C were highly expressed in three developmental stages of corn, which regulated biosynthesis of unsaturated fatty acids during the seed development. Therefore, corn-oil can be used directly by blending with low-carbon alcohols and co-solvents, meanwhile the transcriptome analysis of the unsaturated fatty acid biosynthesis provides a new idea for the application of corn-oil in engines.