From hundreds of compounds identified in the literature as being produced in fungi, 33 terpenes, terpenoids, and polyketides were selected for assessment to identify compounds with potential for liquid transportation fuel applications. Eight of the 33 compounds were identified as having potential as gasoline blend components. Based on predicted boiling points and octane numbers, 2-ethyl-5,5-dimethyl-1,3-cyclopentadiene; sabinene; isobutyric acid; and 1,8-cineole and linalool met the boiling point and octane number requirements used for the assessment, but 2-ethyl-5,5-dimethyl-1,3-cyclopentadiene and isobutyric acid would require some upgrading. Limonene, isoamyl acetate (3-methylbutyl acetate); and 2,2,5,5-tetramethyl-3-hexanone also have gasoline blend potential without upgrading. For diesel fuel, only 3,3,5-trimethyldecane met the boiling point, cetane number, and flashpoint requirements used for the assessment; however, with upgrading, 18 of the 33 compounds evaluated could potentially serve as blend components of diesel fuel. None of the 33 compounds without upgrading met the four ASTM D1655 specifications for Jet A and Jet A-1 fuel, but 3,3,5-trimethyldecane and limonene were very close. With chemical upgrading, 22 of the 33 compounds could have potential as jet fuel blend components. The monoterpene limonene and six sesquiterpenes were identified as fungal-derived compounds that with upgrading could serve as components of high-energy jet, missile, or diesel fuels. The increasing availability of genome sequences enables the identification of important metabolic pathways for hydrocarbon production. The number of fungal-based compounds having potential for use in hydrocarbon fuels and products is increasing as new discoveries through genomics and advances in metabolic engineering are made. Several challenges remain including increasing carbon flux toward hydrocarbon fuel precursors in primary metabolism, increasing the low titers of hydrocarbons produced, and establishing robust host strains.
Revised: December 13, 2017 |
Published: March 1, 2018
Citation
Butcher M.G., P.A. Meyer, R.T. Hallen, K.O. Albrecht, C.K. Clayton, E. Polikarpov, and K.G. Rappe, et al. 2018.Fungal Metabolites as Precursors to Renewable Transportation Fuels.Fuel 215.PNNL-SA-126614.doi:10.1016/j.fuel.2017.10.052