A research team led by Distinguished Professor Sang Yup Lee developed microbial strains that efficiently transform glucose into fatty acids and biofuels. This work laid a foundation for the sustainable production of a wide range of fatty acid-based products from renewable carbon sources.
Fossil fuels, which have long been energy resources for our daily lives, have caused serious challenges, including depletion of their reserves and their role in global warming. Sustainable production of renewable energy has emerged as an essential alternative, and many studies to replace fossil fuels are currently underway. One of the representative examples is biodiesel. Currently, biodiesel is mainly being produced through transesterification of vegetable oils or animal fats.
The research team previously developed Escherichia coli strains that produce short-chain hydrocarbons, which can be used as gasoline (published in Nature as a cover paper in 2013). However, the production efficiency of the short-chain hydrocarbons using E. coli (0.58 g/L) fell short of the levels required for commercialization.
To overcome this challenge, the research team employed oil-accumulating Rhodococcus opacus as a production host in this study. First, the team optimized the cultivation conditions of R. opacus to maximize the accumulation of oil (triacylglycerols), which serves as a precursor for the biosynthesis of fatty acids and their derivatives. They subsequently redesigned metabolism of R. opacus to further improve the production levels of fatty acids and fatty acid-derived biodiesels, i.e., fatty acid ethyl esters and long-chain hydrocarbons. The resulting R. opacus strains produced 50.2, 21.3, and 5.2 g/L of fatty acids, fatty acid ethyl esters, and long-chain hydrocarbons, respectively. These concentration values are the highest ones ever reported via microbial fermentations. These strains are expected to contribute to the industrialization of microbial biodiesel production.
This work titled "Engineering of an oleaginous bacterium for the production of fatty acids and fuels" was published in Nature Chemical Biology on June 17, 2019.
