Supercharging Bacterial Biofuel Production

Researchers in South Korea have developed a new strategy to efficiently produce fatty acids and biofuels from glucose.

In a study published in Nature Chemical Biology, researchers from Korea Advanced Institute of Science and Technology (KAIST) report the development of engineered microorganisms that can produce record-breaking amounts of fatty acids.

Sustainable bio-based energy sources such as biodiesel are urgently needed to replace fossil fuels. Currently, biodiesel is produced through the transesterification of vegetable oils or animal fats. However, the use of agricultural products for the production of biofuels reduces the amount of arable land available for food production.

Working with engineered Escherichia coli bacteria, a team led by KAIST Distinguished Professor Lee Sang Yup has previously produced short-chain hydrocarbons that can be used as gasoline. However, their production efficiency of 0.58 g/L fell short of the levels required for commercialization.

In the present study, Lee and his team used a different strain—Rhodococcus opacus—to produce fatty acids from glucose, one of the most abundant and cheap sugars derived from non-edible biomass.

First, the team optimized the cultivation conditions of R. opacus to maximize the accumulation of oil, which serves as a precursor for the biosynthesis of fatty acids and their derivatives. Then, they systematically analyzed the metabolism of the strain and redesigned it to accumulate higher levels of fatty acids and allow fatty acid ethyl esters and long-chain hydrocarbons to be produced.

They found that the resulting strains produced 50.2, 21.3, and 5.2 g/L of fatty acids, fatty acid ethyl esters and long-chain hydrocarbons, respectively. These are all the highest concentrations ever reported by microbial fermentations.

“This technology creates fatty acids and biodiesel with high efficiency by utilizing lignocellulose, one of the most abundant resources on the Earth, without depending on fossil fuels and vegetable or animal oils. This will provide new opportunities for oil and petroleum industries, which have long relied on fossil fuels, to turn to sustainable and eco-friendly biotechnologies,” said Lee.

Originally published in Asian Scientist Magazine. Read original article here.

 

To know more about the study, download the full journal article at Nature Chemical Biology.