Researchers from KIST Clean Energy Research Center are developing a novel microorganism that can produce biodiesel precursors from lignocellulosic biomass. Lignocellulosic biomass is dry plant matter, which includes discarded agricultural by-products, waste paper, cardboard boxes and more.

Conceptual diagram for producing biofuels using microorganisms as raw materials for wood-based biomass. Source: KISTConceptual diagram for producing biofuels using microorganisms as raw materials for wood-based biomass. Source: KIST

Using biodiesel is an effective way to cope with climate change and reduce fine dust emissions. Currently, biodiesel is produced through chemically processing vegetable oil or waste cooking oil. But this is limited because the availability of raw materials is not reliable.

Recently, researchers have been searching for new ways to create biofuels by converting lignocellulosic biomass. The team's new method ultimately doesn’t consume raw materials. Lignocellulosic biomass is an economical and sustainable raw material that can be converted into an eco-friendly fuel using microbial metabolism.

The new microorganism produced a yield that is two times the yield of previous organisms. It produces biodiesel precursors while metabolizing sugars contained in lignocellulosic biomass it eats. The sugar in lignocellulosic biomass is generally composed of 65 to 70% glucose and 35% xylose. The existing, natural microorganisms don’t feed on xylose, which ultimately limits the yield of raw materials. The metabolic pathway of the new microorganism was redesigned with genetic scissors to prevent interference with the supply of coenzymes needed to produce diesel precursors.

Metabolizing xylose was improved by effectively controlling the evolution in the lab by selecting and cultivating only the microorganisms with excellent performance. The team then confirmed that microorganisms could produce the diesel precursors with all the sugar components. The product yield almost doubled when compared to previous studies.

Biodiesel is an effective alternative fuel that can reduce greenhouse gases and fine dust without restricting the operation of existing diesel-fueled vehicles.

A paper on this research was published in Global Change Biology Bioenergy.