Fuel from cardboard waste

The current method of producing biodiesel by chemically processing vegetable oil or waste cooking oil, such as palm or soybean oil, is limited because of the unreliable availability of raw materials. Therefore, there is an effort to develop biofuels by converting lignocellulosic biomass generated as a by-product of farming or logging, instead of consuming raw materials derived from food crops.

Dr Sun-Mi Lee and her team at the Clean Energy Research Center of the Korea Institute of Science and Technology (KIST) have now developed a novel microorganism capable of producing biodiesel precursors from lignocellulosic biomass such as discarded agricultural by-products, waste paper and cardboard boxes. This microorganism has achieved a product yield twice of what was obtainable from its predecessors.

The novel microorganism can produce biodiesel precursors during the process of metabolising sugars contained in the lignocellulosic biomass that it feeds on. The sugar contained in lignocellulosic biomass is generally composed of 65–70% glucose and 30–35% xylose. While microorganisms that exist in nature are effective in producing diesel precursors by metabolising glucose, they do not feed on xylose, thus limiting the yield of the raw materials.

To solve this problem, the KIST research team developed a new microorganism that can produce diesel precursors by effectively metabolising xylose as well as glucose. In particular, the metabolic pathway of the microorganism was redesigned using genetic scissors to prevent interference with the supply of coenzymes essential for producing diesel precursors.

Image credit: ©stock.adobe.com/au/Vlad Chorniy