Turning bad smells into good ones!

Enabled by funding from IBioIC’s Feasibility Fund, the waste-based biodiesel manufacturer, Argent Energy, have undertaken a project with researchers at the University of Edinburgh which has resulted in several positive outcomes including funding from BBSRC for a four-year PhD project to advance the project’s investigations with a view to commercial application.

The project investigated the feasibility of transforming waste oils into compounds relevant to the fragrance and flavours industry.

Combining Argent Energy’s expertise in processing and recycling waste fats and oils for biodiesel production, and the Wallace lab’s expertise in transforming compounds using a novel green chemistry and biological approaches, the project aimed to transform waste oleic acid into higher value chemicals.

What is oleic acid and why is it a problem?

Oleic acid is a naturally occurring unsaturated fatty acid found in a large number of oils, including olive, peanut, sunflower and sesame oils. The high abundance of oleic acid in foodstuffs, although good for human health, has a significant impact on UK food-derived waste streams and sewage systems. Fatbergs are composed of fats and oils, which form around inorganic waste in sewers. As fatbergs build-up, they can reach massive sizes (some are over 250m long!) and cause blockages. As the name suggests, these fatbergs contain huge amounts of fatty acids, the most abundant being oleic acid, which can be used as a renewable feedstock.

Recycling oleic acid to value-added compounds

Oleic acid is a precursor to a plethora of industrially relevant compounds that have traditionally relied upon petro-chemically derived starting materials. Difficulties in switching to this more environmentally friendly precursor lies in the limited number of enzymes that are actually able to breakdown oleic acid before transformation to other compounds.

The Wallace Lab made a strong start to this very challenging project by identifying transformation routes and specific enzymes that could work alongside a green chemical catalyst to degrade and transform oleic acid into an intermediary compound. Additionally, Argent provided waste oils for toxicity and reactivity testing.

This preliminary work has set a strong foundation opening up a number of possible routes for this ambitious strategy. One of the challenges identified during the project was the ability of the bacteria to express the chosen enzyme in the correct form and at high enough levels for utilisation.

Funding for a 4-year PhD project has been secured from BBSRC to continue to investigate this novel approach to deal with waste oils in an environmentally friendly and industrially relevant way.