From bin bag waste to jet fuel

Our world runs on fossil fuels. This has been really important for developing our industries, economies and society. But it isn’t a long term, sustainable solution. Fossil fuel stores are running out, and we now know that the emissions from burning fossil fuels are leading to accelerated changes in climate that could be detrimental to all life on earth. At the University of York, we are looking for alternatives to fossil fuels by exploring more renewable carbon sources that can be used as alternatives in the industrial processes that make energy and chemicals. Some examples of renewable biomass sources that are being investigated are agricultural by-products like wheat straw, forestry wastes like wood chips and organic materials in landfill waste .

Landfill or bin bag waste can contain up to 60% organic material, primarily in the form of cardboard, paper, wood and food waste. As part of my PhD project I have been looking for microorganisms that can ferment the organic material in landfill waste and turn it into industrially useful fuels or biochemicals. Basically, I’m trying to turn rubbish into a resource! One microbe I’ve come across is really special – It’s called Rhodococcus opacus . Rhodococcus opacus can convert the carbon from organic landfill waste into molecules called triacylglycerols. The triacylglycerol is accumulated inside the cells and can make up over 50% of their dry weight!

You can see this in the microscopy image which shows Rhodococcus cells that have been stained purple with a dye. The clear regions highlighted by the red arrows contain triacylglycerol. Triacylglycerols are made up of fatty acids that can be converted directly to biodiesel…. or processed further to make sustainable jet fuel! A lot more work needs to be done to get this fermentation from the lab scale to an industrial scale. But, with the combined effort of scientists, engineers and policy makers around the world, biotechnology like this can help us make our industries more sustainable.