March 11, 2016
An engineered bacteria may provide a renewable “drop-in” replacement for liquid fuels such as diesel and petrol.
Existing biofuels, such as ethanol, are less energy dense and can also corrode existing infrastructure such as pipelines.
Now scientists at UCLA in California in the USA are developing a next-generation biofuel using proteins found in manure and other animal and human waste and which are more like traditional fossil fuel-based products.
UCLA researcher David Wernick said: “The vast majority of organisms out there don’t consume protein to convert it into a product. They find protein in the environment and then use that to grow. We try to engineer the metabolisms of bacteria so that instead of just growing on this protein they will now take a good portion of it and use it to produce products for us.”
“We’ve engineered bacillus subtilis to do the protein breakdown step and also to convert the resulting material into our product.“ He added: “The products of our process are alcohol biofuels and ammonia. They have more favourable properties as a fuel than ethanol. We try to produce branch chain alcohols that are a little larger, more energy dense and burn more like real gasoline.”
Unlike ethanol, these biofuels are completely compatible with current fuel infrastructure.
Wernick is now hoping to explore the metabolism of the bacteria in more detail to produce higher yields.
Editor’s comment: Engineering bacteria to produce desirable products from waste, such as excreta, not only addresses greenhouse gas production but also a waste disposal challenge – the US alone produces more than 1 billion tonnes of manure – animal and human – annually. Furthermore, engineered bacteria may also be modified to produce other desirable products, such as pharmaceuticals or chemical building blocks.