November 5, 2013
UK research reveals biofuel benefits to chickens
A research supported by the Engineering and Physical Sciences Research Council (EPSRC) revealed that chickens could be the unexpected beneficiaries of the growing biofuels industry, feeding on proteins retrieved from the fermenters used to brew bioethanol.
It has long been known that the yeasty broth left over after bioethanol production is nutritious, but it has taken a collaboration between Nottingham Trent University and AB Agri, the agricultural division of Associated British Foods, to prove that Yeast Protein Concentrate (YPC) can be separated from the fibrous cereal matter.
The researchers have also shown that YPC may be a cost-competitive substitute for imported soy-based and similar high-value protein feeds currently used in the diets of chickensbred for meat production.
The project was born out of the vision of biofuels pioneer Pete Williams of AB Agri, who was convinced valuable material was being overlooked when cereals were fermented to make bioethanol.
With Emily Burton of Nottingham Trent University, Wiliams was able to secure funding from the EPSRC for a Cooperation Awards in Science and Engineering (CASE) studentship that allowed them to develop and analyse the process.
To establish the nutritional value of the concentrate, EPSRC CASE student Dawn Scholey examined the composition of the newly isolated, patented YPC in a series of experiments, which showed that it can be readily digested by chickens.
Project supervisor, Burton says the work is only just beginning: "Bioethanol is already a 60-billion-litre per year global market but this project shows the fuel itself is only half the story- immense value lies within other co-product streams too. As well as the proteins, the yeast content provides important vitamins and other micronutrients."
Produced by distilling and fermenting wheat and other agricultural feed stocks, bioethanol has particular potential for use as a petrol substitute. Currently, the dried distiller''s grains with solubles (DDGS) generated as a co-product are sold to the cattle-feed market but this is not big enough to absorb all material that would be generated if bioethanol production ramps up significantly in future.
Burton believes the project helps address an issue often raised in connection with cereal-based biofuels: "One concern with bioethanol is the perception it will compete with food crops for limited farmland. Our new work shows how the two can live side by side."
The new, patented process separates DDGS into three fractions- fibre, watery syrup and YPC, allowing global production of almost three million tonnes of supplementary high-quality protein per annum alongside current levels of bioethanol produced. A project at a US bioethanol facility is now up and running, demonstrating the performance of the process at factory scale.
Every year, 800 million chickens are reared for meat production in the UK and 48 billion worldwide. As well as helping to feed these birds, YPC could partially replace the fish meal used on commercial fish farms.
CASE (Cooperation Awards in Science and Engineering) funding is provided by EPSRC for PhD students working with businesses on research projects of industrial relevance.