Scientists have created a new strain of yeast that radically speeds up the production of ethanol, the biofuel that can be combined with petrol or diesel to make 'gasohol' — a fuel far less polluting than conventional ones.
The strain produced 50 per cent more ethanol over 21 hours than normal yeast, say the team, who publish their research today (8 December) in Science.
Ethanol is made by adding yeast to plant material such as maize, which ferments it. But production is problematic, in part because ethanol is highly toxic to the yeast used for fermentation.
The scientists used a new 'top-down' technique to boost ethanol tolerance, in which they changed one part of the yeast copying mechanism so that multiple genes necessary to achieve ethanol and glucose tolerance were simultaneously altered.
Hal Alper, who led the team, said that because so many genes are involved, engineering high ethanol tolerance via the traditional method of targeting individual genes would have been impossible.
The researchers suggest that using this technique on yeast used for industry could dramatically boost large-scale ethanol production.
Joseph Essandoh Yeddu, a physicist at the Ghana Energy Commission that advises the government on renewable energy, welcomed the results but said their impact on industry would be limited.
Identifying sustainable sources to make ethanol, so that its production does not threaten food supplies, is currently more crucial than increasing the efficiency and speed of ethanol production, he told SciDev.Net.
Reference: Science 314, 5805 (2006)