The fledgling Danish biotech firm Terranol, whose three founders all previously worked for industrial bioproduct giant Danisco, has developed a genetically modified brewer's yeast which it says could enable 30% more biofuel to be produced from biomass, writes professional journal Ingeniøren (The Engineer).
According to Terranol, the improvements in 2nd generation* "cellulosic" bioethanol process efficiency that their new yeast promises, could bring the price of sustainable biofuel where it becomes economically attractive.
Terranol's technological tactic for improving bioethanol yield from biomass involves enabling their yeast strain to ferment pentose** sugars as well as hexose** sugars from plant material into ethanol. This is achieved by introducing a pair of extra genes into brewer's yeast (Saccharomyces cerevisiae) to give it pentose-metabolising ability.
Understandably, Terranol is highly enthusiastic about the potential of their product for 2nd generation bioethanol production, but as Ingeniøren reports, others take a more cautious view. Professor Claus Felby, who specialises in biomass technology at Copenhagen University, commented: "If Terranol successfully develops a yeast strain that can ferment pentose sugars to ethanol on an industrial scale, that would be a major breakthrough. We have seen yeast strains do this in the laboratory, but not in industrial application."
But optimism is in strong supply at Terranol, which is pressing ahead with plans to have a demonstration plant ready by the time the UN Climate Change conference COP15 comes to Denmark in December 2009. The company has commenced collaboration with both Dong Energy and Novozymes, which are respectively making available the process equipment and enzymes for development work to progress.
Last month, the Danish Energy Authority announced that Terranol will receive EUR 1.5m (USD 2.3m) in supportive funding under the Energy Technology Development and Demonstration programme for development of organisms for fermentation of pentose sugars into ethanol.
* 2nd generation (or 2G) signifies bioethanol produced from agricultural waste such as wheat straw, sugar cane bagasse, corn stover and wood chips. 1st generation (or 1G) signifies bioethanol produced from food crops – Ed.
** Plant material contains both cellulose – a biopolymer consisting of the hexose (6-carbon) sugar glucose – and hemi-cellulose, which additionally contains pentose (5-carbon) sugars like xylose and ribose. Ordinary brewer's yeast ferments the hexose sugars to ethanol, but not the pentose sugars – Ed.