DESYRE · Designed yeast for renewable bioethanol production
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2007-02-01 → 2009-01-31
- EU contribution
- €157,449
- Participants
- 1
- Scheme
- EIF
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Results in brief
Final Activity Report Summary - DESYRE (Designed yeast for renewable bioethanol production)
Lignocellulosic biomass, such as sustainable forestry and agricultural waste, contains large amounts of energy, stored in the form of sugars polymers such as cellulose and hemicellulose. Cellulose is composed of glucose, while hemicellulose is a polymer of different sugars, such as mannose, galactose, xylose and arabinose. Sugars can be converted to liquid biofuels, such as bioethanol, via fermentation. Bakers' yeast (Saccharomyces cerevisiae) is the prime choice for the production of bioethanol, since it converts most sugars to ethanol with high yield and productivity. However, yeast is unable to utilise xylose and arabinose, which account for a significant portion of lignocellulosic material. Thus, the objective of the work performed was to design new S. cerevisiae strains able to produce ethanol not only from the easily fermentable sugar glucose, but also from xylose and arabinose. Through metabolic engineering, new yeast strains were generated. The newly generated strains displayed different combinations of enzymes, forming the pathways through which xylose and arabinose could be introduced in yeast's metabolism and converted to ethanol. The strains were characterised in well-controlled bioreactors, so that the fermentation performance of each strain carrying different combination of enzymes could be thoroughly compared. In addition, new mutant enzymes, with improved characteristics for the expression in S. cerevisiae were tested. Finally, a combination of enzymes, encoded by genes from different organisms belonging to the kingdom of 'fungi' proved to be a promising solution for the development of new pentose fermenting strains.
Data: CORDIS, © European Union
Project objective
The objective of the proposed research is to design efficient yeast strains to be used for the production of bioethanol from renewable resources. Bioethanol from lignocellulosics is a friendly alternative to fossil fuels that could significantly reduce net atmospheric CO2 emission and contribute to the geopolitical objective of reducing energy imports.However, the production cost of bioethanol from various raw materials must be reduced to become an economically feasible alternative. This includes the design of yeast strains that are able to utilise the pentoses xylose and arabinose, that represent a significant amount of lignocellulosic sugars, for the fermentation to ethanol.The research project proposes to combine the most successful strategies for xylose and arabinose utilisation in an industrial Saccharomyces cerevisiae strain, for further use in bioethanol pilot plants.Various combinations of xylose and arabinose pathways that were each independently evaluated in yeast will be introduced in one of the best industrial yeast that is currently available for the fermentation of lignocellulosics. The newly developed strains will be thoroughly physiologically characterised for mixed sugar fermentations using well-controlled bioreactors.A metabolic flux mode l including arabinose and xylose pathways will be designed and used to quantify intracellular fluxes in order to decipher the interactions resulting from simultaneous conversion of both pentoses. The strain development will be performed in collaboration with chemical engineers, in order to satisfy the criteria of real fermentation conditions.Finally, the most promising strains will be tested in larger scale, at the Swedish pilot plant situated in ornskoldsvik. The host has leading researchers in the fields covered and will provide a well-focused programme of specialist and complementary skills training. The training programme will promote a holistic S and T approach to solving industrial problems.
Original text from CORDIS.
Participants
- LUNDS UNIVERSITET · LUNDCoordinatorSweden
Links
Data: CORDIS, © European Union