First Yeasts to Produce Biobutanol
Biobutanol is one of the bioalcohols considered suitable for use in transport fuels won from plants. Today, the most widely produced bioalcohol is bioethanol, especially in Brazil and the US (the largest producers of ethanol worldwide), and also in Europe, but bioethanol can only be blended up to 10% with normal petrol without it being necessary to modify car engines. A more superior bioalcohol is its big brother, biobutanol. This has a higher energy density which is similar to that of fossil fuel, and is less corrosive, so it can be blended with petrol/diesel in higher concentrations without having to make engine modifications. Due to several challenges hampering the biobutanol production process, it is not yet commercially available.
Yeasts are used for the production of bioethanol, which, as in the production of wine and beer, ferment the sugars contained in plants. Up until now, biobutanol has only been produced in very small amounts using bacteria. The Butalco scientists have successfully genetically modified yeasts to produce biobutanol instead of bioethanol. "Once we have the yeasts producing biobutanol at a quicker rate and achieved higher yields, it will be possible for existing bioethanol production plants to simply exchange the old yeasts with the new Butalco yeasts, and therefore enable an efficient switch to the production of advanced biofuels like biobutanol."
In his presentation, Prof. Boles also mentioned that his research group has successfully constructed yeasts which can make use of sugars in biomass waste feedstock, such as straw and wood processing waste products, or energy crops, such as grasses instead of the valuable sugars in food crops, such as corn. This is important to settle the controversy over biofuels made from food crops. "We are currently linking the use of waste sugars with the production of biobutanol", Boles commented. These yeasts could revolutionise the biofuel market.
BUTALCO develops new production processes for second generation biofuels and biochemicals based on lignocellulose. The core technology based on genetically optimised yeasts enables increased yields in bioethanol production and the production of biobutanol. BUTALCO is currently finalising the technology to use C5/C6 sugars for bioethanol production. Furthermore, BUTALCO is working together with partners to develop an integrated lignocellulose-based bioethanol/biobutanol production process. The development covers the whole process chain including all production steps from lignocellulose hydrolysis to downstream processing.