• Research & Development
• Pretreatment
• Enzymes that hydrolyze feedstocks
• Yeast that ferments C5-sugars

Yeast that ferments C5-sugars

The common yeast Saccharomyces cerevisiae is an ideal organism for fermenting sugars into ethanol. This yeast has been used in the fermentation of beer and wine for thousands of years. But this conventional yeast is only capable of fermenting C6 sugars, such as glucose and fructose. C6 sugars are obtained from edible feedstocks: starch from corn or wheat, or sucrose from sugar cane or sugar beet. For second-generation feedstocks, it is absolutely essential that xylose and arabinose are also fermented into ethanol.

The Delft University of Technology, in collaboration with BIRD Engineering, has developed a yeast that is capable of fermenting both xylose and the classical C6 sugars.

Kuyper, M, Toirkens, M.J., Diderich, J.A., Winkler, A.A., Van Dijken, J.P. and Pronk, J.T. (2005).
Evolutionary engineering of mixed-sugar utilization by a xylose-fermenting S. cerevisiae strain.
FEMS Yeast Research 5, 399-409.

Nedalco has applied for a patent to protect the technique described schematically in the figure below. The distinction from the more established method is that xylitol is not an intermediary compound in the route from xylose to xylulose when using Nedalco’s technology.

R&D at Nedalco is working on both the molecular biology and fermentation fronts to obtain yeast suitable for industrial application.