Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Panagiotis Sarantinopoulos1, Aldo Greeve
1, Maurice Toirkens
1, Bianca Gielesen
1, Denise van Suylekom
1, Michel Berkhout
1, Aloys Teunissen
2, Inge Minneboo
2 and Paul Klaassen
1, (1)DSM Biotechnology Center, Delft, Netherlands, (2)C5 Yeast Company, Bergen op Zoom, Netherlands
In the past decades it has become clear that for sustainable and cost-effective production of fuel ethanol the lignocellulosic fractions of plant biomass should be used. As a result, lignocellulosic feedstocks are considered to be of great economic and environmental significance for biotechnological production processes. Economically efficient ethanol production requires not only glucose consumption, but also xylose and arabinose conversion at high rates and yields.
Saccharomyces cerevisiae is presently the organism of choice for industrial ethanol production. Although wild-type
S. cerevisiae strains ferment hexoses with high efficiency, they cannot grow on or use pentoses.
DSM has developed an industrial advanced yeast strain that has been genetically engineered to enable the conversion of the pentose sugars xylose and arabinose at high yield to ethanol, retaining at the same time the ability to ferment rapidly hexoses. The excellent performance of this strain has been illustrated on lab- and pilot-scale in lignocellulosic hydrolysates at an economically relevant dry matter level.
This paper describes the work aimed at improving further the C5-sugars conversion rates by this engineered strain. For this purpose, evolutionary engineering strategies were followed, such as sequential batch reactor (SBR) and chemostat cultivations. The fermentation kinetics of C6- and C5-sugars in synthetic media as well as in lignocellulosic hydrolysates will be presented.
