Increasing ethanol productivity during xylose fermentation by cell recycling of recombinant Saccharomyces cerevisiae.
The influence of cell recycling of xylose-fermenting Saccharomyces cerevisiae TMB3001 was investigated during continuous cultivation on a xylose-glucose mixture. By using cell recycling at the dilution rate ( D) of 0.05 h(-1), the cell-mass concentration could be increased from 2.2 g l(-1) to 22 g l(-1). Consequently, the volumetric ethanol productivity increased ten-fold, from 0.5 g l(-1) h(-1) to 5.35 g l(-1) h(-1). By increasing the biomass concentration, the xylose consumption rate increased from 0.75 g xylose l(-1) h(-1) without recycling to 1.9 g l(-1) h(-1) with recycling. The specific ethanol productivity was in the range of 0.23-0.26 g g(-1) h(-1) with or without cell recycling, showing that an increased cell-mass concentration did not influence the efficiency of the yeast.
Roca
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Center for Process Biotechnology, BioCentrum-DTU, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Olsson
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D000693:Anaerobiosis; D018533:Biomass; D019149:Bioreactors; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D008961:Models, Structural; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D013997:Time Factors; D014994:Xylose / Q000378:metabolism*
D000431:Ethanol; D014994:Xylose; D005947:Glucose