| abstract |
A mutant Saccharomyces cerevisiae strain utilising xylose as the sole carbon source for fermenting ethanol, characterised by A) expressing xylose isomerase (XI), B) overexpressing xylulokinase (XK), C) overexpressing the pentose phosphate pathway (PPP), and D) non-expressing the endogenous aldose reductase (AR). The overexpression of PPP include simultaneous overexpression of the four non-oxidative PPP enzymes, i.e. ribulose 5-phosphate epimerase (RPE1), ribose 5-phsphate ketol isomerase (RKI1), transaldolase (TAL1) and transketolase (TKL1). The xylose isomerase is derived from a Thermus thermophilus xylA gene. Expression of aldose reductase is lacking by deletion of the GRE3 gene. One strain has been deposited (DSM 15834). |