Production of D -Glucaric Acid with Phosphoglucose Isomerase-Deficient Saccharomyces Cerevisiae

d -Glucaric acid is a potential biobased platform chemical. Previously mainly Escherichia coli, but also the yeast Saccharomyces cerevisiae, and Pichia pastoris, have been engineered for conversion of d -glucose to d -glucaric acid via myo-inositol. One reason for low yields from the yeast strains is the strong flux towards glycolysis. Thus, to decrease the flux of d -glucose to biomass, and to increase d -glucaric acid yield, the four step d -glucaric acid pathway was introduced into a phosphoglucose isomerase deficient (Pgi1p-deficient) Saccharomyces cerevisiae strain. High d -glucose concentrations are toxic to the Pgi1p-deficient strains, so various feeding strategies and use of polymeric substrates were studied. Uniformly labelled 13 C-glucose confirmed conversion of d -glucose to d -glucaric acid. In batch bioreactor cultures with pulsed d -fructose and ethanol provision 1.3 g d -glucaric acid L −1 was produced. The d -glucaric acid titer (0.71 g d -glucaric acid L −1 ) was lower in nitrogen limited conditions, but the yield, 0.23 g d -glucaric acid [g d -glucose consumed] −1 , was among the highest that has so far been reported from yeast. Accumulation of myo-inositol indicated that myo-inositol oxygenase activity was limiting, and that there would be potential to even higher yield. The Pgi1p-deficiency in S. cerevisiae provides an approach that in combination with other reported modifications and bioprocess strategies would promote the development of high yield d -glucaric acid yeast strains.