Sugar acids

Several organic acids, e.g. acetic, citric and lactic acids are produced biotechnically in industrial scale. Production processes of novel sugar acids have been developed via efficient new biosynthetic pathways to suitable production hosts. In addition, environmental conditions for high production levels are considered and optimized. The sugar acids can be applied as precursors for polymers.

Some new sugar acids are now being produced at titres and rates relevant for industrial exploitation. Galactaric acid with T. reesei and 2-keto-3-deoxy-L-galactonic acid with A. niger were found suitable for consolidated processes as well D-xylonic and L-arabonic acids were demonstrated with several yeast strains with high tolerance to plant biomass hydrolysate inhibitors. The sugars are applied for precursors for synthesis, novel specialty polymers and modified natural polymers, like cellulose absorbents. The swelling ratios of hydrogels were quite high, up to 1.000 % (10 g of water/g of a hydrogel) and mechanical properties of hydrogels were moderate.