A sustainable biotechnological process for the efficient synthesis of kojibiose

Abstract

This work reports the optimization of a cost-effective and scalable process for the enzymatic synthesis of kojibiose (2-O-α-D-glucopyranosyl-α-D-glucose) from readily available and low-cost substrates such as sucrose and lactose. This biotechnological process is based on the dextransucrase-catalysed initial synthesis of a galactosyl-derivative of kojibiose (4-O-β-D-galactopyranosyl-kojibiose) followed by the removal of residual monosaccharides using a Saccharomyces cerevisiae yeast treatment, and a thorough hydrolysis step with Kluyveromyces lactis β-galactosidase. Depending on the final purification stage, i.e. extension of the yeast treatment or the use of preparative liquid chromatography, the purity of the produced kojibiose ranged from 65% to ≥99%, respectively. The moderately high yield achieved (38%, in weight respect to the initial amount of lactose) using this affordable synthesis process could expand the potential applications of kojibiose according to the bioactive properties that have been associated with this disaccharide, so far limited by its low availability.