A sustainable biotechnological process for the efficient synthesis of kojibiose

10 This work reports the optimization of a cost-effective and scalable process for 11 the enzymatic synthesis of kojibiose (2-O-α-D-glucopyranosyl-α-D-glucose) from 12 readily available and low-cost substrates such as sucrose and lactose. This 13 biotechnological process is based on the dextransucrase-catalysed initial synthesis of a 14 galactosyl-derivative of kojibiose (4-O-β-D-galactopyranosyl-kojibiose) followed by 15 the removal of residual monosaccharides by using a Saccharomyces cerevisiae yeast 16 treatment, and a thorough hydrolysis step with Kluyveromyces lactis -galactosidase. 17 Depending on the final purification stage, i.e. extension of the yeast treatment or use of 18 preparative liquid chromatography, the purity of the produced kojibiose ranged from 19 65% to ≥ 99%, respectively. The moderately high-yield achieved (38%, in weight 20 respect to the initial amount of lactose) using this affordable synthesis process could 21 expand the potential applications of kojibiose according to the bioactive properties that 22 have been associated to this disaccharide, so far limited by its low availability. 23 24