The synthesis of the diverse and very complex structured HMOs is hardly accessible by chemical ways but facilitated by regioselective enzymes. Hence, c-LEcta with its key technologies in enzyme engineering and Glycom with its expertise in the development and commercialization of HMOs, established a highly efficient process for the enzymatic production of these specific oligosaccarides in a collaboration project. Applying c-LEcta’s proprietary patent-protected enzyme engineering platform, enzymes were developed to catalyze the transfer of carbohydrates between compounds for high yields in the complex target structures. Native enzyme activities were modified to improve the ratio of synthesis to hydrolysis by the factor of 10.000: Hydrolases were evolved to become transferases. These processes were recently presented at several international conferences, such as Gordon Research Conference on Biocatalysis, Biddeford, USA and the International Carbohydrate Symposium, New Orleans, USA.