Combining the Power of Biocatalysis and Membrane-Based Purification To Access NADP⁺

In this study, using a model solution corresponding to the final medium composition of the NADP⁺ enzymatic production, we present for the first time a sustainable and simple alternative membrane-based filtration process that readily provides NADP⁺ in high purity. A membrane selection was first performed, and the GE membrane (Suez Water Technologies & Solutions (USA)) was shown to provide the best NADP⁺ retention rate >80% at 4 bar. An enzymatic strategy based on the addition of a commercial ATP diphosphohydrolase (apyrase from potatoes) to the model solution significantly simplified the composition of the medium, resulting in a very good discrimination profile between NADP⁺ and AMP retention (69.3% gap) on the one side, and NADP⁺ and adenine (87.5% gap) on the other. These data allowed to predict a profile of purity and loss of NADP⁺ as a function of diafiltration volume (DV). According to these predictions, a >90% purity could be achieved after only 4 DV, demonstrating that this membrane-based purification method achieves a very high purity rate of NADP⁺ while being competitive compared to the other conventional methods currently used.