Application of electrodialysis to extract 5′-ribonucleotides from hydrolysate: Efficient decolorization and membrane fouling

In order to simplify the process of extracting 5′-ribonucleotides from hydrolysate in industry in an environmentally friendly manner, electrodialysis was introduced as an alternative route. The feasibility of electrodialysis for the separation of 5′-ribonucleotides from hydrolysate was investigated using a series of membranes under different conditions. The results of the lab-scale experiments indicate that ChemJoy membranes are most suitable for the separation of 5′-ribonucleotides. At a current density of 13.2 A m^-2 or constant voltage of 30 V in batch operation, the yield of 5′-ribonucleotides reaches 97.2% and 95.4%, respectively. Furthermore, the decolorization ratio of 91.6% indicates that most pigments are blocked by the membranes and the current efficiency reaches 70% for guanosine 5′-monophosphate (GMP) production. Remarkably, the 5′-ribonucleotides are 1.3-times more concentrated. Finally, membrane fouling was investigated via SEM and ATR-FTIR, and the TingRun, ChemJoy and Astom cationic membranes showed the same membrane fouling resistance. However, among the anionic membranes, ChemJoy showed the best fouling resistance. The total energy cost of the pilot-scale operation was estimated to be 155.44 $ per t 5′-ribonucleotides. This process integrates preliminary purification, decolorization and concentration, providing a simple, cost-effective and green way to produce 5′-ribonucleotides.