Separation and purification of N-acetylglucosamine from the fermentation broth of corynebacterium glutamicum by electrodeionisation method

Electrodeionisation (EDI) is a key desalination method that offers superior industrial application prospects for the desalination of bio-based products compared to the electrodialysis and ion chromatography technologies. However, previous studies have scarcely addressed the parameter relationships of this technology in actual fermentation broths or the factors limiting its production. N-acetylglucosamine (GlcNAc) and its derivatives play a significant role in human life and health. Recently, biological fermentation for GlcNAc production has emerged as the preferred method for industrial-scale manufacturing. This study thoroughly examines the application of EDI technology in the desalination of GlcNAc fermentation broth, elucidates the migration behaviour of the target products and salt ions, compares the merits and demerits of existing technologies, and discusses the industrial benefits of EDI. The results suggest that there are optimal values for the resin filling amount, flow rate, and concentration of the fermentation broth during the EDI process. Specifically, the optimal filling amount is 538.8 g per square meter ion exchange membrane, the optimal flow rate is 36 L h⁻¹, and the optimal concentration of the fermentation broth is 150 g L⁻¹. Furthermore, by implementing a comprehensive process involving microfiltration, activated carbon decolourisation, electrodeionisation, and cooling crystallisation, GlcNAc products exceeding 99.5 % purity can be achieved, with an overall yield >75 %. To validate the sustainability of the EDI process, electrode reversal was employed to demonstrate the low-pollution behaviour of the ion-exchange membrane. Additionally, cost comparisons were conducted with the electrodialysis and ion exchange chromatography methods, providing valuable data to support industrial-scale implementation.