Development of a magnetic responsive biocatalalytic membrane reactor (MR-BMR) to produce galacto-oligosaccharides (GOS) using saturated lactose concentrations

This study aimed to enhance biocatalytic efficiency and tackle the challenges of enzyme deactivation and membrane fouling in membrane bioreactors used for synthesizing galacto-oligosaccharides (GOS) from highly concentrated lactose solutions. To this end, a magnetic responsive biocatalytic membrane reactor (MR-BMR) employing immobilized Aspergillus oryzae β-galactosidase on iron oxide super-paramagnetic beads was developed. The MR-BMR system showed significant improvements in biocatalytic efficiency compared to the membrane bioreactor using soluble enzymes. Notably, the polyvinylidene fluoride membrane achieved a critical flux of 24.26 kg/m²/h at 55°C and 1.7 bar, ensuring superior operational stability. Although enzyme immobilization reduced the GOS yield from 25% to 10%, the system maintained consistent performance over 12 repeated batches, effectively doubling the specific productivity and flux, and maintaining a stabilization factor of 32. These findings highlight the MR-BMR's potential to markedly enhance the sustainability of GOS production by facilitating the biocatalyst's easy recovery and reuse, thereby promoting higher throughput in biocatalytic applications. This innovation aligns with the objectives of advanced conversion technologies and integrated biorefineries, setting a new standard for bioprocess efficiency.