Chitosan oligosaccharides (COS) are bioactive compounds with promising applications in functional foods, but their enzymatic production is hindered by high costs and operational instability. To address this, we developed a food-compliant magnetic bimodal mesoporous silica (Fe3O4@BMS) biocatalyst for sustainable COS synthesis via cellulase immobilization. The hierarchically structured carrier combined small (2-5 nm) and large (20-40 nm) mesopores, offering a large surface area of 851 m2/g. The immobilized cellulase demonstrated superior stability, maintaining 83.60 ± 3.32% residual activity at 80 °C, alongside exceptional pH adaptability (3-9). Magnetic Fe3O4 integration facilitated rapid biocatalyst recovery, retaining about 70% of catalytic efficiency after 10 repeated cycles. In a scaled-up stirred-tank reactor, the system achieved a high yield of 316.33 ± 9.39 mg/g reducing sugar from chitosan after 5 h under optimized conditions. This work offers an industrially scalable route for COS production, aligning with green chemistry and food safety standards.
Zhu et al. (2026) studied this question.