Sustainable design of hollow macroporous chitin carrier with enhanced loading capacity for high-performance lipase bioreactor

A hollow macroporous chitin carrier (HMCC) was developed as a high-efficiency platform for lipase immobilization, offering superior specific surface area, biocompatibility, and protein affinity. Using a NaOH/urea/water treatment system, chitin was dissolved and processed into HMCC, leveraging its amphiphilic properties to achieve remarkable interfacial performance. Compared to the conventional chitin carrier (~0.34 mg/g), HMCC-OA exhibited a highest 3.39-fold increase in protein loading capacity. Immobilization of Geobacillus thermocatenulatus lipase 2 (GTL2) on HMCC-OA yielded a hydrolytic activity of 145.95 U/mg, surpassing free GTL2 by 1.14-fold. In addition, the HMCC demonstrated exceptional versatility by supporting various commercial lipases while showcasing optimal hydrolytic efficiency with GTL2. Notably, GTL2 bioreactor mitigated thermal inactivation at elevated temperatures (up to 90 °C), retained high activity across short- to medium-chain fatty acids (C 4 , C 8 , C 10 ), and maintained significant residual activity (51.79 U/mg) after 10 recycling cycles. These results highlight the innovative design and robust performance of HMCC as a sustainable carrier for lipase bioreactor, enabling enhanced biocatalytic performance demanding thermal stability and interfacial activity.