Ko_2025_Bioresour.Technol_435_132941

The disposal of animal rendering waste oil presents substantial environmental challenges, highlighting the need for efficient and sustainable repurposing strategies. This study reports a pioneering enzymatic approach for converting animal rendering waste oil into biodiesel, representing the first reported application of this method. Furthermore, this is the first study to use ordered, structured large-pore mesoporous silica derived from rice husks (OLMS-RH) as an enzyme support, with a ship-in-a-bottle strategy to increase the enzyme stability, reusability, and catalytic efficiency. The immobilized lipase (LP@OLMS-RH) exhibited a 3.91-fold increase in specific activity and marked thermal and pH stability, and retained its performance for nine reaction cycles and 100 days of storage. Under optimized conditions, LP@OLMS-RH achieved a maximum biodiesel yield of 97.0 % within 7 h, significantly surpassing the 61.7 % yield obtained using free lipase. These enhancements were attributed to hyperactivation of the immobilized enzyme, improved substrate accessibility, and tailored microenvironment provided by the OLMS-RH. This study established OLMS-RH as a highly effective enzyme immobilization platform, enabling the development of a durable and reusable catalytic system for biodiesel production. This approach offers a scalable and environmentally sustainable solution to global waste management challenges by simultaneously improving enzyme performance and facilitating waste oil recycling.