Sustainable biodiesel from an invasive fish using immobilized lipase on magnetic nanogels as a novel management approach

An alternative strategy to mitigate the ecological and economic challenges posed by invasive fish species is to transform these organisms into valuable resources, generating economic benefits while simultaneously addressing ecosystem-related concerns. However, while the search for sustainable feedstocks continues, the specific potential of highly resilient invasive fish species for high-yield biodiesel production has not yet been evaluated. The aim of this study was to address this research gap by producing high-yield biodiesel using the invasive fish Carassius gibelio as an oil source. In this context, lipase immobilized MnFe 2 O 4 - polyhydroxymethyl methacrylate magnetic nanogels were prepared and the production system conditions (lipase amount, methanol/oil molar ratio, and temperature) were optimized. Optimal conditions were obtained using a 4000 U lipase amount, a 5:1 methanol/oil molar ratio and a temperature of 55 °C. A 97.45% biodiesel yield was achieved with this system prepared under optimum conditions, and this prepared biocatalysis system was able to produce biodiesel with at least 50% yield 13 times. This study is the first to use the highly invasive C. gibelio as a sustainable raw material for biodiesel production. It introduces a novel biocatalytic approach by integrating invasive fish species utilization with a reusable MnFe 2 O 4 -pHEMA nanogel system, achieving both high efficiency and operational stability.