Biomass Group, College of Engineering, Nanjing Agricultural University, 40 Dianjiangtai Road, Nanjing, Jiangsu 210031, China.
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China.
Bioresour Technol. 2024 Feb;394:130237. doi: 10.1016/j.biortech.2023.130237. Epub 2023 Dec 23.
Magnetic biochar was synthesized via chelation of Fe with carboxymethyl cellulose and pyrolysis for covalently immobilizing Eversa® Transform lipase. The magnetic biochar had 75.8 mg/g lipase loading that was 54.1 % higher than that without magnetism. The immobilized lipase achieved 91.3 mg/g lipase loading with 19.2 U/mg lipase activity after optimization. It showed good thermal and acid stability with 82.5 % and 98.2 % relative activity at 45 °C and pH 4, respectively. Its relative activity was 90.8 % after stored for 30 d at 4 °C. After magnetically separated for 10 cycles, it still kept 70.1 % activity due to the strong covalent bonding. The lipase further catalyzed one-pot esterification and transesterification of high acid value oil (38 mg KOH/g) with 95.7 % biodiesel yield and cycled for 10 times at 85.7 % yield. Kinetic study gave the activation energy of 28.7 kJ/mol. The covalently immobilized lipase could find practical applications.
磁性生物炭通过 Fe 与羧甲基纤维素的螯合以及热解来合成，用于共价固定 Eversa® Transform 脂肪酶。磁性生物炭的脂肪酶负载量为 75.8 mg/g，比没有磁性时高 54.1%。经过优化，固定化脂肪酶的脂肪酶负载量达到 91.3 mg/g，脂肪酶活性为 19.2 U/mg。它具有良好的热稳定性和酸稳定性，分别在 45°C 和 pH 4 时具有 82.5%和 98.2%的相对活性。在 4°C 下储存 30 天后，其相对活性为 90.8%。经过 10 次磁分离后，由于强共价键的存在，其仍保持 70.1%的活性。该脂肪酶进一步在高酸值油（38 mg KOH/g）中进行一锅酯化和酯交换反应，得到 95.7%的生物柴油产率，并在 85.7%的产率下循环使用了 10 次。动力学研究得出其活化能为 28.7 kJ/mol。共价固定化脂肪酶具有实际应用的潜力。
