Inulin fructotransferase(IFTase),a microbial enzyme,efficiently catalyzes the conversion of inulin into difruc-tose anhydrideⅢ(DFAⅢ).However,the poor stability and reusability of IFTase limits its industrial applica...Inulin fructotransferase(IFTase),a microbial enzyme,efficiently catalyzes the conversion of inulin into difruc-tose anhydrideⅢ(DFAⅢ).However,the poor stability and reusability of IFTase limits its industrial application.To overcome this challenge,IFTase from Paenarthrobacter aurescens QL1.001 was immobilized in calcium algi-nate microcapsules using the method of emulsification/internal gelation in this work.A systematic optimization of the microcapsule preparation parameters was conducted using a single-factor experimental design,resulting in an optimal formulation:1.5%sodium alginate concentration,a molar ratio of calcium carbonate to sodium alginate(Ca/Alg)of 0.33,a molar ratio of glacial acetic acid to calcium carbonate(acid/Ca)of 5,the enzyme amount of 4 mg,and ferroferric oxide(Fe_(3)O_(4))amount of 10 mg.Furthermore,the particle size of the micro-capsules was regulated via adjusting the stirring speed,revealing that as the stirring speed increased,the particle size decreased gradually,while the recovery of immobilized enzyme remained relatively stable.Compared to the free enzyme,IFTase immobilized within calcium alginate microcapsules demonstrated significantly enhanced pH and thermal stability.The immobilized enzyme retained 71.77%of its initial enzyme activity after incubation at 70℃ for 3 h.This immobilized enzyme also exhibited remarkable storage stability and reusability,retaining 14.83%of its initial activity after eight consecutive uses.In summary,the proposed calcium alginate micro-capsule immobilization technique for IFTase significantly improved enzyme stability and reusability,offering a practical approach for the industrial production of DFAⅢ.展开更多
基金supported by the Outstanding Youth Science Foundation of Shandong Province(No.ZR2022YQ28)Taishan Young Scholar Program of Shandong Province(NO.tsqn202103104)+2 种基金National Natural Science Foundation of China(No.31972203)Special Funds for Taishan Scholars Project(No.ts201712060)Major Innovation Pilot Project of Integration of Science,Education and Industry of Qilu University of Technology(Shandong Academy of Science)(No.2024ZDZX05,2022JBZ01-08).
文摘Inulin fructotransferase(IFTase),a microbial enzyme,efficiently catalyzes the conversion of inulin into difruc-tose anhydrideⅢ(DFAⅢ).However,the poor stability and reusability of IFTase limits its industrial application.To overcome this challenge,IFTase from Paenarthrobacter aurescens QL1.001 was immobilized in calcium algi-nate microcapsules using the method of emulsification/internal gelation in this work.A systematic optimization of the microcapsule preparation parameters was conducted using a single-factor experimental design,resulting in an optimal formulation:1.5%sodium alginate concentration,a molar ratio of calcium carbonate to sodium alginate(Ca/Alg)of 0.33,a molar ratio of glacial acetic acid to calcium carbonate(acid/Ca)of 5,the enzyme amount of 4 mg,and ferroferric oxide(Fe_(3)O_(4))amount of 10 mg.Furthermore,the particle size of the micro-capsules was regulated via adjusting the stirring speed,revealing that as the stirring speed increased,the particle size decreased gradually,while the recovery of immobilized enzyme remained relatively stable.Compared to the free enzyme,IFTase immobilized within calcium alginate microcapsules demonstrated significantly enhanced pH and thermal stability.The immobilized enzyme retained 71.77%of its initial enzyme activity after incubation at 70℃ for 3 h.This immobilized enzyme also exhibited remarkable storage stability and reusability,retaining 14.83%of its initial activity after eight consecutive uses.In summary,the proposed calcium alginate micro-capsule immobilization technique for IFTase significantly improved enzyme stability and reusability,offering a practical approach for the industrial production of DFAⅢ.
