Biolubricant production from castor oil in a magnetically stabilized fluidized bed reactor using lipase immobilized on Fe3O4 nanoparticles
Biolubricant production from castor oil in a magnetically stabilized fluidized bed reactor using lipase immobilized on Fe3O4 nanoparticles
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DOI：
10.1016/j.indcrop.2016.09.030
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发表时间：
2016-12-30
影响因子：
5.9
通讯作者：
Vahabzadeh, Farzaneh
中科院分区：
文献类型：
--
作者：
Hajar, Mohamad;Vahabzadeh, Farzaneh
在功能化磁性纳米颗粒(MNPs)上共价固定化了假丝酵母菌脂肪酶，并用透射电子显微镜、X射线衍射仪、傅立叶变换红外光谱和VSM分析对其结构进行了表征。固定化脂肪酶(mNPs-IL)的蛋白质负载量和固定化效率分别为38 mg蛋白/g和95%，比活力为2.4U/mg蛋白。研究了磁稳化床反应器(MSFBR)中酶转化蓖麻油制备生物清洗剂的过程。MNPs-IL在反应器中的性能受磁场强度和液体流速的影响。考察了加酶量、底物摩尔比、反应温度等因素对反应的影响。在最佳反应条件下反应24 h，甲酯的收率为96.9%。参考乒乓球的生物催化机理，考虑底物抑制作用，建立了生物催化模型，得到了动力学参数：V-max=6.64mmoL/L min，K-m，K-油=219.16 mmoL/L，K-m，K-甲醇=881.34 mmoL/L，K-i，K-油=1305.74 mmoL/L，K-i，K-甲醇=623.15 mmoL/L，并对数据进行了统计分析，证实了模型的合理性。在MSFBR中MNPs-IL的可重用性测试中，在连续运行8次后保留了87%的初始活性。(C)2016爱思唯尔B.V.保留所有权利。
Candida rugosa lipase was covalently immobilized onto functionalized magnetic nanoparticles (MNPs), and the particles were structurally characterized by TEM, XRD, FTIR, and VSM analyses. The MNPs-immobilized lipase (MNPS-IL) possessed a specific activity of 2.4 U/mg protein when the protein loading and immobilization efficiency were 38 mg protein/g MNPs and 95%, respectively. The enzymatic conversion of castor oil to biolubricant in a magnetically stabilized fluidized bed reactor (MSFBR) was studied. The performance of MNPs-IL in the reactor was affected by the magnetic field strength and liquid flow rate. The effect of other reaction variables, such as enzyme amount, substrate molar ratio, and temperature, were also determined. A 96.9% methyl ester yield was obtained after 24 h reaction under the optimum conditions. The biocatalysis was modeled with reference to the ping-pong bi-bi mechanism and considering substrate inhibition, and the following kinetic parameters were obtained: V-max = 6.64 mmol/L min, K-m,K-oil = 219.16 mmol/L, K-m,K-methanol = 881.34 mmol/L, K-i,K-oil = 1305.74 mmol/L, and K-i,K-methanol = 623.15 mmol/L. The data were statistically analyzed, and the adequacy of the suggested model was confirmed. In a reusability test of the MNPs-IL in the MSFBR, 87% of the initial activity was retained after eight consecutive runs. (C) 2016 Elsevier B.V. All rights reserved.