文献类型：期刊文献

英文题名：Characterization of enzyme-immobilized catalytic support and its exploitation for the degradation of methoxychlor in simulated polluted soils

作者：Huang, Yan[1];Li, Jie[1];Yang, Yuxiang[1,2];Yuan, Hongming[3];Wei, Qinmei[1];Liu, Xiangnong[4];Zhao, Yi[1];Ni, Chaoying[2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[2]Univ Delaware, Dept Mat Sci & Engn, Newark, DE 19716 USA;[3]Jilin Univ, State Key Lab Inorgan Synth & Preparat Chem, Changchun 130012, Jilin, Peoples R China;[4]Yangzhou Univ, Anal Test Ctr, Yangzhou 225009, Jiangsu, Peoples R China

年份：2019

卷号：26

期号：27

起止页码：28328

外文期刊名：ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

收录：;EI(收录号：20242616401371);WOS:【SCI-EXPANDED(收录号:WOS:000490028900068)】；

基金：This work was supported by the National Natural Science Foundation of China (20577010, 20971043), the Fundamental Research Funds for the Central Universities, and the Open Project Program of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University.

语种：英文

外文关键词：Chiral mesoporous silica; Graphene oxide; Immobilized enzyme; Compound enzyme; Degradation of methoxychlor

摘要：Chiral mesoporous silica (SiO2) with helical structure was synthesized by using anionic surfactants as template. Pre-prepared graphene oxide (GO) was then loaded onto SiO2 to synthesize composite carrier chial-meso-SiO2@GO for the immobilization of laccase. The enzyme activity, thermostability, acid stability, and repeatability of the immobilized enzyme were significantly improved after immobilization. The chial-meso-SiO2@GO-immobilized laccase was then used for the degradation of MXC in aqueous phase. The degradation conditions, including temperature, time, pH, MXC concentration, and the dose of immobilized enzyme for cellulosic hydrolysis, were optimized. The optimum conditions for degradation of methoxychlor were selected as pH 4.5, MXC concentration 30 mg/L, immobilized enzyme dose 0.1 g, the maximum MXC removal of over 85% and the maximum degradation rate of 50.75% were achieved after degradation time of six h at temperature of 45 degrees C. In addition, the immobilized cellulase was added into the immobilized laccase system to form chial-meso-SiO2@GO-immobilized compound enzyme with the maximum MXC degradation rate of 59.58%, higher than that of 50.75% by immobilized laccase. An assessment was made for the effect of chial-meso-SiO2@GO-immobilized compound enzyme on the degradation of MXC in soil phase. For three contaminated soils with MXC concentration of 25 mg/kg, 50 mg/kg, and 100 mg/kg, the MXC removals were 93.0%, 85.8%, and 65.1%, respectively. According to the GC-MS analyses, it was inferred that chial-meso-SiO2@GO-immobilized compound enzyme had a different degradation route with that of chial-meso-SiO2@GO-immobilized laccase. The hydrolysis by immobilized cellulase might attack at a weak location of the MXC molecule with its free radical OH and ultimately removed three chlorine atoms from MXC molecule, leading to generating small molecular amount of degradation product.