Purification and Characterization of β-Glucosidase from a Newly Isolated Strain Tolypocladium cylindrosporum Syzx4  

作　　者：ZHANG Yi-bo YUAN Li-jia CHEN Zhao-jie FU Lu LU Jia-hui MENG Qing-fan HE Huan YU Xiao-xiao LIN Feng TENG Li-rong 

机构地区：[1]Key Laboratory for Molecular Enzymology ＆ Engineering, Ministry of Education, College of Life Science, Jilin University, Changchun 130012, P. R. China [2]Department of Endocrinology, Chian-Japan Union Hospital of Jilin University, Changchun 130033, P. R. China

出　　处：《Chemical Research in Chinese Universities》2011年第4期557-561,共5页高等学校化学研究（英文版）

基　　金：Supported by the Important Agriculture Program of the Jilin Province Technology Department,China(No.20096013);the Jilin University Basic Science Research Fund,China(No.200903259);the Graduate Innovation Fund of Jilin University,China (No.20101043);the Project of Jilin Fuel Alcohol Company Ltd.,China

摘　　要：A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer（ITS） rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight（Mw） of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km（0.85 mmol/L） and vmax[85.23 mmol/（L·s）] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside（p-NPG） as the substrate,inhibition constant Ki（39.5 mmol/L） with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation（SSF）.A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer（ITS） rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight（Mw） of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km（0.85 mmol/L） and vmax[85.23 mmol/（L·s）] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside（p-NPG） as the substrate,inhibition constant Ki（39.5 mmol/L） with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation（SSF）.

关 键 词：Β-GLUCOSIDASE PURIFICATION CHARACTERIZATION Thermoacidophilic Tolypocladium cylindrosporum syzx4 

分 类 号：TQ925.9[轻工技术与工程—发酵工程] Q554.9[生物学—生物化学]