%0 Journal Article
%T Cloning, expression and characterization of a beta-glucosidase from Geobacillus thermodenitrificans<br>嗜热脱氮土壤芽孢杆菌β-葡萄糖苷酶的克隆与重组表达及其酶学性质研究
%A HU Kai-lei
%A HAN Jian
%A LIU Wei-feng
%A WANG Yan-ping
%A TAO Yong
%A <br>胡开蕾
%A 韩剑
%A 刘伟丰
%A 王艳萍
%A 陶勇
%J 微生物学通报
%D 2012
%I 
%X Objective] Cloning of β-glucosidase gene bglB from Geobacillus thermodenitrifi-cans,heterologous expression in E.coli,purification and characterization of its enzymatic properties.Methods] Molecular cloning of the β-glucosidase encoding gene(bglB) from Geobacillus thermodenitrificans was performed by using a PCR technique.The gene was ex-pressed in BL21(DE3) of Escherichia coli.After purification,the enzymatic properties and the protein aggregation of β-glucosidase was investigated.Results] The optimum temperature and optimum pH of the recombinant β-glucosidase are 65 °C and 7.0 respectively,the enzyme is stable for 4 h under the conditions of pH 5?10,60 °C,and it maintains its high enzymatic activity at the high salt concentration(up to 880 mmol/L K+).The recombinant β-glucosidase is strongly activated by Al3+,while slightly inhibited by Co2+.Under the optimal reaction con-dition,the enzyme specific activity of recombinant β-glucosidase is 0.043 IU/mg.The β-glucosidase GST fusion protein exists in different oligomers by a Superdex G-200 gel filtra-tion analysis,and the different oligomers of enzymes all have hydrolase activity.Conclusion] We successfully obtained a heat-and salt-resistant neutral recombinant β-glucosidase from Geobacillus thermodenitrificans,and paved a way for further study of its catalytic mechanism and improvement its thermal stability of beta-glucosidase.
%K β-glucosidase
%K Geobacillus thermodenitrificans
%K Recombinant expression
%K Heat-resis-tant
%K Salt-resistant<br>β-葡萄糖苷酶
%K 嗜热脱氮土壤芽孢杆菌
%K 重组表达
%K 耐热
%K 耐盐
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=78024727B5F4EF6AA9CA8E605B5FC464&aid=D8F424933EF6BDDE0FAD3AC58B4B6124&yid=99E9153A83D4CB11&vid=7C3A4C1EE6A45749&iid=DF92D298D3FF1E6E&sid=A5EF91F3C4847AE5&eid=E9A4A9F8141B400C&journal_id=0253-2654&journal_name=微生物学通报&referenced_num=0&reference_num=0