文献类型：期刊文献

中文题名：pH值对绿色木霉(Trichoderma viride)产纤维素酶的影响

英文题名：Influence of pH on cellulase production by Trichoderma viride in shaking flask culture

作者：耿冰[1];郭美锦[1];张嗣良[1];王永红[1];储炬[1];庄英萍[1]

机构：[1]华东理工大学生物反应器工程国家重点实验室,上海200237

年份：2008

卷号：38

期号：5

起止页码：1

中文期刊名：工业微生物

外文期刊名：Industrial Microbiology

收录：北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；

基金：上海市科委重大专项(05DZ19326)

语种：中文

中文关键词：β-葡萄糖苷酶;拉曼光谱;pH控制;纤维素酶

外文关键词：β-glucosidase; Raman spectra; pH control; cellulase

摘要：采用微晶纤维素为唯一诱导性碳源,对绿色木霉(Trichoderma viride)在摇瓶发酵过程中控制与不控制pH产纤维素酶进行比较。控制pH时胞外蛋白浓度为0.72 mg/mL比不控制pH时提高43%;FPA、EG、CB和CBH酶活为15.0U/mL,120.0U/mL,1.75U/mL,0.85U/mL分别是不控制pH时的2.1、2.3、11.7和1.7倍。在不同pH下测定纤维素酶液各酶活,表明pH值显著影响纤维素酶各单酶酶活。在pH2.7时,β-葡萄糖苷酶酶活仅为pH4.8时酶活的4%;pH回调试验结果表明β-葡萄糖苷酶对pH敏感,并在催化功能上发生不可逆变化。对纤维素酶液添加分离得到的各单酶,当添加β-葡萄糖苷酶时最多可以提高FPA酶活20%。因此β-葡萄糖苷酶是影响综合酶活的关键酶。通过拉曼光谱检测出β-葡萄糖苷酶在pH5.0有活性状态下,酶蛋白主链结构主要为α-螺旋和无规则卷曲;在pH2.0没有活性状态下,酶蛋白主链结构的无规则卷曲发生较大变化,α-螺旋也受到一定影响。这说明pH对β-葡萄糖苷酶构象的改变是造成其活性变化的主要原因。
Cellulase can be produced inducibly by Trichoderma viride with avicel as the sole carbon source. Under the condition of pH value controlled at 4.8, total protein concentration in supematant was 0.72mg/mL,43% higher as compared with that without pH control. The activities of FPA, EG, CB, CBH reached 15.0U/mL, 120.0U/mL, 1.75U/mL and 0.85U/mL, respectively, which were 2.1,2.3,11.7,1.7 times of corresponding values without pH control. After different pH treatment,cellulase activity changed remarkably. Each component activity of cellulase declined with decreasing pH value below 4.8, especially β-glucosidase （CB） activity remained only 4% of the activity at pH4.8. Results of pH returning experiment showed that β-glucosidase was sensitive to pH and led to irreversible denaturation in the catalysis function. In vitro addition of （xmg^onent cellulase, filter paper activity （FPA） was increased by 20% with β-glucosidase supplement, indicating that CB was one of key factors for FPA activity.The characterization of Raman spectra of β-glucosidase solution at pH5.0 arfl pH2.0 was analyzed. It showed that at pl-l5.0 with catalysis activity, principal chain structure of β-glucosidase contained a-helical and disordered structure; at pH2.0 without catalysis activity, principal chain structure β-glucosidase was only composed of a-hdical. That was the main reason why the activity of β-glucosidase changed at different pH.