CAJ | 학술논문

在毕赤酵母GS115中表达东方肉座菌EU7-22的β-葡萄糖苷酶基因（bgl?），获得基因工程菌株BP17。优化BP17収酵产酶条件后，重组β-葡萄糖苷酶活力达121 IU/mL。酶学性质研究表明，该酶最适反应温度为70℃，在60℃以下有较好的热稳定性；最适催化pH为5.0，在pH 3.0~8.0之间有较好的稳定性。将异源表达的β-葡萄糖苷酶添加到东方肉座菌的纤维素酶液中协同降解经过预处理的竹纤维，当纤维素酶添加量为FPA 20 IU/g底物，β-葡萄糖苷酶添加量为BG 6 IU/g底物时，纤维二糖浓度显著下降，酶解得率达到83.03%，表明重组β-葡萄糖苷酶的加入更有利于纤维素的酶解糖化。
재필적효모GS115중표체동방육좌균EU7-22적β-포도당감매기인（bgl?），획득기인공정균주BP17。우화BP17수효산매조건후，중조β-포도당감매활력체121 IU/mL。매학성질연구표명，해매최괄반응온도위70℃，재60℃이하유교호적열은정성；최괄최화pH위5.0，재pH 3.0~8.0지간유교호적은정성。장이원표체적β-포도당감매첨가도동방육좌균적섬유소매액중협동강해경과예처리적죽섬유，당섬유소매첨가량위FPA 20 IU/g저물，β-포도당감매첨가량위BG 6 IU/g저물시，섬유이당농도현저하강，매해득솔체도83.03%，표명중조β-포도당감매적가입경유리우섬유소적매해당화。
Theβ-glucosidase gene (bglI) from Hypocrea orientalis EU7-22 was cloned and effectively expressed in Pichia pastoris GS115. The ?-glucosidase activity expressed by recombinant strain BP17 reached 121 IU/mL. The expressed ?-glucosidase exhibited the optimum catalytic activity at 70°C and pH 5.0. The enzyme exhibited good stability at pH 3.0~8.0 and remained 65%of its original activity after 1 h at 60°C. The pretreated bamboo cellulose was synergistic hydrolyzed by the cellulases from Hypocrea orientalis EU7-22 and the recombinantβ-glucosidase from strain BP17. Supplementing recombinant β-glucosidase greatly reduced the inhibitory effect caused by cellobiose, and the hydrolysis yield was improved to 83.03% with enhanced β-glucosidase activity of 6 IU/g substrate. The results indicated the recombinantβ-glucosidase significantly boost the efficiency of saccharification.