响应面优化转透明颤菌血红蛋白基因里氏木霉液体发酵产纤维素酶的培养条件

Optimization of Culture Condition in Trichoderma reesei Tu6-VHb Which Transferred VHb Gene Cellulase Production by Surface Method

研究采用响应面法并以滤纸酶活力(filter paper activity,FPA)作为响应值对转透明颤菌血红蛋白基因的里氏木霉(Trichoderma reesei)Tu6-VHb菌株液体发酵产纤维素酶的发酵条件进行优化。根据单因素试验结果设计P-B试验,筛选出影响Tu6-VHb菌株发酵产酶的3个显著因素:吐温-80含量、发酵液体积(250 mL三角瓶发酵)、氮源浓度。用最陡爬坡路径法逼近最大响应值区域,运用响应面B-B试验设计确定3个显著因素之间的交互作用和最佳发酵条件。结果显示,Tu6-VHb产纤维素酶的最佳发酵条件是:吐温-80含量0.39%,发酵液体积61.32mL(250 mL三角瓶发酵),氮源浓度0.87%。经优化后,Tu6-VHb菌株发酵产纤维素酶酶活力达51.72U/mL,与模型预测值51.94U/mL相近,较优化前该菌株酶活力(39.984U/mL)提高了29.35%,是未转入透明颤菌血红蛋白基因的里氏木霉(Trichoderma reesei)Tu6菌株酶活力(35.904U/mL)的1.44倍。

In this study,the culture condition of Trichoderma reesei Tu6-VHb liquid fermentation to produce cellulases were optimized by response surface method and using filter paper activity（FPA）as the response value.First,three significant factors of enzyme production were screened by P-B test according to single factors＇ result which were Tween-80 content,fermentation volume（250 mL triangular flask fermentation）and nitrogen source concentration.Then approached the maximum response area by the path of steepest ascent method.Finally,the response surface method was used to determine the interaction between each two main factors and optimum formula of culture medium.The results showed that the optimized fermentation condition in Tu6-VHb producing cellulase were that Tween-80 content was 0.39%,fermentation volume（250 mL triangular flask fermentation）was 61.32 mL and nitrogen source concentration was 0.87%.After fermentation,the cellulase activity produced by Tu6-VHb could be up to 51.72 U/mL,which close to the model prediction（51.94 U/mL）,29.35% higher than that before optimization（39.984 U/mL）,and 1.44 times of that of Trichoderma reesei Tu6 strain without Trichoderma reticum hemoglobin gene（35.904 U/mL）.