响应面法优化短小芽孢杆菌SCU11发酵产碱性蛋白酶及关键基因转录调控分析

发布时间：2018-07-10 06:18

  本文选题：响应面法 + 短小芽孢杆菌　； 参考：《应用与环境生物学报》2016年03期

【摘要】：短小芽孢杆菌SCU11是由本实验室分离的野生菌株BA06经过复合诱变得到的高产碱性蛋白酶菌株,其产生的碱性蛋白酶在生物制革领域具有很好的应用前景.为进一步提高菌株的蛋白酶产量以满足工业生产的需求,本研究利用响应面法优化菌株产蛋白酶的发酵培养条件.在前期单因素实验的基础上,通过Plackett-Burman实验设计、最陡爬坡实验、中心组合实验设计和响应面分析法,确定了当黄豆粉浓度为53.3 g/L,温度为28℃时,蛋白酶活有理论最大值8 884 U/m L,摇瓶实验验证酶活为8 768 U/m L,达到理论预测值的98.7%,比优化前酶活提高了1倍.为了解优化的发酵条件使蛋白酶产量提高的原因,对短小芽孢杆菌蛋白酶基因及相关调控基因的表达情况进行荧光定量PCR分析,结果显示,优化后5种蛋白酶基因的表达量上调,1种表达量下调;5种蛋白酶相关调控基因的表达量增加,2种基因表达量降低.推测是优化后正调控基因表达量的增加以及负调控基因表达量的降低,促进了短小芽孢杆菌胞外蛋白酶基因转录水平的提高,导致胞外蛋白酶产量增加.本研究采用响应面法优化发酵条件使短小芽孢杆菌SCU11蛋白酶产量提高了1倍,并为阐明其表达调控机制奠定了基础.(图3表7参24)
[Abstract]:Bacillus pumilus SCU11 is a high-yielding alkaline protease strain isolated from the wild strain BA06 in our laboratory. The alkaline protease produced by SCU11 has a good application prospect in the field of biological tannery. In order to further improve the protease production of the strain to meet the needs of industrial production, the response surface method was used to optimize the fermentation and culture conditions of the protease production of the strain. On the basis of the previous single-factor experiments, the Plackett-Burman experiment, the steepest climbing experiment, the central combination experiment design and the response surface analysis, the results show that when the concentration of soybean powder is 53.3 g / L and the temperature is 28 鈩，

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