响应面法优化褐藻胶降解菌Cobetia sp.20发酵培养基

为了提高褐藻胶降解菌株Cobetia sp.20产褐藻胶裂解酶的能力，利用响应面法优化其发酵产褐藻胶裂解酶的培养基。首先利用单因素法分别对发酵培养基中的不同碳源、碳源添加量、不同氮源、氮源添加量以及氯化钠添加量、磷酸二氢钾添加量、硫酸镁添加量和pH进行探究，研究各因素对产酶的影响。在单因素实验的基础上，通过Plackett-Burman试验确定Cobetia sp.20发酵培养基中影响产酶的主要因素。通过响应面试验建立回归方程。研究结果表明，Cobetia sp.20最优发酵培养基配方为褐藻胶15.00 g/L、硫酸铵7.50 g/L、氯化钠15.00 g/L、硫酸镁0.50 g/L、磷酸二氢钾5.30 g/L、硫酸亚铁0.01 g/L、pH值7.58。优化后酶活为142.79 U/mL，比优化前提高了26.36%。褐藻胶裂解酶活的提高，为褐藻胶裂解酶的工业化生产提供了参考。

Optimization of Fermentation Medium of Alginate Degradable Cobetia sp.20 Strain by Response Surface Method

In order to improve the ability of alginate degradable Cobetia sp.20 strain to produce alginate lyase, its fermentation medium was optimized by response surface methodology. Firstly, single factor method was used to explore the effects of different carbon sources, different nitrogen sources, the addition amounts of carbon source, nitrogen source, sodium chloride, potassium dihydrogen phosphate, and ferrous sulfate, as well as pH in fermentation medium on the production of alginate lyase. Based on single factor test and Plackett-Burman test, the main factors affecting the enzyme production of Cobetia sp.20 were determined. The regression equation was established by response surface test, and the results showed that the optimal fermentation medium and conditions for Cobetia sp.20 were as follows: 15.00 g/L sodium alginate, 7.50 g/L ammonium sulfate, 15.00 g/L sodium chloride, 0.50 g/L magnesium sulfate, 5.30 g/L potassium dihydrogen phosphate, 0.01 g/L ferrous sulfate, and pH 7.58. The optimized enzyme activity was 142.79 U/mL, 23.36% higher than that before optimization. After optimization, the activity of alginate lyase produced by Cobetia sp.20 increased significantly, which laid a foundation for the industrial production of alginate lyase.