金银花内生菌EJH-1抗菌作用发酵培养基响应面法优化

Optimization of fermentation medium for antimicrobial activity production by endophytic strain EJH1 from Honeysuckle with response surface methodology

首先采用P lackett-Burm an设计法,对影响金银花内生菌EJH 1抗菌作用发酵的9个相关因素进行了筛选。结果表明,对发酵液抗菌活性具有显著影响的因子是谷氨酸钠和KH2PO4。然后,采用响应曲面法(Response Surface M ethod-ology,RSM)(中心组合设计)对影响抗菌物质发酵的谷氨酸钠和KH2PO4最佳水平及其交互作用进行了研究与探讨。通过模型方程3 D图及其等高线图研究发现,谷氨酸钠和KH2PO4分别在5.12 g.L-1和2.13 g.L-1的条件下,可获得抑菌圈直径的最大预期值20.27 mm。验证试验证实了该方程的预测值与实际值之间吻合较好。优化后的培养基使抗菌活性抑菌圈直径从起始Landy培养基的18.21 mm提高到20.27 mm。

Response surface methodology was used to optimize the submerged fermentation medium of antimicrobial activity production of endophytic strain EJH - 1 from Honeysuckle. In the fist optimization step, a Plackett-Burman design was undertaken to screen the key factors rapidly from the 9 related factors. By analyzing the statistical regression, the sodium glutamate and KH2PO4 were found to be the most important factors for the production of antimicrobial activity. Based on the results of our previous Plackett- Burman design, a five-level two-factor Central Composite design was applied to optimize the production of antimicrobial activity. The critical factors selected for the investigation were mentioned above. By analysis of the 3 - D plots and their corresponding plots, the optimum values of the concentrations of sodium glutamate and KH2PO4 for obtaining the most production of antimicrobial activity were 5.12 g ·L^-1 and 2. 13 g ·L^-1 , respectively. The diameter of antimicrobial circle increased from 18. 21 mm to 20.27 mm in optimized medium condition.