海南土地杆菌Pedobacter hainanensis 13-Q^T发酵生产κ-卡拉胶酶的条件优化

Optimization of fermentation condition for κ-carrageenase producing by Pedobacter hainanensis 13-Q^T

采用响应面法对海南土地杆菌Pedobacter hainanensis 13-QT生产κ-卡拉胶酶的发酵条件进行了优化,通过Plackett-Burman实验方法研究碳源含量、氮源含量、无机盐、初始pH值、温度等9个发酵因子对菌株发酵产κ-卡拉胶酶活力的影响。结果表明,影响产酶的显著因子是温度、蛋白胨浓度和初始pH值。根据最陡爬坡实验结果确定显著影响因子的取值范围,并采用Box-Behnken设计实验进行优化,然后应用响应面模拟预测和摇瓶发酵实验验证。结果表明,产κ-卡拉胶酶的最佳条件为κ-卡拉胶1.5g/L,蛋白胨3.9g/L,NaCl 20g/L,K2HPO41g/L,MgSO40.40g/L,CaCl20.12g/L,FeSO40.008g/L,发酵培养基初始pH值为6.9,温度30.3℃。经过优化后,发酵液中κ-卡拉胶酶酶活力达到3.387IU/mL,与优化前相比提高了5.04倍。

Response surface design was employed to optimize the fermentation conditions of κ-carrageenase production by Pedobacter hainanensis 13-Q^T There were 9 factors affected the κ -carrageenase production, including the concentration of carbon source, nitrogen source, inorganic salts, fermentation temperature and initial pH. The influence of the 9 factors was evaluated by Plackett-Burman design. The results showed that fermenta- tion temperature, initial pH and the concentration of nitrogen source played important roles in the κ-carrageenase production. According to the results of Plackett-Burman design and steepest ascent experiment, the value range of the significant influential factors could be determined. Box-Behnken design was used to optimize these factors and the results were shown in response surface graph. Following the results, the optimum conditions listed as follows： κ-carrageen 1.5g/L, peptone 3.9g/L, NaCl 20g/L, K2HPO4 1g/L, MgSO4 0.4g/L, CaCl2 0.12g/L, FeSO4 0.008g/L, fermentation temperature 30.3℃ and initial pH value 6.9. Under the optimum conditions, 3,387IU/ml of κ-carrageenase was produced by Pedobacter hainanensis 13-Q^T, which was higher 504% than the control.