Centre for Advanced Studies in Botany, University of Madras , Guindy Campus, Chennai 600 025 , India.
Braz J Microbiol. 2011 Apr;42(2):818-24. doi: 10.1590/S1517-838220110002000050. Epub 2011 Jun 1.
The production of halophilic thermostable protease by Haloferax lucentensis VKMM 007 was optimized using a statistical approach. In accordance with factorial design, soluble starch, gelatin, KCl and MgSO4 were selected among 27 variables tested. Next, a second-order quadratic model was estimated and optimal medium concentrations were determined based on quadratic regression equation generated by model. These were 5.14 g L(-1) of KCl, 6.57 g L(-1)of MgSO4, 9.05 g L(-1)of gelatin and 5.27 g L(-1)of soluble starch in high salts media supplemented with 0.5% (w/v) of beef extract and peptone, respectively. In these optimal conditions, the obtained protease concentration of 6.80 U mL(-1) was in agreement with the predicted protease concentration and was further improved to 7.02 U mL(-1) by increasing the concentration of NaCl in the medium to 25% (w/v). An overall 4.0-fold increase in protease production was achieved in the optimized medium compared to activity obtained in initial medium.
采用统计学方法对盐生嗜热菌 Haloferax lucentensis VKMM 007 产嗜热碱性蛋白酶进行了优化。根据析因设计，在 27 种测试变量中选择了可溶性淀粉、明胶、KCl 和 MgSO4。然后，对二次二次模型进行了估算，并根据模型生成的二次回归方程确定了最佳培养基浓度。这些最佳条件为高盐培养基中分别添加 0.5%（w/v）牛肉膏和蛋白胨的 KCl（5.14 g L(-1)）、MgSO4（6.57 g L(-1)）、明胶（9.05 g L(-1)）和可溶性淀粉（5.27 g L(-1)）。在这些最佳条件下，获得的蛋白酶浓度为 6.80 U mL(-1)，与预测的蛋白酶浓度一致，通过将培养基中 NaCl 的浓度提高到 25%（w/v），进一步提高到 7.02 U mL(-1)。与初始培养基相比，优化后的培养基中蛋白酶的产量提高了 4 倍。
