School of Science, Zhejiang Sci-tech University, Hangzhou, China.
J Microbiol Biotechnol. 2010 Apr;20(4):835-43.
The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exo-polysaccharides from Inonotus obliquus by response surface methodology. A two-level fractional factorial design was used to evaluate the effect of different components of medium. Corn flour, peptone, and KH2PO4 were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, KH2PO4 0.26, MgSO4 0.02, and CaCl2 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%.
本研究旨在通过响应面法研究发酵培养基成分对桦褐孔菌胞外多糖清除羟自由基活性的影响。采用两水平部分因子设计评估培养基不同成分的影响。玉米粉、蛋白胨和 KH2PO4 是显著影响羟自由基清除活性的重要因素。随后，采用最陡爬坡法（下降法）、中心复合设计和响应面分析对这些选定变量进行优化。最佳培养基组成为（w/v）：玉米粉 5.30%、蛋白胨 0.32%、KH2PO4 0.26%、MgSO4 0.02%和 CaCl2 0.01%。在最佳条件下，羟自由基清除率（49.4%）明显高于基础发酵培养基（10.2%）和发酵培养基单变量优化（35.5%）。RSM 优化多糖的主要单糖组分为鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖，摩尔比例分别为 1.45%、3.63%、2.17%、15.94%、50.00%和 26.81%。
