响应面法优化海洋枯草芽孢杆菌HS-A38增殖发酵培养基

在摇瓶培养条件下,优化提高海洋枯草芽孢杆菌菌体浓度的发酵培养基组分。采用Plackett-Burman法确定了影响菌体浓度的显著性因子,即葡萄糖和ZnSO4;通过最陡爬坡实验逼近这两个重要因子的最大响应稳定区域,采用中心组合实验确定显著性因子的最佳水平,并用Design expert 7.13软件进行回归分析。优化后培养基的组成为:葡萄糖8.49g/L,豆粕粉12.0g/L,尿素0.625g/L,酵母膏4.0g/L,K2HPO44.0g/L,ZnSO40.053g/L。优化后的活菌浓度达到1.64×109 cfu/mL,与优化前菌体浓度(7.22×108 cfu/mL)相比,提高了1倍多。通过统计优化培养基组分可有效提高海洋枯草芽孢杆菌HS-A38的发酵液菌体浓度。

Medium optimization for spore production of marine Bacillus subtilis HS-A38 by response surface methodology

Using shaking-flask fermentation in the laboratory,glucose and ZnSO4 affecting spore production of marine Bacillus subtilis HS-A38 were determined by the design of Plackett-Burman.The region of the fermentation conditions was approached through the path of steepest ascent.Subsequently,the concentration of those important factors were optimized by Central Composite Design(CCD) and response surface analysis by Design expert 7.13.The concentration of ingredients is as glucose 8.49 g/L,soybean powder 12.0 g/L,urea 0.625 g/L,yeast extract 4.0 g/L,K2HPO4 4.0 g/L,ZnSO4 0.053 g/L.The colony-forming units per milliliter(cfu/mL) were improved from 7.22×108 to 1.64×109 after medium optimization,and the yield of cfu/mL is increased by more than one time.This study suggests that the spore concentration can be improved by the experimental designs.