抗腹泻益生菌T-70-1胞外产抗菌蛋白发酵条件的优化

Optimization of fermentation conditions for production of extracellular antibacterial protein by anti-diarrhea probiotics strain T-70-1

为了提高益生菌T-70-1胞外产抗菌蛋白的产量,试验采用单因素分析法,以抑制大肠杆菌能力为指标,分别考察碳源、氮源、无机盐种类对T-70-1菌株发酵产抗菌蛋白的影响,再结合正交试验法对该菌株胞外产抗菌蛋白的培养基组成和发酵条件进行优化,利用SPSS软件进行方差分析,确定最佳发酵产抗菌蛋白的条件。结果表明：优化后的发酵条件为葡萄糖2.5%、蛋白胨2.0%、Mg SO40.08%、KCl 0.10%;初始p H值为6.5,种子液按照4%接种量接种于装液量为30 m L/250 m L的锥形瓶中,30℃发酵培养32 h。优化后胞外产抗菌蛋白相应的抑菌圈面积增大至525.5 mm2,较优化前增幅达60.7%。说明通过优化发酵条件获得了菌株T-70-1发酵产抗菌蛋白最佳培养基组成和培养条件,抗菌蛋白产量得到了明显提高。

The aim of the present study was to improve the production of extracellular antimicrobial proteins by probiotic strain T-70-1. The activity of inhibiting Escherichia coli was used as an index,the effects of carbon source,nitrogen source and inorganic salt on the fermentation of strain T-70-1 were investigated by single factor analysis. Then the culture medium composition and fermentation conditions of the extracellular antimicrobial protein were optimized by the orthogonal test. The optimal fermentation conditions were obtained by using the SPSS software analysis. The results showed that the optimized fermentation parameters were glucose 2. 5%,peptone 2. 0%,Mg SO40. 08%,KCl 0. 10%,and the initial p H value was 6. 5. The original solution was inoculated in a 250 m L conical flask containing 30 m L culture medium（ 4% inoculation）and then fermented at 30 ℃ for 32 h. After optimization,the area of antibacterial activity of extracellular antimicrobial proteins increased to525. 5 mm2,which was 60. 7% higher than that before optimization. The results indicated that the optimum medium composition and culture conditions were obtained by optimizing the fermentation conditions of strain T-70-1,and the yield of antimicrobial protein was obviously increased.