响应面法优化德氏乳杆菌保加利亚亚种增殖培养基

Optimization of A Culture Medium for Cell Multiplication of Lactobacillus delbrueckii subsp bulgaricus LB14 Using Response Surface Methodology

采用响应面方法对德氏乳杆菌保加利亚亚种LB14增殖培养基进行了优化。以MRS培养基作为基础培养基,采用Plackett-Burman(PB)设计法,对12种乳酸菌生长促进因子以及培养基的初始pH等13个因素对德氏乳杆菌保加利亚亚种LB14生长的影响进行评价。筛选出番茄汁与胡萝卜汁为LB14的生长强化因子,且培养基的初始pH值也是影响该菌体生长的关键因子,而其它物质对LB14增菌量的影响不显著。然后用旋转中心组合设计及响应面分析法确定强化因子的最佳浓度以及最佳的培养基初始pH值。在优化培养基中,LB14的菌体浓度达到1.1×109cfu/ml,比优化前的2.4×108cfu/ml提高了近5倍。

Response surface methodology was used to optimize the MRS-based culture medium of L. delbrueckii subsp bulgaricus LB14. The effects of twelve additives and the initial pH of the media were evaluated by using a Plackett-Burman design. Results showed that tomato juice, carrot juice and the initial pH of the media were the main affecting factors while the other additives had no significant effect on the cell multiplication of LB14. Then, the central composite design and response surface analysis were used to determine the optimal levels of the main factors. The optimized conditions were:MRS supplemented with 52.4ml/L tomato juice and 28.1ml/L carrot juice,and the initial pH of the media was 6.38. It resulted in cell production of LB14 to be increased from 2.4×108cfu/ml to 1.1×109cfu/ml.