以豆粕为基质纳豆芽孢杆菌生长条件优化

研究纳豆芽孢杆菌在以豆粕为基质的发酵培养基中的生长条件。利用全自动生长曲线测定仪，以菌液浊度OD660nm为指标，对纳豆芽孢杆菌液体发酵培养基中的氮源(豆粕)和碳源(葡萄糖)配比进行研究，确定豆粕质量浓度50g/L，葡萄糖质量浓度10g/L为最佳配比，并通过单因素及正交试验筛选出影响纳豆芽孢杆菌生长的主要条件。再根据Box-Behnken试验优化，结果表明，采用功率80W超声波处理豆粕4.32min，且培养基初始pH6.16，发酵温度35.5℃时纳豆芽孢杆菌在发酵生长13h后达到最大生物量，此时OD660nm为1.635。

Optimization of Culture Conditions for the Growth of Bacillus subtilis natto Utilizing Soybean Meal as Nitrogen Source

Cell suspension turbidity(optical density at 660 nm,OD660 nm) was measured using an automated growth curve analyzer to investigate the growth of Bacillus subtilis natto during incubation in a liquid culture medium composed of soybean meal as nitrogen source and glucose as carbon source.The optimal concentrations of soybean meal and glucose were found to be 50 g/L and 10 g/L,respectively.Using one-factor-at-a-time combined with orthogonal array design method,temperature,pH and time were identify as major factors that influence the growth of Bacillus subtilis natto.Further,Box-Behnken experimental design was used to optimize the main influencing factors.Bacillus subtilis natto achieved the highest biomass after 13 h of incubation at initial pH 6.16 and 35.5 ℃ in the presence of soybean meal treated by ultrasonic for 4.32 min,and the cell suspension turbidity was 1.635 under these conditions.