发酵条件对植物乳杆菌叶酸合成的影响

Effects of Different Fermentation Conditions on Folate Synthesis of Lactobacillus plantarum

选择1株高产叶酸的植物乳杆菌4-3,探讨在脱脂奶和豆浆两种发酵基质中,不调节pH值和使pH值稳定在6.0对其生长状况和叶酸合成的影响。结果显示,以豆浆为发酵基质时叶酸含量更高;控制培养基pH 6.0,植物乳杆菌4-3在其生长对数期后仍然可以保持较高的活细胞密度,且促进叶酸的积累。实时荧光定量聚合酶链式反应结果显示,控制pH 6.0能促进叶酸合成相关基因的表达。

In this study,Lactobacillus plantarum 4-3,producing folate at high yield,was investigated for the effects of natural pH and maintaining pH at 6.0 on its growth status and folate synthesis in skim milk or soybean milk.The results showed that strain 4-3 produced more folate when cultured in soybean milk.When the culture pH was controlled at 6.0,this strain could still maintain high cell density after the logarithmic growth phase and showed enhanced accumulation of folate.Real-time fluorescence quantitative polymerase chain reaction(qPCR)results showed that the expression levels of folate biosynthesis-related genes were higher at constant pH.