半乳糖三寡糖及pH值对乳酸杆菌生长的影响

Effect of galactooligosaccharides and pH on growth of lactobacilli

目的 :探讨半乳糖三寡糖对乳酸杆菌的增殖作用及 p H值对乳酸杆菌生长繁殖的影响。方法 :经柱层析分离纯化得到纯半乳糖三寡糖 ,以 1、2、3、4、5、6、7、8g/L分别用于体外乳酸杆菌培养试验。乳酸杆菌厌氧培养时测定菌体浓度与 p H值 ,绘制生长曲线和p H值曲线 ,观察 p H值对乳酸杆菌生长的影响。用碱回调法将乳酸杆菌菌种培养液 p H值分别调至 5、6、7,与 p H4.0菌种生长液作对比 ,分别测定菌种保藏期。结果 :浓度为 5 g/L的半乳糖三寡糖对乳酸杆菌生长的促进作用比对照组高出 3.7倍。 p H值下降到 3.75～ 4.0时 ,乳酸杆菌大量减少。碱回调至 p H6.0时菌种低温 ( 4℃ )下保藏期从 1 2周延至 2 2周。结论 :半乳糖三寡糖能高效地促进乳酸杆菌的生长繁殖 ,p H值 6.0时有利于其体外生长及菌种保藏。

Objective: To study the effect of galactooligosaccharides on multiplication of lactobacilli and the influence of pH on lactobacilli growth and preservation. Methods: Trisaccharide was purified by column chromatography and was added to basic medium for lactobacilli cultivation with 1, 2, 3, 4, 5, 6, 7, 8 g/L, respectively. The thallus concentration and pH were detected for drawing the growth curve and pH curve. Then the pH of basic medium was adjusted to 5, 6, 7 by alkali and the preservation time was recorded. Results: Trisaccharide could promote the multiplication of lactobacilli 3.7 times as effectively as control group. The number of lactobacilli decreased greatly when the pH of culture was below 4.0, and the preservation time increased from 12w to 22w when the pH of basic culture was adjusted to 6. Conclusion: Trisaccharide of galactooligosaccharides could remarkably promote the multiplication of lactobacilli, and it is benefit to the growth and preservation when pH of lactobacilli medium was regulated to 6.0.