连续静置培养促进大肠杆菌生长和运动

Continuous static culture promotes rapid growth and motility of Escherichia coli

大肠杆菌繁殖速度快、基因结构简单,已构建出黏性鞭毛的突变体,是一种研究鞭毛运动的模式生物。大肠杆菌能对外界环境的变化做出响应,是其赖以生存的基础,其中很重要的就是其生长和运动行为的变化。为了研究连续营养作用下的大肠杆菌生长和运动的情况,文章采用连续5 d静置液体培养大肠杆菌,通过定期检测菌液OD值的方法获得大肠杆菌的生长曲线,发现大肠杆菌生长到达稳定期的时间随培养天数增加而缩短;观察连续5 d静置液体培养的大肠杆菌在稳定期的形态变化,发现大肠杆菌的形态并不受生长和运动的影响。利用倒置显微镜结合乳胶小球标记鞭毛技术观察大肠杆菌在稳定期的鞭毛马达的转动过程,发现随着培养天数的增加,大肠杆菌鞭毛马达的转速加快,说明连续营养培养会促进大肠杆菌鞭毛马达的运动性;后续的群体运动实验进一步验证了该结论。在该基础上,研究发现大肠杆菌运动能力的实现需要相关的基因,包括motB和fliC。该文为发现营养在大肠杆菌生长运动中的作用提供了相关的科学依据,为深入研究大肠杆菌的鞭毛运动与肠道营养之间的关系提供了潜在的途径。

Escherichia coli breeds fast and has a simple gene structure.Mutants of viscous flagella have been constructed,which is a model organism for studying flagellar movement.E.coli can respond to changes in the external environment,which is the basis for its survival,and the most important thing is the changes in its growth and movement behavior.In order to study the growth and movement of E.coli under the effect of continuous nutrition,this study used static liquid culture of E.coli for five consecutive days,and obtained the growth curve of E.coli by regularly detecting the OD value of the bacterial solution.It was found that the growth of E.coli reached a stable level.The period of time shortened with the increase of the number of culture days.Observing the morphological changes of E.coli in the static liquid culture for five consecutive days,it was found that the morphology of E.coli was not affected by growth and movement.Using an inverted microscope combined with latex beads technology,the rotation process of the flagellar motor of E.coli in the stable phase was observed.It was found that the rotation speed of the flagellar motor of E.coli increased with the increase of culture days,indicating that continuous nutrient culture would promote the flagellar motor sports;follow-up group sports experiments further verified this argument.On this basis,this study found that the realization of E.coli motor ability required related genes,including motB and fliC.This study provides a scientific basis for discovering the role of nutrition in the growth and movement of E.coli,and provides a potential way for in-depth study of the relationship between the flagellar movement of E.coli and enteric nutrition.