Effects Of Simulated Microgravity On Escherichia Coli And Its Mechanism

The effect of simulated microgravity on growth characteristics and exogenous protein expression of Escherichia coli was studied.The effects of culture conditions,which are shear stress and microenvironment on simulated microgravity,were explored.The experiments were divided into two groups: the experiment group of the vertical gravity vector direction of the rotation axis and the control group of the parallel gravity vector direction of the rotation axis,both of which were cultured on the clinostat to explore the combined effects of simulated microgravity culture.The effects of shear stress on the growth and the expression of exogenous protein were studied.The gene encoding flagellum was knocked out to construct the motility mutant strain,and the effects of motility on the growth and the expression of exogenous protein were studied.The xylose and lactose biosensor were used to study the effect of bacterial microenvironment on the growth of the strain and the expression of exogenous protein.The results showed that compared with the control group,the microgravity culture accelerated the growth of bacteria,increased the biomass and increased the expression of exogenous protein.The low shear stress condition had no obvious effect on the growth of bacteria.And the concentration of the nutrient in the microenvironment under simulated microgravity was higher than that in the control group under simulated microgravity condition.The microgravity environment could promote the growth and protein expression,and the mechanism was not related to the shear stress.The main reason may be caused by the difference of nutrient concentration in the microenvironment.