E.coli DH5 alpha Cell Response to a Sudden Change in Microfluidic Chemical Environment

Motile bacteria respond to changing chemical environment by moving towards or away from a particular location. Bacterial migration under chemical gradient is one of the most studied areas in biomedical field. In this work we looked into how bacterial cells respond to sudden change in the microfluidic chemical environment. E. coli DH5 alpha cells were subjected to an attractant gradient (0.1 mM sorbitol - attractant to E.coli cells) and after 120 mM the same cells were exposed to an inhibitor (0.1 mM NiSO4) gradient in the same microfluidic device. Our studies revealed that when the E coli DH5 alpha cells were exposed to 0.1 mM sorbitol, they showed faster chemotaxis towards the attractant (0.1 mM sorbitol) and achieved steady state by 60 mM When we replaced 0.1 mM sorbitol with 0.1 mM NiSO4 in the device we found that that the E. coli DH5 alpha cells started responding to change in chemical environment within 10 mM and achieved steady state at the end of 60 mM This shows that the bacterial cells respond to change in local chemical environment is within few minutes.