Most biological organisms have the ability to sense their chemical environment and direct their motion toward attractants and away from repellents. This chemotactic behavior has been studied intensively in recent years. Among them, bacteria E. Coli. Chemotaxis is one of the best-studied systems in biology; it serves as an ideal model system in quantitative biology. In this talk, we will report our quantitative studies in recent years on E. Coli. chemotactic behavior under different spatiotemporal varying environments using both experimental and theoretical methods. In experiments, we developed microfluidic systems to accurately control the spatiotemporal patterns of bacteria environment, and observed the behavior of bacteria in the defined environment. The data collected the experiments was used to test the dynamics model of bacteria chemotaxis mechanism. New bacteria chemotactic behaviors were observed, and the new theoretical model was proposed.

References 

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X.J Zhu, G.W. Si, N.P. Deng, Qi Ouyang, T.L Wu, Z.R. He, L.L. Jiang, C.X. Luo, and Y.H Tu, Frequency-dependent Escherichia coli chemotaxis behavior，Phys. Rev. Lett 108, (2012) 128101.

Q.X. Cai, Z.J. Li, Qi Ouyang, C.X. Luo, V. Gordon, Singly Flagellated Pseudomonas aeruginosa Chemotaxes Efficiently by Unbiased Motor Regulation, mBio, 7 (2) (2016) E00013-16.

Z.J. Li, Q.X. Cai, X.Q. Zhang, G.W. Si, Qi Ouyang, C.X. Luo, Y.H. Tu, Barrier crossing in Escherichia Coli chemotaxis, Phys. Rev. Lett., 118 (2017) 098101.

X.Q. Zhang, G.W. Si, Y.M. Dong, K.Y Chen, Qi Ouyang, C.X. Luo, Y.H. Tu, Escape band in Eschrichia Coli chemotaxis in opposing attractant and nutrient gradients, PNAS, (2018) www.pnas.org/cgi/doi/10.1073/pnas/808200116.