RUI: Molecular Tracer Diffusion Measurements Within the Biomixing Generated by Swimming E. Coli

点击翻译按钮获取中文摘要

In this project the PI will work with Trinity undergraduates to employ the laser-induced-grating experimental technique, forced Rayleigh scattering (FRS), for measurements of molecular-tracer diffusion coefficients within E. coli baths to see if the diffusion coefficients on micron length scales increase with the bacterial concentration. The PI will also show using simple Fourier concepts that FRS can be uniquely employed to directly measure and quantify Lévy deviations from Gaussian diffusion if the tracer molecules are indeed driven into Lévy flights by the swimmers. This work on molecular transport at the very small Reynolds number will help significantly in a complete comprehension of swimmer-driven small-molecule flux over ranges of swimmer length scales and Reynolds numbers that describe all marine organisms. The PI will also collaborate with a Trinity microbiologist to develop an undergraduate laboratory experiment in which students investigate the manner in which E. coli have evolved so that they outrun molecular diffusion during chemotaxis.