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

RUI：游动大肠杆菌产生的生物混合内的分子示踪剂扩散测量

• 批准号: 1205313
• 负责人: Daniel Spiegel
• 金额: $ 15.17万
• 依托单位: Trinity University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1205313&HistoricalAwards=false
• 关键词: RUI; Molecular; Tracer; Diffusion; Measurements

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.

在这个项目中，PI将与Trinity的本科生合作，采用激光诱导光栅实验技术，强迫瑞利散射（FRS），测量分子示踪剂在E.大肠杆菌浴，看看微米尺度上的扩散系数是否随细菌浓度增加。PI还将使用简单的傅立叶概念表明，如果示踪剂分子确实被游泳者驱动进入Lévy飞行，则FRS可以唯一地用于直接测量和量化Lévy偏离高斯扩散。这项关于极小雷诺数下分子输运的工作将大大有助于全面理解描述所有海洋生物的游泳者长度尺度和雷诺数范围内游泳者驱动的小分子通量。PI还将与一位Trinity微生物学家合作，开发一项本科生实验室实验，让学生调查大肠杆菌的感染方式。大肠杆菌已经进化到在趋化性过程中能超越分子扩散。