Collaborative research: The effects of fluid flow on flagellar mechanics and microbial motility

合作研究：流体流动对鞭毛力学和微生物运动的影响

基本信息

批准号：
1700961
负责人：
Arezoo Ardekani
金额：
$ 25.57万
依托单位：
Purdue University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-15 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1700961&HistoricalAwards=false
关键词：
Collaborative research effects fluid flow

项目摘要

Swimming cells including plankton, sperm, and bacteria play a crucial role in the environment, in human health, and in industrial systems. These cells breakdown pollutants and waste products, transport DNA during reproduction, and provide a promising source of renewable biofuel. Swimming is a fundamental strategy of many single cells, which use hair-like flagella to swim toward nutrients and mates, and away from toxins. However, sometimes cells must ?swim upstream?, and overcome ubiquitous currents and ambient flow of the fluid in which they swim. The role of fluid flow on flagellar mechanics and the spontaneous movement of cells is not well understood. This research project is studying how fluid flow modifies flagellar motion through a combination of direct imaging and mathematical modeling. This work has broad implications for the development of medical devices and medical treatments, the improvement of bioreactors and biofuel production efficiency, and understanding ecosystem dynamics in oceans, lakes, and groundwater. Ambient velocity gradients are known to lead to strong accumulations of cells in flow regions characterized by high shear rates, and the nature of the cell accumulation is strongly dependent on cell motility, shape, and flagellation. This research project uses a synergistic approach incorporating microfluidics and high-speed imaging with state-of-the-art numerical simulations to: (1) Determine the hydrodynamic effects of flow on the flagellar beating of single, tethered cells; (2) Determine how externally-imposed flow affects the hydrodynamics and transport of free swimming cells through flagellar deformation; (3) Establish how flagellar mechanics couple to collective, self-generated flows in dense suspensions of active cells. This project is opening a new, rich research direction in single cell hydrodynamics, where the role of fluid flow has been largely neglected, despite its many implications for biology, ecology and medicine. The researchers on this project are establishing unique empirical data sets and numerical models that map the effects of external fluid forces on active force generation inside flagella, and such information will be an asset to microbiologists, ecologists, and biophysicists interested in modeling cell locomotion. The project is also extending existing methods to quantify flow-structure interactions by characterizing the deformation of flexible appendages having internal force generation, i.e. flagella. Graduate and undergraduate students supported by this project are receiving unique interdisciplinary training in fluid dynamics and microbial biophysics. A hands-on high-speed imaging interactive exhibit at the Indiana State Museum is incorporating these research themes, which will reach middle school students who attend the museum.

包括浮游生物，精子和细菌在内的游泳细胞在环境，人类健康和工业系统中起着至关重要的作用。这些细胞分解污染物和废物产物，在繁殖过程中运输DNA，并提供有希望的可再生生物燃料来源。游泳是许多单个单元的基本策略，它们使用类似头发的鞭毛来朝着营养和伴侣游泳，并远离毒素。但是，有时必须在上游游泳，并克服无处不在的电流和游泳的液体的环境流动。流体流在鞭毛力学和细胞自发运动中的作用尚不清楚。该研究项目正在研究流体流如何通过直接成像和数学建模的组合来修饰鞭毛运动。这项工作对医疗设备和医疗治疗的开发，生物反应器和生物燃料生产效率的改善以及了解海洋，湖泊和地下水的生态系统动态具有广泛的影响。已知环境速度梯度会导致以高剪切速率为特征的流动区域中的细胞积累，并且细胞积累的性质在很大程度上取决于细胞的运动，形状和鞭毛。该研究项目采用一种协同方法，该方法结合了微流体和高速成像以及最新的数值模拟，以：（1）确定流动动力学对单个束缚细胞的鞭毛跳动的流体动力效应；（2）确定外部施加的流程如何通过鞭毛变形影响自由游泳细胞的流体动力和运输；（3）建立如何在活性细胞密集的悬浮液中鞭毛夫妇夫妇如何进行集体，自我生成的流动。该项目在单细胞流体动力学中打开了一个新的，丰富的研究方向，尽管它对生物学，生态学和医学有许多影响，但流体流的作用已在很大程度上被忽略了。该项目的研究人员正在建立独特的经验数据集和数值模型，以绘制外部流体力对鞭毛内部发电的影响，这些信息将成为微生物学家，生态学家和生物物理学家的资产，感兴趣的是对细胞机构进行建模的资产。该项目还通过表征具有内部力量产生的柔性附件的变形，即鞭毛，扩展了现有方法来量化流量结构相互作用。该项目支持的研究生和本科生正在接受流体动力学和微生物生物物理学方面的独特跨学科培训。印第安纳州立博物馆的动手高速成像互动展览正在纳入这些研究主题，该研究将吸引参加博物馆的中学生。