Understanding the hydrodynamic interaction among flagella of E. coli using the immersed boundary method combined with the Kirchhoff rod theory

利用浸入边界法结合基尔霍夫杆理论了解大肠杆菌鞭毛之间的水动力相互作用

• 批准号: 0815751
• 负责人: Sookkyung Lim
• 金额: $ 14.49万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0815751&HistoricalAwards=false
• 关键词: Understanding; hydrodynamic; interaction; among; flagella

A new mathematical model is developed to understand the swimming mechanism of bacteria such as Escherichia coli. The bacterium E. coli is a single-celled organism which swims in a viscous fluid by rotating its helical flagellar filaments. Two successive motions are involved in the cell motility: Runs (straight swimming propelled by flagellar bundling) and tumbles (random reorientation by interspersing flagella). This project will focus on the study of the hydrodynamic interaction among flagella and flagellar filament shapes that arise through polymorphic transformations?local changes in helical wavelength, helical diameter, and handedness?during swimming. A generalized version of the immersed boundary method combined with the unconstrained Kirchhoff rod theory is used to study biological fluid mechanics in the bacterium. A new feature of this method is that the interaction of the immersed boundary with the fluid now involves not only translation of the immersed boundary points at the local fluid velocity, but also rotation of the associated triads at the local fluid angular velocity. This method will find numerous applications in biological fluid dynamics, where filamentous structures interact with a viscous fluid. Examples include the supercoiling of DNA during transcription and replication and protein folding. In addition, one of the challenges in nanotechnology is to develop machines at the nanoscale which can be used in the treatment of disease. Understanding swimming mechanism by means of rotary motors will help to create a nanomachine, operated by self-propelled biomolecular nano motors, that could be used for drug delivery inside the body. Furthermore, such interdisciplinary projects give rise to problems and activities that can be used to attract students to science through the investigator's work with the Women in Science and Engineering program (WISE) at her university.

一个新的数学模型被开发来理解细菌如大肠杆菌的游动机制。 细菌E.大肠杆菌是一种单细胞生物体，它通过旋转其螺旋鞭毛丝在粘性流体中游动。 两个连续的运动涉及细胞运动：游动（由鞭毛捆绑推动的直线游泳）和翻滚（由散布鞭毛的随机重新定向）。 本计画将著重于研究鞭毛与鞭毛丝形状之间的流体动力相互作用，而鞭毛丝的形状是经由多形转变而产生的。螺旋波长、螺旋直径和旋向性的局部变化？在游泳时。 将广义浸入边界法与无约束基尔霍夫杆理论相结合，研究了细菌中的生物流体力学。 该方法的一个新特点是，浸没边界与流体的相互作用现在不仅涉及浸没边界点在局部流体速度下的平移，而且还涉及相关三元组在局部流体角速度下的旋转。 这种方法将在生物流体动力学中找到许多应用，其中丝状结构与粘性流体相互作用。 例子包括转录和复制过程中DNA的超螺旋和蛋白质折叠。 此外，纳米技术的挑战之一是开发可用于治疗疾病的纳米级机器。 通过旋转马达了解游泳机制将有助于创造一种由自推进生物分子纳米马达操作的纳米机器，该机器可用于体内药物输送。 此外，这些跨学科项目产生的问题和活动可通过调查员在她所在大学的妇女参与科学和工程方案的工作吸引学生学习科学。