Modeling polymorphic transformation of rotating bacterial flagella in a viscous fluid.
Modeling polymorphic transformation of rotating bacterial flagella in a viscous fluid.
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模拟粘性液体中旋转细菌鞭毛的多态性转化。
DOI：
10.1103/physreve.95.063106
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Peskin,CharlesS
中科院分区：
文献类型：
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作者：
Ko,William;Lim,Sookkyung;Lee,Wanho;Kim,Yongsam;Berg,HowardC;Peskin,CharlesS
附着在大肠杆菌和鼠伤寒沙门氏菌等细菌细胞体上的螺旋鞭毛使细胞能够在流体环境中游动。这些鞭毛能够进行多态性转化，因为它们呈现出不同的螺旋形状，这些螺旋形状在螺距、半径和手性方面不同。我们提出了一个数学模型的基尔霍夫棒理论描述的一个单一的鞭毛是沉浸在由斯托克斯方程的流体。我们进行数值模拟，以证明两种机制，多态性转换可以发生，在实验中观察到的。首先，我们考虑一个鞭毛丝连接到一个旋转电机，其中转换是由电机旋转方向的逆转触发的[L。Turner，J. Bacteriol. 182，2793（2000）10.1128/JB.182.10.2793-2801.2000]。然后我们考虑一端固定并浸入外部流体流中的细丝[H. Hotani，J. Mol. 156，791（1982）10.1016/0022-2836（82）90142-5]。螺旋鞭毛与粘性流体相互作用的详细动力学进行了讨论，并与实验和理论结果进行了比较。
The helical flagella that are attached to the cell body of bacteria such asEscherichia coliandSalmonella typhimuriumallow the cell to swim in a fluid environment. These flagella are capable of polymorphic transformation in that they take on various helical shapes that differ in helical pitch, radius, and chirality. We present a mathematical model of a single flagellum described by Kirchhoff rod theory that is immersed in a fluid governed by Stokes equations. We perform numerical simulations to demonstrate two mechanisms by which polymorphic transformation can occur, as observed in experiments. First, we consider a flagellar filament attached to a rotary motor in which transformations are triggered by a reversal of the direction of motor rotation [L. Turner , J. Bacteriol. 182, 2793 (2000)10.1128/JB.182.10.2793-2801.2000]. We then consider a filament that is fixed on one end and immersed in an external fluid flow [H. Hotani, J. Mol. Biol. 156, 791 (1982)10.1016/0022-2836(82)90142-5]. The detailed dynamics of the helical flagellum interacting with a viscous fluid is discussed and comparisons with experimental and theoretical results are provided.