Rotational-translational models for interpretation of quasi-elastic light scattering spectra of motile bacteria.
Rotational-translational models for interpretation of quasi-elastic light scattering spectra of motile bacteria.
复制标题
用于解释运动细菌的准弹性光散射光谱的旋转平移模型。
作者：
M. Holz;S. H. Chen
准弹性光散射是研究液体悬浮液中运动细菌动态行为的有力工具。之前我们提出了一个椭圆体结构模型来解释大肠杆菌的直线运动。在本文中，我们扩展了结构模型，将旋转运动叠加在质心的平移运动上。给出了一个通用公式，通过该公式可以计算结构化颗粒的任何旋转-平移运动的光散射光谱。针对围绕平均运动方向的平面摆动运动、纯旋转和螺旋旋转三种旋转运动进行了具体计算。在所有三种情况下都观察到与直线运动相比，散射场相关函数进一步变窄。最后，我们将螺旋旋转模型与之前的大肠杆菌实验结果进行比较，发现比直线运动模型有实质性的改进。
Quasi-elastic light scattering is a powerful tool for studying dynamic behavior of motile bacteria in liquid suspension. Previously we proposed an ellipsoidal structural model to account for the straight line motion of E. coli bacteria. We have in this article extended our structural model to include rotational motions superimposed on the translational motion of the center of mass. A general formulation is given by which the light scattering spectrum of any rotational-translational motion of a structured particle can be calculated. Specific calculations are carried out for three types of rotational motions, namely, planar wiggling motion, pure rotation, and helical rotation, around the average direction of motion. Further narrowing of the scattered field correlation function as compared with that of the straight line motion is observed in all three cases. We finally compare the helical rotation model with our previous experimental results for E. coli and find a substantial improvement over that of the straight line motion model.