Swimming patterns and dynamics of simulated Escherichia coli bacteria.
Swimming patterns and dynamics of simulated Escherichia coli bacteria.
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模拟大肠杆菌的游泳模式和动力学。
DOI：
10.1098/rsif.2008.0397
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Bray,Dennis
中科院分区：
文献类型：
--
作者：
Zonia,Laura;Bray,Dennis
利用大肠杆菌趋化性的空间和时间模拟研究了野生型和突变型细菌在矩形竞技场内对化学引诱剂梯度的游动模式。游泳动力学分析在长时间序列的相空间轨迹，功率谱和分形维数（FD）的估计。细胞运动在相空间中表现出复杂的轨迹，这是由于多个吸引子的相互作用，捕获了运行和翻滚。负责适应的酶（CheR和切布）的缺失限制了细菌在没有梯度的情况下游泳的模式。在梯度的存在下，有一个强烈的增加轨迹所产生的运行和衰减所产生的翻滚。对于缺乏CheY的突变体也观察到了类似的动力学，这些突变体无法翻滚。CheR、切布和CheY的缺失也引起趋化性光谱频率的显著变化。重标极差分析和FD估计表明，野生型细菌显示分数布朗运动的特征与过去和未来事件之间的正相关。这些结果揭示了细菌游泳动力学的基本顺序，这使得趋化搜索策略符合分形行走。
A spatially and temporally realistic simulation ofEscherichia colichemotaxis was used to investigate the swimming patterns of wild-type and mutant bacteria within a rectangular arena in response to chemoattractant gradients. Swimming dynamics were analysed during long time series with phase-space trajectories, power spectra and estimations of fractal dimensions (FDs). Cell movement displayed complex trajectories in the phase space owing to interaction of multiple attractors that captured runs and tumbles. Deletion of enzymes responsible for adaptation (CheR and CheB) restricted the pattern of bacterial swimming in the absence of a gradient. In the presence of a gradient, there was a strong increase in trajectories arising from runs and attenuation of those arising from tumbles. Similar dynamics were observed for mutants lacking CheY, which are unable to tumble. The deletion of CheR, CheB and CheY also caused significant shifts in chemotaxis spectral frequencies. Rescaled range analysis and estimation of FD suggest that wild-type bacteria display characteristics of fractional Brownian motion with positive correlation between past and future events. These results reveal an underlying order in bacterial swimming dynamics, which enables a chemotactic search strategy conforming to a fractal walk.