Physical mechanisms for chemotactic pattern formation by bacteria
Physical mechanisms for chemotactic pattern formation by bacteria
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DOI：
10.1016/s0006-3495(98)77880-4
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发表时间：
1998-04-01
影响因子：
3.4
通讯作者：
Budrene, EO
中科院分区：
文献类型：
--
作者：
Brenner, MP;Levitov, LS;Budrene, EO
本文阐述了大肠杆菌在分泌引诱剂存在下形成趋化模式的理论。在化学中性背景下，通过化学引诱物信号，细菌组织成群环和聚集体。分析调用只有那些物理过程，都是合理的已知的生物化学和必要的和足够的群环迁移和聚集体的形成。在没有外部化学引诱物梯度的情况下，群环迁移。环运动是由产生引诱剂所必需的底物的耗尽引起的。提出了几个标度律，并证明与实验数据是一致的。聚集体的形成对应于细菌密度在一点发散的有限时间奇点。导致聚集体形成的群环的不稳定性通过类似于聚集体形成本身的机制发生：当群环的质量密度超过阈值时，环呈圆柱形塌陷，然后不稳定成聚集体。这一系列事件在理论模型和实验中都得到了证明。
This paper formulates a theory for chemotactic pattern formation by the bacteria Escherichia coli in the presence of excreted attractant. In a chemotactically neutral background, through chemoattractant signaling, the bacteria organize into swarm rings and aggregates. The analysis invokes only those physical processes that are both justifiable by known biochemistry and necessary and sufficient for swarm ring migration and aggregate formation. Swarm rings migrate in the absence of an external chemoattractant gradient. The ring motion is caused by the depletion of a substrate that is necessary to produce attractant. Several scaling laws are proposed and are demonstrated to be consistent with experimental data. Aggregate formation corresponds to finite time singularities in which the bacterial density diverges at a point. Instabilities of swarm rings leading to aggregate formation occur via a mechanism similar to aggregate formation itself: when the mass density of the swarm ring exceeds a threshold, the ring collapses cylindrically and then destabilizes into aggregates. This sequence of events is demonstrated both in the theoretical model and in the experiments.