Godány Martin, Khatri Bhavin S, Goldstein Richard A
Division of Infection & Immunity, University College London, London, United Kingdom.
The Francis Crick Institute, London, United Kingdom.
PLoS One. 2017 Jun 23;12(6):e0179111. doi: 10.1371/journal.pone.0179111. eCollection 2017.
Although the "adaptive" strategy used by Escherichia coli has dominated our understanding of bacterial chemotaxis, the environmental conditions under which this strategy emerged is still poorly understood. In this work, we study the performance of various chemotactic strategies under a range of stochastic time- and space-varying attractant distributions in silico. We describe a novel "speculator" response in which the bacterium compare the current attractant concentration to the long-term average; if it is higher then they tumble persistently, while if it is lower than the average, bacteria swim away in search of more favorable conditions. We demonstrate how this response explains the experimental behavior of aerobically-grown Rhodobacter sphaeroides and that under spatially complex but slowly-changing nutrient conditions the speculator response is as effective as the adaptive strategy of E. coli.
尽管大肠杆菌所采用的“适应性”策略主导了我们对细菌趋化性的理解，但这种策略出现时的环境条件仍知之甚少。在这项工作中，我们在计算机模拟中研究了一系列随机时空变化的引诱剂分布下各种趋化策略的性能。我们描述了一种新的“投机者”反应，即细菌将当前引诱剂浓度与长期平均值进行比较；如果浓度较高，它们就持续翻滚，而如果低于平均值，细菌就会游走以寻找更有利的条件。我们证明了这种反应如何解释好氧生长的球形红细菌的实验行为，以及在空间复杂但变化缓慢的营养条件下，投机者反应与大肠杆菌的适应性策略一样有效。
