The Range of Attractant Concentrations for Bacterial Chemotaxis and the Threshold and Size of Response over This Range
The Range of Attractant Concentrations for Bacterial Chemotaxis and the Threshold and Size of Response over This Range
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细菌趋化性的引诱剂浓度范围以及在此范围内的响应阈值和大小
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
J. Adler
中科院分区：
文献类型：
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作者：
R. Mesibov;G. Ordal;J. Adler
将引诱剂加入到细菌悬浮液中（引诱剂的背景浓度），然后将这些细菌暴露于毛细管中更高浓度的引诱剂。趋化性是通过确定有多少细菌聚集在毛细血管中来测量的。趋化性的响应范围介于阈值浓度和饱和浓度之间。该范围的宽度对于由不同化学感受器检测到的引诱物是不同的。被同一种化学感受器检测到的引诱物，其反应范围可能大不相同。在响应范围的中心（在对数标度上），细菌对浓度的类似分数增加给出类似大小的响应，即它们对引诱剂浓度的比率作出响应，但响应峰值在范围的中心。不同的化学感受器检测到的引诱剂的响应的大小是不同的。对于可检测的响应，由一些化学感受器检测到的引诱物比由其他化学感受器检测到的引诱物需要更小的引诱物浓度增加。虽然数据是不充分的，它似乎可以观察到韦伯定律在很宽的浓度范围内的一些引诱剂，但不为其他。在附录中，我们的目的是解释一些这些结果的相互作用的引诱剂与其化学感受器根据法律的质量行动。
Attractant was added to a suspension of bacteria (the background concentration of attractant) and then these bacteria were exposed to a yet higher concentration of attractant in a capillary. Chemotaxis was measured by determining how many bacteria accumulated in the capillary. The response range for chemotaxis lies between the threshold concentration and the saturating concentration. The breadth of this range is different for attractants detected by different chemoreceptors. Attractants detected by the same chemoreceptor can have their response ranges in widely different places. Over the center of the response range (on a logarithmic scale), bacteria give similar sized responses to similar fractional increases of concentration, i.e. they respond to ratios of attractant concentration, but the response peaks at the center of the range. The size of the response is different for attractants detected by different chemoreceptors. For a detectable response, a smaller increase in attractant concentration is needed for attractants detected by some chemoreceptors than for attractants detected by others. Although the data are inadequate, it appears that the Weber law may be observed over a wide range of concentrations for some attractants but not for others. In the Appendix we aim to explain some of these results in terms of the interaction of an attractant with its chemoreceptor according to the law of mass action.