E. coli chemotaxis is information-limited

TL;DR

This study links information acquisition to chemotactic performance in E. coli, showing that bacteria operate near the theoretical information limit, which constrains their gradient-climbing speed.

Contribution

It establishes a quantitative relationship between information limits and behavioral performance in bacterial chemotaxis, introducing a theoretical maximum speed based on information rate.

Findings

E. coli use less than 1 bit of information for chemotaxis decisions

Cells perform near the theoretical information limit

Information limits can constrain organism behavior

Abstract

Organisms must acquire and use environmental information to guide their behaviors. However, it is unclear whether and how information quantitatively limits behavioral performance. Here, we relate information to behavioral performance in Escherichia coli chemotaxis. First, we derive a theoretical limit for the maximum achievable gradient-climbing speed given a cell's information acquisition rate. Next, we measure cells' gradient-climbing speeds and the rate of information acquisition by the chemotaxis pathway. We find that E. coli make behavioral decisions with much less than the 1 bit required to determine whether they are swimming up-gradient. However, they use this information efficiently, performing near the theoretical limit. Thus, information can limit organisms' performance, and sensory-motor pathways may have evolved to efficiently use information from the environment.