Escherichia Coli Regulates Cell Division by Modulating Membrane Potential

Abstract

Indole is a very important biological molecule being produced by more than 85 Gram positive and Gram negative bacterial species, including Escherichia coli. Among its several physiological functions indole is shown to stop bacterial cell division when secreted in large quantities.Here we study the effect of indole on the electrical properties of the lipid membranes. Using electrophysiology, we show that the indole molecules are able to short-circuit lipid membranes. We also show that the rate of mitochondrial oxygen consumption measured in the presence of succinate increases when the indole concentration is titrated up. Therefore indole is capable of lowering the energetic barrier for ion permeation across lipid membranes. Since the bacterial cell division is strongly influenced by the ability of the cell to maintain a membrane potential(1) this is the first example of a bacterium using an ionophore to regulate the bacterial cell division. These findings have implications for our understanding of membrane biology, bacterial cell cycle control and potentially for the design of antibiotics that target the cell membrane.1. Strahl, H. & Hamoen, L.W. Membrane potential is important for bacterial cell division. Proceedings of the National Academy of Sciences 107, 12281-12286 (2010).