From 2010.igem.org

Project Overview

Project overview of E. lemming. The core idea of E. lemming is to control chemotaxis of E. coli by means of light! We'll realize this by hijacking and perturbing the tumbling / directed flagellar movement apparatus. By coupling directed flagellar movement regulating proteins to a novel synthetic light-sensitive spatial localization system, their activity can be controlled reversibly.

Molecular Mechanism

Molecular mechanism of E. lemming. A light-sensitive dimerizing complex fused to this regulating proteins at a spatially fixed location is induced by light pulses and therefore localization of the two molecules can be manipulated.

Information Processing

Information processing principle of E. lemming. Tumbling / directed flagellar movement rates are monitored by image processing algorithms, which are linked to the light-pulse generator. This means that ''E. coli'' tumbling is induced or suppressed simply by pressing a light switch! This synthetic network enables control of single E. coli cells.

E. lemming aims to modify the chemotaxis property of E.coli such that, instead of response to a chemical attractant or repellent, the bacterium responds to a light stimulus. Furthermore, this light sensitivity is used to control E.coli’s movement by deciding, at any given time, which type of motion the bacterium will adopt (tumbling or straight run). This leads to a controllable E.coli, which can move to a defined direction, as a result of the combination of tumbling and straight run. The bacteria in the experiment are imaged and, by image processing, the position of a single tracked cell is inferred. By activating a light switch, the user decides whether the bacterium should continue running or should change direction.