Red Green Blue (RGB) Color Bacteria Photography Strain


This tangible property is a strain of E.coli that responds to the visible light spectrum with applications as a synthetic biology research tool.

Problem Addressed

Cells have complex circuitry capable of sensing and responding to stimuli. Cellular engineering harnesses and refines intrinsic cellular circuitry to create cells capable of responding to pre-determined stimuli in useful ways. Most current cellular circuitry systems use inputs such as small molecules as inducers of signal output. These inventors built a cellular circuitry system to respond to red, green, and blue light inputs, thereby expanding the repertoire of potential inputs in synthetic biology systems.


This E.coli system responsive to red, green, and blue light requires four subsystems. Firstly, a ‘sensor array’ composed of proteins sensitive to red, green, or blue light is used to sense incoming light signals by activating or deactivating in response to incoming light signals. Next, a ‘circuit’ is required to invert the deactivating red and blue sensor proteins into induction signals. Thirdly, ‘actuators’ serve as resource allocators connecting the input signal to circuit outputs. To accomplish this, a split-phage RNA polymerase system is used in which a constitutively expressed core fragment is directed to three different promoters by binding to one of three different DNA binding fragments that are activated by red, green, or blue light. Finally, an ‘output’ is required, in which each color of light drives expression of a particular output. This is accomplished by controlling the expression of each output using the color-specific ‘actuator’ promoters. These inventors have successfully used this system to drive expression of outputs including metabolic enzymes, fluorescent proteins, or pigmentation proteins, and were able to successfully generate bacterial “photographs” by exposing the RGB E.coli strain to an image.


  • Light responsive cellular circuitry
  • Independent circuit outputs in response to red, green, or blue light
  • Expands repertoire of cellular circuitry inputs
  • All required components for system functionality integrated genomically and stable over generations