Student scientists have turned E coli bacteria in a Petri dish into a “living camera” which can produce high-resolution pictures.
The bacteria generated ghostlike images of people and objects imprinted on to their plate by a light projector.
Each of the genetically engineered bacterium used in the experiment acted like a pixel in a digital camera.
Bacteria in darker regions of the Petri dish produced a pigment which made them appear dark, while those in the lighted regions did not, and so appeared light. The result was a black and white image with a tremendously high resolution of up to 100 megapixels per square inch.
In comparison, high quality professional digital cameras have a resolution of about ten to 13 megapixels.
The team at the University of Texas designed the bacterial camera as part of a competition encouraging students to build simple biological machines.
The E coli bugs were initially genetically modified by giving them a light receptor gene.
The light receptor was then linked to a sensor in the bacteria that normally senses salt concentration. Instead, the GM bacteria were able to sense light.
For the experiment, a projector was used to shine images on to a Petri dish containing a jelly growth medium seeded with the light-sensitive bacteria. After 12 to 15 hours of exposure – the time it took for the bacteria to fill the dish – the projector was removed, leaving a living photograph.