Aetiology

I mentioned a real "microbial machine" in this post last month. Now, they're appearing as living photographs:

Researchers at the University of California, San Francisco and the University of Texas announced in the journal Nature that they had created photographs of themselves by programming the bacteria — — best known for outbreaks of food poisoning — to make pictures in much the same way Kodak film produces images.

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Voigt and colleagues took from algae light-sensitive genes that emit black compounds and spliced them into a batch of E. coli bacteria. The organisms were then spread on a petri dish that resembles a cookie sheet and placed in an incubator. A high-powered projector cast photographic images of the researchers through a hole on top of the incubator, exposing some of the bacteria to light.

The result: Ghostly images like traditional black-and-white photographs of the researchers responsible for the invention, at a resolution Voigt said was about 100 megapixels, or 10 times sharper than high-end printers.

Synthetic biology: Engineering Escherichia coli to see light

Anselm Levskaya1, Aaron A. Chevalier, Jeffrey J. Tabor, Zachary Booth Simpson, Laura A. Lavery, Matthew Levy, Eric A. Davidson, Alexander Scouras, Andrew D. Ellington, Edward M. Marcotte and Christopher A. Voigt

Abstract:We have designed a bacterial system that is switched between different states by red light. The system consists of a synthetic sensor kinase that allows a lawn of bacteria to function as a biological film, such that the projection of a pattern of light on to the bacteria produces a high-definition (about 100 megapixels per square inch), two-dimensional chemical image. This spatial control of bacterial gene expression could be used to 'print' complex biological materials, for example, and to investigate signalling pathways through precise spatial and temporal control of their phosphorylation steps.