Las Vegas probably isn’t going to swap out its light bulbs anytime soon, but if it wants to, it has a new option that’s a little more exciting than just screwing in a CFL. Scientists have created glowing bacteria that blink on and off in unison when exposed to chemicals ranging from air pollution to poisons.
It’s a tour de force of synthetic biology in which researchers have engineered the genetic code and behavior of organisms to respond to specific triggers in the environment. The findings, published in Nature, may lead to life-altering applications such as a ubiquitous bacterial sensors that detect even tiny concentrations of chemicals.
Previous attempts to create such biological sensors were disappointing because coordinating the behavior of so many cells in thousands of different colonies proved difficult. Researchers from UC San Diego overcame these difficulties by laying out millions of E. coli bacteria on a specially designed chip. To ensure every cell was in sync, the scientists exploited two powerful pathways microbes use to communicate: small transmitter molecules between cells in close proximity–known as quorum sensing–and gasses emitted by different bacterial groupings that coordinate actions between separate colonies (of which there are thousands in an area the size of your thumb). When placed on these special chips, the researchers were able to trigger a synchronized blinking pattern among millions of bacterial cells, and among as many as 50 to 60 million on the larger chips.
“This development illustrates how basic, quantitative knowledge of cellular circuitry can be applied to the new discipline of synthetic biology,” said James Anderson at the National Institutes of Health’s National Institute of General Medical Sciences, in a university statement.
The new chips can be used for the production of biochemicals, tissue engineering, and biosensors that continually monitor the environment, rather than offer a one-off test that must be replaced every time new readings are needed. Besides the obvious practical uses, the sensors offer good aesthetics: The new “biopixels” come in beautiful shades of blue.