Genetically engineering e. coli bacteria to do cool things is the latest craze in the science world. The latest, sci-fiesque case in point: Biologists and bioengineers at UC San Diego have created a living neon sign made of e. coli bacteria that will glow based on triggered reactions, completely in unison.
Bacteria communicate by a method known as quorum sensing, which means that they actually pass molecules between them to coordinate and trigger behavior. With knowledge of how to manipulate those triggers, the bacteria can be made to react in predictable ways. In this case, some genetic engineering caused that reaction to be a fluorescent glow by adding a particular protein to the bacteria’s biological clock. That in itself is an amazing accomplishment, but quorum sensing isn’t a large or fast enough process to work quickly on millions of bacteria together, so microfluidic chips (below right) were designed to harness the localized trigger and broadcast it to the plethora of shared colonies existing on the chip.
In this fashion sensor displays can be made to glow in the presence of engineered triggers like toxic substances or disease causing organisms. Seem like science fiction? It should. Biotechnology such as living sensors are the building blocks of scientific advances in a number of fields culminating into artificial life, or at least hybrid machines with living, breathing parts. Wearable sensors or material that react to diverse stimuli are completely within reason, though the idea of wearing bacteria may sound a touch odd to most.
The colonies can also be used to monitor sustained effects, where most sensor equipment currently used is one-shot only. E. coli is easy bred in a lab and can be commercially created, so it’s a completely economically viable solution, too.
Each of the bacteria cells on the microfluidic chip is called a “biopixel,” much like the pixels on a computer or television screen. Each biopixel can be turned “on” or “off” via the triggers to create an image on the sensor, so the diverse potential of this achievement shouldn’t be understated. It’s not a stretch to imagine functional application of this technology to other sectors of science.
The future of sensing technology is going to be in living sensors that are manipulated by science to produce wanted effects. Expect to see throw-away bacteria powering displays and other equipment in the near future. We’re surrounded by (and chalk full of) bacteria every moment of our lives, it’s only fair to put some of them to work for us, right?
