Biologists and bioengineers at the University of California, San Diego have created a “living neon sign” composed of millions of bacterial cells that periodically fluoresce in unison like blinking holiday bulbs.
Their achievement, detailed the journal
, involved attaching a fluorescent protein to the biological clocks of the bacteria, synchronizing the clocks of the thousands of bacteria within a colony, then synchronizing thousands of the blinking bacterial colonies to glow on and off in unison.
Part art and part bioengineering, the flashing bacterial signs show how researchers in the emerging field of synthetic biology can engineer living cells like machines. The flashy research could also lead to some exciting, real-life applications.
Using the same method used to create the flashing signs, the researchers engineered a simple bacterial sensor capable of detecting low levels of arsenic. In this biological sensor, decreases in the frequency of the oscillations of the cells’ blinking pattern indicate the presence and amount of the arsenic poison.
Because bacteria are sensitive to many kinds of environmental pollutants and organisms, the scientists believe this approach could be also used to design low cost bacterial biosensors capable of detecting an array of heavy metal pollutants and disease-causing organisms. And because the senor is composed of living organisms, it can respond to changes in the presence or amount of the toxins over time, unlike many chemical sensors.
“Because the bacteria respond in different ways to different concentrations by varying the frequency of their blinking pattern, they can provide a continual update on how dangerous a toxin or pathogen is at any one time,” said Jeff Hasty, a professor of biology and bioengineering at UC San Diego who headed the research team.
The development of the techniques used to make the sensor and the flashing display built on the work of scientists in the Division of Biological Sciences and School of Engineering, which they published in two previous
papers during the past four years.
Hasty said he believes that within five years, a small hand-held sensor could be developed that would take readings of the oscillations from the bacteria on disposable chips to determine the presence and concentrations of various toxic substances and disease-causing organisms.
to view a video of UCSD's flashing bacterial sign.