Designer Microbes

Synthetic biologists are designing and manufacturing “complicated biological circuitry:” bacteria that blink on and off like Christmas tree lights, bacteria that reproduce photographic images, circuits of biological parts to sit in the body’s cells and guard against cancer, microbes that produce hydrogen for use as fuel.

17synb.xl.jpgLight-sensitive bacteria reproduce photographies.

“We’re talking about taking biology and building it for a specific purpose, rather than taking existing biology and adapting it,” Professor Jay D. Keasling said. “We don’t have to rely on what nature’s necessarily created.”

Also new is the desire to make the design of life forms more predictable, like the design of a bridge.

Drew Endy and colleagues at M.I.T. have started a Registry of Standard Biological Parts. The parts, called BioBricks, are strings of DNA that can perform certain functions like turning on a gene or causing a cell to light up.

Some scientists envision that biological engineers will one day sit at computers writing programs for cells, like software developers. But the code would be written in sequences of DNA.

Other scientists experimented with quorum sensing to control bacterial populations, by engineering the microbes to turn on a suicide gene if the concentration of the quorum-sensing chemical grew too high.

17blin.xl.jpgColony of bacteria engineered to blink on and off like Christmas tree lights

However, it might be difficult to make biological engineering as predictable as bridge construction. “There is no such thing as a standard component, because even a standard component works differently depending on the environment,” Professor France Arnold said. “The expectation that you can type in a sequence and can predict what a circuit will do is far from reality and always will be.”

The unpredictability could lead to safety risks. In addition, the same technology could be used to synthesize known pathogens based on their published DNA sequences. Scientists have already created a poliovirus from scratch and more recently recreated the 1918 pandemic flu virus.

“It’s quite clear this technology could be dangerous” if misapplied, Mr. Endy of M.I.T. warned.

Via The New York Times.