Published on April 20th, 2011 | by Glenn Meyers1
Galvin Programs Bacteria; Gets Rid of Herbicides
The movie title might be rewritten as “The Ugly, The Bad, & the Good.”
Justin Gallivan, associate professor of biomolecular chemistry at Emory University, is busy developing new ways to reprogram bacteria to carry out some remarkable new tasks – instructing the E. Coli bacteria, for instance, to eat atrazine, a widely used herbicide that can cause considerable contamination of ground water.
Galvin, a 2010 Science and Public Leadership Fellow, reports at a PopTech presentation, that he finds himself “amazed by bacteria. You can get them to do almost anything,” he says in this 6:35 video.
According to Galvin, the key is to be able to turn the gene on and off, a task that be accomplished using a molecule called Riboswitch. “We want to be able to program the bacteria to send it after atrazine,” he stated on the PopTech blog. “Turns out we can do that.”
Galvin has written considerably about riboswitches – here in an RNA Society article, “The ability to encode riboswitches within translated regions as well as untranslated regions provides additional opportunities for creating new genetic control elements.”
For non-chemists, this article by Celia Arnaud in Chemical & Engineering News helps paint a picture about riboswitch functionality:
“The usual way to find riboswitches is to start with an RNA that tightly binds the target. ““You can imagine some RNAs that might bind atrazine very well but be incapable of undergoing a conformational change that allows you to get a change in gene expression,”” Gallivan says. Galvin and his coworkers screened a library of RNAs with moderate affinity for atrazine to find the best riboswitch. ““By doing in vivo selection, we can find switches that work the way we intend,”” he says.”
The result at Emory? Galvin’s team has rewired the bacteria to produce an enzyme that converts atrazine to hydroxyatrazine, which turns out not to act as a toxic herbicide.
As PopTech points out, Gallivan’s work integrating chemistry, biology and materials science “stands to transform the way we understand and utilize bacteria to improve our health and the environment.”