But before this technology can be realistically implemented, scientists and engineers need to be able to control a number of variables associated with the film, such as how much of the film grows in the reactor, how long it must remain in the reactor and in what proportions different biofilms coexist within the reactor.
That's where Wood and Jayaraman's research comes into play.
"Never before has a group discovered proteins that make biofilms disperse and then used them in a synthetic circuit," Wood said. "We took advantage of the fact that cells talk to each other. We took another bacterium's signal and had E. coli make it because it doesn't normally make it. We also inserted the receiving mechanism in E. coli. And we were responsible for putting an 'on-off switch' within the bacteria because we wanted this signal broadcast continuously."
By genetically inserting a foreign chemical signal from another bacterium Pseudomonas aeruginosa into E. coli, the research team was able to force one group of E. coli to continuously emit this chemical signal. The group then inserted this group of bacteria into an environment where a biofilm was present. That existing biofilm was also genetically modified to receive the chemical signal. Once the signal was received, Wood explains, the bacteria within the biofilm responded by breaking apart and leaving the environment, effectively dispersing the biofilm.
"We developed novel miniature models of biofilm reactors where we can exquisitely control which bacterial species is colonizing, for what duration, and to which signals it is exposed to during growth," Jayaraman explained. "Apart from enabling us to control th
|Contact: Ryan Garcia|
Texas A&M University