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Using bacteria to help prevent soil erosion – guest post from the iGEM Regional Champions

This is a guest post from a member of the iGEM competition team from Imperial College London. They recently won the iGEM regional championships and will be going to Boston in November to compete for the Worldwide Championships.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


This is a guest post from a member of the iGEM competition team from Imperial College London. They recently won the iGEM regional championships and will be going to Boston in November to compete for the Worldwide Championships. This post describes the work they did over the summer, and how they found the iGEM experience.

How was summer? We have no idea. We missed most of it while we were developing our iGEM competition project. No regrets though, as we were awarded the Grand Prize at the iGEM European Regional Jamboree, which made all of the hard work worth it.

For those that don’t know, iGEM stands for International Genetically Engineered Machine, and it’s a competition between teams of undergraduates from all over the world. The challenge is to develop a synthetic biology system, and present the results on a website of the team’s design and with a presentation and poster session. The teams then travel to a Regional Jamboree where they are weighed, measured and awarded prizes. The top teams win a place in the World Championship Jamboree in Boston, and a chance to win the grand prize: the coveted BioBrick Trophy.


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This past weekend, we flew out to Amsterdam to attend the European Jamboree hosted at VUAmsterdam, and I must say, it was spectacular! We got an amazing chance to meet with teams fromall over Europe and Africa and to talk about the projects they’re been working on. After a day of seeing so many awesome presentations, winning the Grand Prize was just gravy. Our project, AuxIn, was aimed at combating the spread of desertification by using bacteria to stimulate the growth of plant roots. The increased root mass helps to anchor the soil and prevent itfrom being eroded by wind or rain. By helping plants to establish strong roots, we can aid existing re-vegetation projects that are already being implemented across the globe.

The system is made up of three modules, which we named PhytoRoute, Auxin Xpress and GeneGuard. In PhytoRoute, we expressed a receptor that is sensitive to the chemicals released by plant roots. This plugs into the native chemotaxis machinery of E. coli and causes our bacteria to swim towards plant roots.

Auxin Xpress is our module for the secretion of auxin, a plant growth factor. To do this, we took the auxin producing pathway from the bacteria Pseudomonas savastanoi and expressed it in our E. coli cells, which we are using as a “chassis” for our system.

Our third module, Gene Guard, was born from the human practices surrounding our system. For our project to be implemented, we would need to release the bacteria into the environment. While we took advice from ecologists and other experts on the impact that this might have, there is still the ever-present fear of our genetic constructs spreading to native soil bacteria. So, in order to prevent horizontal gene transfer, we expressed a toxin on our AuxIn plasmid that will cause cell lysis in any bacterium that takes up the plasmid. Any bacterium except ours that is, as our bacteria express the antitoxin from their genome, which is unable to be passed to other bacteria.

Of course, this is merely a taste of the work we’ve been doing; you can see it in more detail at our wiki.

To be honest, I don’t think the news has completely sunk in yet, but I know that I am never going to forget the moment when our name was announced and the rest of the team all jumped up in celebration. Still, that wasn’t the best part of the iGEM experience. This summer was one of the best of my life, and it was all thanks to my teammates and our advisors for making it fun. To any undergraduates reading this: Do iGEM. Even if you have to start your own team, do it. You’ll love every minute of it.

Not being the sort to rest on our laurels, however, we’re currently heading back into the lab to prepare for the World Championship Jamboree in November. It’s going to be a little more difficult now that we all have lecture courses starting, so we’re going to have to surrender what little remains of our free time. You can see how we get on at our wiki or by following us on Twitter, @ImperialiGEM11

Wish us luck!

About S.E. Gould

A biochemist with a love of microbiology, the Lab Rat enjoys exploring, reading about and writing about bacteria. Having finally managed to tear herself away from university, she now works for a small company in Cambridge where she turns data into manageable words and awesome graphs.

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