Team:MichiganState/Human Practices

Human Practices Silver

Human Practices Silver

MSU iGEM worked hard with both the scientific and surrounding community to explore many angles of our project. Collaboration with professionals across many scientific fields was of utmost importance to our work, as with many projects, so we made sure to meet with biochemists, microbiologists, engineers and more. We wanted to create the most practical, efficient, implementable and structurally sound project possible. Through extensive research, collaborations with other professors, seminars and other outreach events, we were able to collect vital information to help make our project more relevant to the world around us.

Why did we choose our project?

In the spring, Michigan State University hosted an environmental event, Challenging the Consumption Economy: Points of Intervention Tour. It emphasized the damaging impacts of consumer waste in an attempt to empower individuals to become a part of the collective solution. Members of the 2019 iGEM team realized they could not shy away from their duty to be apart of the solution. A panel of accredited environmentalists spoke about how they used their skills to improve the current state of our Earth. The panel was made up of many experts, including an artist using recycled materials, those working in public activism, a leader of the governmental recycling sector, and these activities inspired our undergraduate research. A point of intervention is where an intentional action can interrupt functioning systems and make way for change. The MSU 2019 iGEM realized that we needed to find our point of intervention. One large issue, global warming, soon became our focus as we know that if do not act soon, there could be irreversible damage done to the Earth. Overall, the goal for our project was to capture methane, a potent greenhouse gas, within landfills to reduce atmospheric methane. By reducing atmospheric methane, this, in turn, would help stop global temperatures from rising. In short, we wanted to do our part to help in the fight against global warming.

What concerns did we address?

Although the bacteria would likely be confined to the bioreactor a possible outcome with any synthetic biology project is the unwanted spread of your genes out into the world. To prevent this we worked to make a Type V toxin-antitoxin safety system. The system we are using is the ghoST toxin-antitoxin, meaning that the antitoxin (ghoS) forms an RNase that cuts up specific sequences in the toxin (ghoT). The ghoT toxin on its own creates a helical protein that integrates itself into lipid bilayers making them porous. This makes it impossible for the cell to build up a proton gradient, which results in little to no ATP being made and the organism's viability is ultimately impacted by this.

The way that the toxin-antitoxin system could be used to prevent the transfer of newly inserted genes into the environment first starts with the ghoS antitoxin being integrated into the organism's chromosome. Then by integrating the desired gene(s) into the organism with the ghoT toxin coding sequence on the same plasmid, the foreign genes are linked to a construct that confers a fitness disadvantage. The idea is that in the original organism the toxin will be rendered null by the antitoxin, but if the plasmid were to leave the organism and enter another organism then the new organism would not maintain the foreign genes or would die. This would stop the gene from being made or spreading outside its intended organism.

We understand the concern of genetically modified organisms, therefore we worked to stop the spread of unwanted genes out into the world.

Reaching above and beyond

To take the project to the next level required more knowledge about the place in which we wanted to implement our bioreactor. To see to what scale methane is being created and captured each day gave us perspective on how our bioreactor would have to function. There are many rules in place to ensure safety in landfills because they are dealing with numerous hazards every day. Understanding why said rules exist helped us when we returned to the lab and continued work on our project.