Team:Rheda Bielefeld/Biosafety

Biosafety



Biosafety

Before we dive into the reasons of writing this abstract I should explain what biosafety stands for. In the paper "Safety, security, and serving the public interest in synthetic biology" Gronvall defines biosafety: "Biosafety involves the safe handling and containment of infectious microorganisms and hazardous biological materials, and biosecurity pertains to the threats posed to human and animal health, the environment, and the economy by deliberate misuse or release of microbiological agents and toxins." (Gronvall, 2018)

Why is biosafety so important in synthetic biology, especially in a competition like iGEM?

In synthetic biology the organisms e.g. Escherichia Coli (E. coli) are being genetically modified to produce or dismantle various things. But if only one genetically modified organism escapes the laboratory it can harm the environment and the humans. Through safety measures including a kill switch or making them dependent on a substance which they can't produce themselves but are needed for their survival it is possible to contain them in a laboratory setting.

As an example, we use our project. In our project we used PCR-based methods to break the pollens exine and get their DNA. For that we use E. coli by implementing an enzyme that dismantles cellulose and pectin, of which the plant cell hull is based on. An in this way altered E. coli bacterium has the ability to dismantle cellulose, and with that ability it could wreak havoc in the environment because the cell wall of green plants and many algae are made out of cellulose. Therefore we wanted to use a kill switch for example which releases a toxin and thus killing them. A different way would be making them dependent through a substance which they usually could produce by themselves but was cut out to hinder them producing it and so making them dependent on this substance because they need it for their basic functions.

What is a kill switch ?

Basically, it is an if & else switch.
If an activator, which is defined in the kill switch, like ultraviolet hits the bacteria, the kill switch activates and destroys the bacteria from the inside. As explained in the previous paragraph the kill switch is there to prevent an outbreak and there are many ways to use a kill switch. One example is a kill switch by Team Wageningen UR 2014 (1), which has two toxins called Kid and Zeta and two antitoxins called Kis and Epsilon against those toxins. But the toxin and its antitoxin are on separate plasmids and so created an interdependent system. If the production of only one antigen, which needs a specific substance to be produced, stops the cell will die or one plasmid gets transferred to a wildtype cell, the antitoxin for the toxin on the plasmid is not present, thus killing the recipient.