Biosafety

Working with genetic modified organisms requires an important focus on biosafety.
Due to the potentially hazardous nature of genetically modified organisms we have taken necessary steps to identify the possible mistakes that can occur. This involves taking precautions, one of which is strictly working with nonpathogenic bacteria[i].
We have been working in a class 1 laboratory and have followed all safety rules, needed to work in such an environment. In doing this we have also abided the local Danish laws[ii] on biosafety and read the specific guidelines for our institute.
One specific security guideline has been to reduce the risk of our biobrick giving the bacteria pathogenic properties, since this could pose an environmental problem.

In our efforts to comply with this guideline we have done the following:
The first safety measure we planned was a L-ramnose kill-switch. This would act as a safety measure in the final product. The consumer would be able to eat a small bag of L-ramnose (a sugar that the body can’t digest) which in turn would kill any genetically modified bacteria inhabiting the gut. It is relevant to note that the L-ramnose system would neither affect naturally occurring bacteria nor the human intestines.

We have located our genes in two different plasmids thereby allowing us to construct a dual toxin/antitoxin-system. The aim of this system is to prevent horizontal gene transfer by creating a cross-dependant toxin-antitoxin (TA) system.
As seen in the figure above, the cell can only survive by keeping both plasmids. In the case of horizontal gene transfer the receiving bacteria will lack the needed antitoxin for survival. For the same reasons, in case of a frameshift mutation knocking out one of the plasmids, the bacteria will also die. Both of these constructs require the antitoxin to be located downstream from the toxin.
Would any of your project ideas raise safety issues in terms of researcher safety, public safety, or environmental safety?

As seen in the figure above, the cell can only survive by keeping both plasmids. In the case of horizontal gene transfer the receiving bacteria will lack the needed antitoxin for survival. For the same reasons, in case of a frameshift mutation knocking out one of the plasmids, the bacteria will also die. Both of these constructs require the antitoxin to be located downstream from the toxin.

Do any of the new BioBrick parts (or devices) that you made this year raise any safety issues?

Our biobrick does not prove any obvious safety issues. As mentioned in the previous paragraph our construct has no evolutionary advantages. If any issues arise these will be documented in the registry.

What does your local biosafety group think about your project? And is there any local laws?

Our local biosafety group is called “Arbejdsmiljøgruppen”. They are responsible for biological and practical laboratory safety. During discussions with a group representative we concluded that, as long as we followed the class 1 laboratory guidelines no safety concerns were evident. Furthermore we investigated local laws concerning working with genetically modified organisms “The Order on Gene-technology and Working Environment[ii]“, which in turn correlates with rules laid down by the European Union in the ”Directive on the Contained Use of Genetically Modified Micro-organisms”.

Do you have any other ideas how to deal with safety issues that could be useful for future iGEM competitions?
How could parts, devices and systems be made even safer through biosafety engineering?

One of the safety measurements we are using it the paired, double toxin/anti-toxin kill-switch which we think should be a part of coming iGEM teams safety precautions.

[i]Bacteria: E. coli Strains: TOP10 and XL gold
[ii]link til https://www.retsinformation.dk/Forms/R0710.aspx?id=12325)