Safety has always been a major concern through our project, both in the experiments design and operations. We used two kinds of bacterium, which all belong to Enterobacteriaceae. One is Escherichia coli (DH5α) and the other is Enterobacter sp. FY-07. According to the official iGEM guidelines of Risk Groups, E. coli is categorized as Risk Group 1 organisms that “do not cause disease in healthy adult humans” when used properly. Enterobacter sp. FY-07 is categorized as Risk Group 2 organisms that “can cause disease in humans, but the disease is treatable or preventable”. The safety level of our lab is P2, which is safe enough to perform all our experiments. We highly valued the individual safety, environmental safety and biological safety.
1. Individual Safety and Environmental Safety
All the iGEMers in our project have taken safety training courses in our department experiment center. The safety training includes fire-fighting strategies, disposition of biochemical materials, proper usages of microwave oven and so on. All members have carefully read Safe Project Design, Safe Lab Work, Safe Shipment and other requirements proposed by iGEM Safety Committee. All members are required to wear nitrile gloves, masks, closed shoes in the lab to prevent potential threats of personal health. What’s more, we separate resting areas from experiment areas and confine eating and drinking in resting areas. Biological materials were not allowed to be taken outside the laboratory without sterilization and regular cleaning of the laboratory trash was arranged every day to maintain a clean and safe environment.
2. Biological Safety Concern Based on the Project
With the advent of synthetic biology, more and more genetically modified microorganisms are used for biomedical, industrial and environmental applications. To avoid diffusion of the genetically engineered Enterobacter sp. FY-07, we have come up with three strategies. I. Introduce the plasmid carrying xylose operon and lyase gene. The expression of the lyase is induced by xylose. II. Knock out the colicin gene in Enterobacter sp. FY-07 to eliminate the toxicity. The major concern is whether colicin knockout will affect the proliferation of bacterium. III. Add mf-lon ssrA tag into essential genes using CRISPR/Cas9 techniques. We can use biocontainment signal to control mf-Lon protease expression and block essential genes expression to kill bacterium upon loss of the biocontainment signal. As a matter of time, we only carried out the first strategy and successfully kill the bacterium upon applying the inducer.
3. Safe Shipping
We sent our BioBricks through the standard shipping process required by Igem headquarter.