Safety
Lab Safety
· Lab Safety Training
Before our team members are allowed to enter the lab, each of us must all take the lab safety training. The training includes how to use the machine in our lab properly, how to react correctly if there happens to be an emergency and how to protect ourselves during the experiments.
· Safety during the experiments
When we are doing the experiments, we can guarantee that:
- - Wearing lab-grown
- - Wearing lab gloves
- - Using the experimental machine properly
- - Deal with the waste in a proper manner
· Safety tutor
We have a safety tutor in our lab. He teaches us how to do the experiment safely, and he will watch us to make sure that we all behave in the right way. When we do something that is unsafe, he will point out and make sure that we won’t do it again.
Biobrick Safety
The Biobrick parts we have built have no safety issue according to our knowledge.
Project Related Material Safety
① Avermectins
· Environmental Safety
- - Can be decomposed easily by microorganism in soil
- - Sensitive to sun light
- - High selectivity: only have effects on a few certain pests including termites and cotton aphid
- - Complete safe to large mammals under recommended concentrations
- - See more in Extension Toxicology Network
· Application Safety
- - Completely safe to users under recommended dosage
- - Already existed mature industrial production system
- - Already have more than 3000 registered avermetin-related products in China, passing the security check of AQSIQ (State General Administration of the People’s Republic of China for Quality Supervision and Inspection and Quarantine)
② Toxic Proteins
Because the toxic proteins we use are recently discovered, few related researches can be found online. However, the proteins we use are pretty like bt protein, so we will use the data of bt protein to help us analyze.
· Environmental Safety
- - About 80% can be fast digested in soil or water in 20 days, but will be a little residue (10-20%)
- - Can be absorbed quickly and decomposed easily on the soil surface
- - Will NOT be reproduced in water. Will have some reproduction only in nutrient soil.
- - Non-toxic and non-pathogenic to birds, fish, and shrimp
- - High selectivity: little to no direct toxicity to non-target insects and other shelled invertebrates
- - No adverse effect to rats
- - Will NOT cause a disease outbreak among wild animals
- - Non-toxic to adults and infants
- - No contribution to the development of cancer
· Application Safety
- - Completely safe to users under recommended concentration
- - Will NOT be used or applied in the wild. Will be completely used in the house.
- - The bacterium are CNC-coated, having little to no leak of the toxic proteins consequently.
- - Completely no harm to adults and infants when users are behaved according to our instruction
Since the toxic proteins we choose are relative new, we cannot find their degradation period, degradation condition and more information related to safety. Thus we design a series of future experiments.
- -NMR will be used to detect proteins structure stability. Time gradient experiments will be conducted to test how fast the proteins will start to degrade
- -Proteins degradation rate will be tested under light, UV, high temperature and other conditions.
- -As the structure stability is being tested, proteins function will be tested. Termite will be fed with these toxic proteins and death condition will be used to evaluate the toxicity.
- -Toxic proteins will be mixed in other insects’ baits and fed to those insects to check the species specificity.
Experimental Safety
During the experiment, we worry that our gene modified bacterium would get out of the lab, thus we figured out several ways to make our bacterium safer.
① Inducible Promoter
In our plan, we shall build four constructs to express toxin proteins that help killing termites. In case that our bacterium get outside and leak the toxin into the environment, we use an inducible promoter in our constructs. Only when there is arabinose in the medium, can the promoter work as usual. There is no arabinose outside the lab, so our bacterium won’t leak the toxic protein.
② Kill Switch
Bacteria leakage remains a severe problem concerned with biosafety in iGEM projects. Here we designed a suicide switch to be on or off at a certain time with strict control to prevent the potential contamination. Moreover, this technique can be used to create an inexpensive and smooth recombinant protein release method other than traditional mechanical approaches (rough lysis) or chemical approaches (expensive).
With regard to this CidA-LrgA system and the BNU iGEM 2014 kill switch design, we designed our own kill switch as the figure below shows. When cultured with our IPTG-added medium, these bacteria would live as usual to function as a mini-factory to amplify plasmids or to produce plasmids for our use, whereas they would die due to the cell membrane lysis and genomic DNA release. Moreover, we put the lrgA gene under the control of a weak and constitutive promoter BBa_J23116 to in case of the leaky expression of the CidA to prevent cell lysis.
Device Safety & Social Safety
In our project, we designed a device aiming at better controlling and killng termites. This device is absolutely not allowed to be used outdoors, but is designed to be used in the house instead. After we designed the device, we are afraid that people might use it in a wrong way after they bought it. In order to avoid people wrongly operating our device, we also design an instruction of our device as below.
We plan to sell our device with the instruction attached to it, and we believe that our device would be safer with our well-designed instruction.
Furthermore, we considered the social safety of our whole project. According to the chart we show below, we considered every aspect to confirm that our project are safe under given conditions..
Reference
1. http://pmep.cce.cornell.edu/profiles/extoxnet/24d-captan/abamectin-ext.html
2. Bravo A, Soberón M. How to cope with insect resistance to Bt toxins?[J]. Trends in biotechnology, 2008, 26(10): 573-579.
3. Zhao R, Han R, Qiu X, et al. Cloning and heterologous expression of insecticidal-protein-encoding genes from Photorhabdus luminescens TT01 in Enterobacter cloacae for termite control[J]. Applied and environmental microbiology, 2008, 74(23): 7219-7226.
4. Meusch D, Gatsogiannis C, Efremov R G, et al. Mechanism of Tc toxin action revealed in molecular detail[J]. Nature, 2014, 508(7494): 61-65.
5. Gordon G D, Gordon J M. Device and method for termite detection and control: U.S. Patent 5,899,018[P]. 1999-5-4.
