Team:NTU-Taida/Human practice/Safety

Common Concerns

The chloramphenicol and ampicillin resistance plasmids used in our project may have the danger to interact with the bacteria in the environment by horizontal gene transfer (HGT), which would enhance the virulence of other bacteria in the environment. But the chance of HGT between the engineered bacteria of our project and bacteria in the environment could be reduce to minimum for that our wet lab members had attended the pre-research training before we began the experiment of our project.

As for all the biobricks we use in our project, there is no evidence that they can harm the environment so far. But in the functional test stage, we have taken the samples from the patients in the hospital to test our biosensor, these samples may contain many unknown bacteria inside. But by following the proper experimental procedure, the risk of raising safety issue by these samples from hospital can be cut to none.

Biobrick Safety

In general case, the reason why people afraid of biochemical research is the danger from technique abused for incorrect goal. But even the direction of a research is right, the biomolecular products made in the progress or in the end of the experiments are not natural. They might have some effects on our environment for their similar property to the natural molecular if they were spread from the laboratories. Theses influences are hard to measure. That is why some standard have to be censored after a gene constructed, the safety examine. The most straight point to demonstrate are asking:

How easy do the products enter the natural environment? Would it be difficult to limit their spread? What effect do the construct do on species?

In our quorum sensing system, what we do is using E. coli as a signal sensor. That means: first, the E. coli transformed with the construct don’t need to enter any other creature. We want to make a platform, which gets sample in and makes signal out.

Only natural things like sputum, blood and so on serves as an intermediary. It is easy for this experiment to limit the E. coli in the laboratory. There is no way for bacteria to enter the environment. Second, for using bacteria as a sensor, gene expression in them is just receptors and signal reporter like GFP or luciferase. The construct we made won’t generate product modulating the cell. So, even the cells are spread into the environment and deliver to other bacteria, the biggest influence is some bacteria can take up some signal from other bacteria and make some XFP. Above all, the design we are going to make by synthetic biology has little safety concerns.

Biosafety Group

The most of our experiments were done in The First Core Laboratory of NTUCM and NTU Center of Genomic Medicine. The safety and health of these two institutions are supervised by Environmental Protection and Occupational Safety and Hygiene Unit of NTUCM. Before we starting our mission, our wet lab members had to be trained by this unit for two days. And we passed the exam after the course to be sure that all the rules about our work were well understood. In the process of our project, there were some related workers keeping watch over our wet lab operation. So, we can be sure that our experiments were under the biosafety rules of Environmental Protection and Occupational Safety and Hygiene Unit of NTUCM. http://www.mc.ntu.edu.tw/staff/safety/index-link/law.htm

Solution

To optimize the safe level of the bio-device, cell-free system may be a good choice. By stripping the cell membrane from the engineered cells, cell-free system ensures that those engineered cells won’t have the chance to infect human being and other lives on the earth, and the condition of cell-free system─such as pH, temperature and real substrate concentration─could be controlled more easily than the in vivo “intact-cell” system.

Furthermore, enzymatic reactions in cell-free systems without the barrier of cell membrane would have faster reaction rates than those in traditional systems “intact-cell” system. Therefore, though the progress of our project is still at the stage of in vivo “intact-cell” system, our ultimate goal is to construct a quorum-sensing-pattern biosensor chip in cell-free system. By this way, biosensor can be used safely and conveniently.

As for the part─or in the other word: biobricks, if the part itself is toxic and we are worry about that it will release into the environment an suicide switch, we can design a inducible proteasome/lysosome system, ensuring the toxic protein will be degraded to zero before it leaks from the broken cell. But those RNA and DNA which may cause risk in the environment are still a trouble to be solved.