Section 1 : Introduction

Safety has always been the most critical part of our project. We believe that a project is truly feasible and valuable only if it is safe enough. In order to ensure the safety of the project, we addressed all the risks from the laboratory to the production factory and completed safety training for all team members to demonstrate the responsibility of our team.

Section 2 : Project Safety

Hardware Safety

In our project design, we hope that our engineering bacteria can be applied in the industrial wastewater treatment process, so as to recycle the rare earth elements from wastewater as much as possible. Our special reactor can not only create a favorable environment for the engineering bacteria to express functional proteins, but also keep them completely in the reactor without being released.

Structure

Our reactor has a multi-layer filter structure, whose pore size can ensure that the silica solid would be kept in the reactor without leaking out. The tower structure can further ensure that the bacteria, entering the reactor with their liquid culture medium, will be firmly absorbed on the silica due to its fusion protein and will not flow to the downstream device along with the treated wastewater. The sealed reactor ensures that no functional material will flow out during the adsorbtion process.

Disposal

After several repeated cycles of flowing through the reactor, the bacteria culture medium will be directly imported into the high-temperature sterilization equipment to kill the engineering bacteria so that no living bacteria will enter the external environment. This treatment is common, safe and efficient in industrial production process.

For treated wastewater, our reactor exit equips with a sterilization chamber, where the wastewater will be sterilized by UV for a period of time before it goes to the next producing process.

This method can effectively prevent the engineering bacteria from being leaked and guarantee the safety of the working environment.

Microorganism Safety

All kinds of microorganisms used in our experiments are based on the White List and Risk Group classification of microorganisms permitted in iGEM, which can ensure their biosafety.

E. coli BL21(DE3) was selected as the final chassis organism. Through experimental verification, E. coli can well express the target protein that is able to perform the corresponding function. Since we do not adjust the heat resistance of E. coli, it can be easily killed by high temperature to ensure safety. That is easy to accomplish in the factory environment.

In the process of molecular experiment, we selected E. coli TOP10F '. This is a strain which can efficiently amplify vectors. All operations on it are carried out in the laboratory. The whole process obeys the experimental operation specifications and the lab safety rules.

Reagents Safety

The inducers involved in our experiment including IPTG, Cu²⁺, Tb³⁺ and other rare earth element ions.

IPTG as a commonly used inducer is safe.

Various kinds of metal ions exist in large quantities in wastewater, among which rare earth elements are absorbed by our bacteria and copper ions are also recovered in subsequent industrial processes. Metal ion inducers are contained in wastewater, so they are only present during production instead of being released into the environment or doing harm to human.

In addition, the fusion proteins expressed by our strain will only remain in the reactor. There is no way for them to contact with outside organisms.

In conclusion, our project would not cause any safety concern.

Working Environment Safety

Our project was designed to provide a biological means for the factory to recycle rare earth ions, so the application of our engineering bacteria will be fully implemented in an industrial production environment. Through field investigation of rare earth element mining sites, we learned that rare earth mining factories in China commonly use microorganisms to treat residual ammonia nitrogen in wastewater, so they have perfect sterilization and engineering bacteria sealing processes. Thanks to this, our strain is guaranteed to survive only in fermenters and reactors. Treated wastewater, used reactors and fermenters are strictly sterilized by trained staff and the process complies with the requirements of The Biosafety Law of the People's Republic of China.

Therefore, there is no safety problem of our project during the production process.

Section 3 : Lab Safety

Biosafety Laws in China

The Biosafety Law of the People's Republic of China was legislated at the 22nd meeting of the standing Committee of the 13th National People's Congress on October 17, 2020. All our work must obey the law before initiating.

Training

We trained our team members about the lab safety rules, and we invited Mengqu Ran as our safety officer. She taught us the specification of using experimental equipment and reminded us to pay attention to the safety of the laboratory.

Basic lab rules

We developed the using records of all the experimental equipment and dangerous drugs to ensure that laboratory materials are not abused or misused.

Safety for using heavy metal ions

Since our project is related to the recovery of rare earth elements, the experiment will inevitably involve the taking and preservation of heavy metal ions. For the drugs and other experimental materials containing heavy metals, the team members have done a good job of protection when using them: Placing the drugs in the fume hood, wearing masks, glasses, gloves and lab coats.