Safe Project Design

Saccharomyces cerevisiae is not only an ideal chassis for nootkatone production, but also is a eukaryote which is friendly to genes biosafety. Besides, our strains will be used in factories, where they will function in fermentation cylinders. Thus, the possibility of horizontal transfer is substantially reduced and the modified genes in our strains will be unlikely to contaminate the natural strains. Not only S. cerevisiae but also the enzymes and products expressed by Saccharomyces cerevisiae are safe in our project.

As we hope that the modified strains can achieve high yield in the factory environment, the economic benefit is a very important point to consider. It can be seen from the above that the chassis and parts we use are harmless to the human body and the environment. It is a pity that the kill switches and other incorporated biocontainment strategies will impose a burden on the modified strains, and auxotrophy species will need additional growth factors which will increase the cost. The other reason we did not use the incorporated biocontainment strategies for our strains is that our modified strains may be used in the factory, where the possibility of escape of strains is low. In the laboratory, our members have also received comprehensive experimental training to reduce the possibility of leakage in the laboratory as much as possible.

If the project goes ahead, our products will be released outside the laboratory as mosquito repellents after being approved, but it does not include our modified strains. It further ensures that our engineered strains do not lead to uncontrollable risks.

Safe Lab Work

Before we enter the laboratory to do the experiment, we will receive the training from the safety staff of our school. Each of us will receive a laboratory safety manual, which contains the proper dress code in the laboratory, the management of chemicals and the instructions for the use of dangerous equipment, etc. After that, the senior students of our laboratory will introduce more detailed safety regulations to us, such as handling of hazardous waste, conventional sterilization methods and so on. Besides, the instruments in our laboratory are all posted with the safety matters that need to pay attention to when using the instrument, so the operation error of the instrument can be substantially reduced.

The laws and regulations that govern biosafety we use in our project.

General biosafety standard for microbiological and biomedical laboratories(WS 233-2002).

Biosafety Law of the People's Republic of China

Laboratory management manual

Safe Human Practice

In Human Practice, we hope to hear the real voice of the society. But on the premise of ensuring the feedback is effective, we should also respect the feelings and privacy of interviewees.

First, we need to ensure the safety of the interviewees. We believe that face-to-face communication can have a greater chance to get people's real thoughts, so the street interview is a very important part of our project Human Practice. But we also have an obligation to avoid any danger that might occur during the interview in the real world.
In the street interview, we hoped to know the mosquito repellents methods and trends adopted by children or the pregnant. We wanted to find and interview parents among the crowd. So, we found child first, and then we could find the guardians to be our interviewees. Although this method was efficient, it could also have some hidden dangers. Children must be carefully watched by guardians to ensure their safety. However, interview has a high probability to divert parents' attention from their children. We do not want any accident to happen during the interviews, so we have developed a set of procedure for selecting interviewees (Fig.1). In order to ensure safety, parents would only be selected as our interviewees when their children were in a safe state such as resting or there were others to take care of children, and we ensured that the interview would not last for a long time.
In addition, we are also focused on quarantine requirements during novel Coronavirus pandemic. In each interview, we wore masks and kept a safe distance from the interviewees. We also washed our hands after going out, ensuring that we are not threatened by the virus.
We also won't forget to use mosquito repellents to prevent mosquito bites when we go out for Human Practice.

Fig1. procedure for selecting interviewees

Second, we need to respect people's privacy and information security. It is well-known that the interview content should be approved by the interviewee before being shown to the public. After each interview, we asked interviewees if they would allow us to post photos and conversations on the wiki. Most of the applications were granted, but some of the information was not suitable for public disclosure.
In our Human Practice interview, we may talk about some sensitive information when we interview government and so on. But we as college students may not be able to consider what information is inconvenient for public disclosure. Therefore, we will still contact the interviewee after the interview and send the interview documents to the interviewees for inspection. If some content doesn't fit, we'll write it briefly or delete it. Therefore, some of content in the Human Practice page may be ambiguous. Although it is not convenient to show, the interview content and suggestions had been absorbed by our project.