1 Design Safety
1.1 Chassis Safety
Saccharomyces cerevisiae is a widely used model eukaryotic microorganism classified under Biosafety Level 1 (BSL-1). It is non-pathogenic to healthy humans and the environment [1]. With a clear genetic background and well-defined metabolic pathways, it is a commonly used chassis cell in synthetic biology and industrial biotechnology. Under standard laboratory conditions (BSL-1), S. cerevisiae requires no special protective measures and can be inactivated by routine disinfectants (such as ethanol or bleach). To prevent potential harm from engineered yeast and plasmids in open environments, we have designed an auxotrophic system to ensure that the bacteria cannot survive in the wild under uncontrolled conditions.
1.2 Safety Module
By knocking out key metabolic genes in yeast—URA3 (involved in uracil synthesis) and LEU2 (involved in leucine synthesis)—we have engineered strains that depend on external supplementation of uracil and leucine for survival. In the event of accidental release into the natural environment, the engineered strains would be unable to proliferate due to lack of essential nutrients, leading to natural cell death and preventing potential transmission.
2 Laboratory Safety
2.1 Safety Regulations
When conducting synthetic biology research, we prioritize experimental safety. The project team always places the health of personnel and environmental protection first. We have established a comprehensive safety management system to ensure that all experimental processes are safe and controllable. Strict laboratory safety protocols and standard operating procedures have been developed. Regular safety inspections are conducted to continuously optimize safety management processes. Furthermore, complete protective equipment and emergency response facilities are available. Through these measures, we strive to create a safe and standardized research environment, minimizing experimental risks, protecting researchers' health, and avoiding potential environmental impacts. The team will continue to improve the safety management system to ensure the safe and orderly conduct of scientific research.
Figure 1,2(left and middle) Laboratory firefighting facilities
Figure 3(right) Laboratory emergency shower head
Figure 4(left) Laboratory High-Temperature Steam Sterilizer
Figure 5,6(middle and right) Instructions for use of laboratory washers and equipment
Figure7,8,9 Instructions for use of laboratory washers and equipment
2.2 Safety Training
All team members are required to undergo unified safety training. Instructors place special emphasis on the use of equipment such as high-pressure steam sterilizers. Members must pass a unified safety knowledge assessment before being permitted to conduct experiments in the laboratory.
Figure 10 Laboratory safety knowledge assessment questions
3 Product Safety
3.1 Raw Material and Formula Compliance
When used as cosmetic ingredients, the engineered S. cerevisiae strains and their metabolites involved in this project will strictly comply with national regulations such as the Cosmetics Supervision and Administration Regulations and the Safety and Technical Standards for Cosmetics, along with other relevant laws and requirements [2]. All components will undergo safety assessments to ensure their safety, stability, and efficacy in cosmetic applications. Fermentation products and extracts from the engineered strains will meet cosmetic ingredient standards, containing no prohibited substances and adhering to limits for restricted substances.
3.2 Production and Quality Control
If the project proceeds to the production stage, we will strictly implement the Cosmetics Good Manufacturing Practice (GMP) [3] to ensure that fermentation, extraction, and processing are conducted in a compliant clean environment. A full-process quality control system will be established, involving strict testing of raw materials, intermediates, and final products for key safety indicators including microbial limits, heavy metals, and pathogenic bacteria, ensuring that product safety meets national standards.
In summary, this project has established a multi-layered, full-lifecycle safety assurance system through the selection of safe chassis organisms, the design of safety modules, adherence to strict laboratory operating procedures, and planning of regulatory-compliant product development pathways. We are deeply aware that safety is the cornerstone of scientific research. In the future, we will continue to uphold a highly responsible attitude toward personnel and the environment, constantly reviewing and optimizing our safety practices.
