During our iGEM journey, we have not only progressed and grown in completing our own projects, but are eager to share our experiences and achievements with the iGEM community and a wider audience. In this section, we will introduce our contributions to the iGEM community and the next-generation iGEM team, which can be roughly divided into three areas: synthetic biology tools, laboratory skills, and education.
Synthetic Biology Tools
Warmth Suicidal Circuit
One of our outstanding contributions to synthetic biology tools is the construction of a temperature-sensing suicide pathway. The temperature-responsive synthetic pathway is a commonly used logic gate design in synthetic biology. In our project, it is used to control the fate of engineered bacteria that escape from the body. Traditional suicide pathways used for biosafety often only have a single logical response function, which not only risks triggering early during the production process, but also fails to achieve the purpose of artificially controlling the opening time. To this end, we designed and successfully constructed a system based on a biphasic steady-state switch, and characterized its characteristics through wet laboratory experiments and mathematical modeling.
It is worth noting that the input signal of the suicide pathway we designed is a promoter that senses temperature changes and external inducer concentration, so different input signals can be obtained by simply replacing different promoters. This enhances its versatility and potential applications. Therefore, the biphasic stable switch suicide system developed by ZJU China 2024 has broad application prospects in the field of synthetic biology.
Quorum Sensing Element
In addition, our contribution to synthetic biology is to reconstruct the quorum sensing pathway. The quorum sensing (QS) pathway is a common tool in synthetic biology and is often used to control the density of engineered cells and regulate related metabolism. However, due to the high leakage rate of the QS system, its application has certain limitations. Therefore, we designed and constructed QS systems with low leakage rates and different cell density thresholds.
Interestingly, we improved the QS system mainly by optimizing the sequence of Luxbox and the number of CRP binding sites. Different numbers of CRP sites and Lux-Box sequences will bring different leakage rates and cell density thresholds. This will allow everyone to use different variations to set the effect they want.
Hydrogels characterization improvements
In our project, we constructed a hydrogel that can be secreted by microbes.This hydrogel protein was designed as a triplet —— coiled protein CsgA, tag 6 His for ligation and examination, and the cytokine TFF, expected to tether TFF to a coiled fiber matrix to construct self-coiled hydrogels.
CsgA acts as a coiled protein, here as a scaffold for the hydrogel. And, TFF, as a small protein secreted by mucus-producing cells from the gastrointestinal tract and other mucosal surfaces, can be used to promote epithelial recovery and can also inhibit intestinal inflammation. This self-assembled hydrogel can repair the intestinal mucosal barrier while enhancing the adhesion and colonization of engineered bacteria against colonization by pathogenic bacteria.
A simulated gut test system:
In order to test the actual effect of the developed engineered bacteria, it is necessary to design biological experiments to evaluate their antibacterial effects. Since biological experiments do not belong to the category of this competition, and considering the more time and money required by biological experiments, we designed a test system for in vitro testing of engineered bacteria.
We used the stem cell induction method to construct a simulated human intestinal environment in which the simulated intestinal environment conducts biological experiments. In order to reduce the subsequent artificial experiments to evaluate the antibacterial effect, we designed an electronic measurement system to roughly measure the distribution of colonies in each part of the dish through the size of the colonies and the image of the fluorescently labeled antibacterial peptides, so as to roughly evaluate the antibacterial effect of the drug.
Laboratory Skills
ZJU Molecular Biology Laboratory Skills Manual
Molecular biology experiments, such as plasmid construction and PCR, are an important part of synthetic biology projects. However, for beginners, following instructions in a biological kit can lead to errors and make it more difficult to understand the rationale and significance of each step. Therefore, based on our experimental experience in the iGEM laboratory, we compiled the "ZJU Molecular Biology Laboratory Skills Manual", which covers common molecular experimental techniques. Compared with other laboratory manuals, we provide more detailed and specific content in terms of detailed operations, and explain where necessary to ensure that even beginners can understand the principles of each step. We will work with the Zhejiang University Next Generation iGEM team to continue to revise and improve this manual.
We have open sourced the English version of the "ZJU Molecular Biology Laboratory Skills Manual". We welcome your valuable suggestions and feedback on the "ZJU Molecular Biology Laboratory Skills Manual".
Laboratory Safety：All Takes Two
Laboratory safety is also an important part of iGEM. Especially when conducting experiments, everyone must prioritize laboratory safety. We have established and refined laboratory safety protocols known as the “All Takes Two” system. This means that we will be working in pairs as we perform each experimental procedure. This system effectively avoids risks associated with personal negligence.
To learn more about the All Takes Two system, visit Safety.
Education
Pay Attention to Human Groups——Human Practice
The work of our team human practice revolves around the concept of "people-oriented". We have conducted extensive contacts with stakeholders and received a lot of feedback. One of our contributions to synthetic biology is to alleviate social inequalities and enrich the public's scientific knowledge through educational efforts.
Super eco’s low cost and convenient use help it be widely accepted by people, which greatly helps our human practice work. On this basis, our human practice work covers rural and urban areas, focuses on the issue of inequalities in medical resources, builds bridges between projects and practice, and continuously improves our projects. At the same time, we also widely promote synthetic biology through educational work. knowledge about food poisoning and food poisoning, and called on the public to pay attention to food health; finally, we also accumulated original funds through entrepreneurship and put products into grassroots areas to alleviate inequality.
MRSAkiller——Intestinal Health Science Guide
In order to increase public understanding of synthetic biology and gut health, we designed and drew illustrations for the "MRSAkiller—Gut Health Science Guide." This handbook conveys knowledge about synthetic biology and gut microbiota and health in simple, easy-to-understand language with illustrations. ZJUChina2024 works closely with high schools in Xihu District. We distributed these educational manuals to high school students and look forward to their positive feedback.
We have open sourced the Chinese version of "MRSAkiller—Gut Health Science Manual" for educational purposes. We also welcome your valuable comments and suggestions on our documents.