Team:OUC-China/Description
Background
Antibiotics have been our superweapon against pathogenic bacteria and play a vital role in human health and agricultural production. However, the environmental occurrence and ecological risks caused by the widespread use of antibiotics have also attracted wide attention．A research on the surface water of East and Southeast Asian countries have found that antibiotics are ubiquitous in surface water of these countries with concentrations ranging from <1 ng/L to hundreds μg/L[1].
The occurrence of antibiotics and their degradation products in the aquatic ecosystems can pose a threat to non-target organisms of different trophic levels including bacteria, algae, plants, invertebrates, and fish. Meanwhile, antibiotic residues in the environment are related to the development of antibiotic resistance genes (ARG) and antibiotic-resistant bacteria (ARB), which have been considered as the most critical risks that made us have no medicine to use[2].
As far as we know, the current high cost of antibiotic testing like LC(Liquid Chromatography) also limits the long-term large-scale testing of antibiotics. To address this problem, we launched our program AllPASs.
Solution
Synthetic biology is creating new capabilities for engineered biological systems to address pressing global challenges through repurposing, evolving and rewiring the functions of biological components for a range of applications [3].
Among these functions, the ability of cells to use molecular biosensors and genetic networks to sense and respond to changing conditions is being harnessed to create new pollutant detection technologies[4].
So we decided to use synthetic biology to design a whole-cell biosensor to detect antibiotics in the environment. Our concept is greatly inspired by cell-free biosensors[5], but due to the other advantages the WCB(whole-cell biosensor) has like it is Cheap, better identification of some pollutants, good stability, and easy to achieve high-throughput automation. We ended up doing a WCB.
Our Research
Our project designed a series of whole-cell biosensors (WCBs) to detect three kinds of common antibiotics: tetracycline, chlortetracycline, erythromycin. To break through the common limitations of WCBs, a fluorescent RNA aptamer is used as the output signal to increase the response speed, and it is hoped that the signal-noise ratio and dynamic range of the sensor can be improved by the NIMPLY logic gate gene circuit composed of CRISPRi and strand replacement reactions.
From a user perspective, a simple device is designed to carry our WCBs. Its output signal can be read and analyzed by smartphones，making field tests possible.
Beyond Research
As we know, the pollution sources of antibiotics mainly come from hospitals, pharmaceutical companies, aquaculture, and livestock farms[1].Outside the laboratory, we conducted a series of human practices, including investigating pharmaceutical factories, sewage treatment plants and aquaculture farms. They all showed their interest in our products and said they would consider buying them if the cost was appropriate, which made our research more meaningful. We have also carried out a series of education programs to educate primary, middle and high school students about synthetic biology and the dangers of antibiotics. Finally, considering that there is no clear standard for antibiotics in water environment in China at present, we drafted one together with students from the Law School of Ocean University of China.
We really hope that our efforts can make a small contribution to environmental protection and human health.
For more details of our Beyond Research click on Sustainable
References
[1]Anh H Q, Le T P Q, Da Le N, et al. Antibiotics in surface water of East and Southeast Asian countries: A focused review on contamination status, pollution sources, potential risks, and future perspectives[J]. Science of The Total Environment, 2021, 764: 14286
[2]Felis, E., Kalka, J., Sochacki, A., Kowalska, K., Bajkacz, S., Harnisz, M., Korzeniewska, E., 2020. Antimicrobial pharmaceuticals in the aquatic environment–occurrence and environmental implications. Eur. J. Pharmacol. 866, 172813.
[3]French K E. Harnessing synthetic biology for sustainable development[J]. Nature Sustainability, 2019, 2(4): 250-252.
[4]Slomovic, S., Pardee, K. & Collins, J. J. Synthetic biology devices for in vitro and in vivo diagnostics. Proc. Natl Acad. Sci. USA 112, 14429–14435 (2015).
[5]Jung J K, Alam K K, Verosloff M S, et al. Cell-free biosensors for rapid detection of water contaminants[J]. Nature biotechnology, 2020, 38(12): 1451-1459.