Severity of antibiotic pollution
Antibiotics are widely applied to the prevention and treatment of diseases, saving countless lives. But at the same time, antibiotics also cause problems. In 2013, China consumed 92,700 tons of antibiotics, and ~58% of them are discharged into the environment, causing serious pollution and antibiotic resistance. About 700,000 people die of antibiotic resistance each year worldwide.
Existing antibiotic treatment methods
Although several physical and chemical methods have been used to degrade antibiotics in the environment, such as ozonation, Fenton oxidation and adsorption, one cannot ignore their disadvantages, including high cost, complexity, and producing new pollution.
Comparing with them, biological methods are more effective and environmentally friendly.
Expired drugs — Close to our life
Antibiotic pollution not only comes from its production, such as pharmaceutical wastewater, but also origins from its usage, such as medical antibiotics, which are not far from our daily life.
Every family have to face the problem of expired antibiotic drugs, but few people realize that expired drugs are being improperly treated such as incineration and landfill.
A CIP-sensitive dergradion system
Among antibiotics, ciprofloxacin (CIP) is widely used and easy to cause resistance. However, people did not notice the importance of this.
In our project, we have constructed an engineered bacteria to effectively degrade CIP by introducing a CIP-sensitive promoter, PtisAB and a CIP-degrading protein, CrpP. By this way, CrpP will be produced once the system senses the presence of CIP, and CIP is consequently degraded.

Hardware and modeling

for supporting the system

To use engineered bacteria more effectively, we built an expired drugs recycling and degrading device. We optimized this device and successfully achieved the detection of CIP by collecting GFP fluorescence emitting from engineered E.coli, which has a linear relationship with CIP present in the environment. Modeling analysis provided the guidance for the layout of this device in the social community.
Conclusion and Outlook
In our project, we have successfully constructed the CIP-sensing and CIP-degrading system. We also developed its supporting hardware. Although more work needs to be done in the near future to optimize the system, there is no doubt that our project will provide new insight and useful guidance for biodegradation of antibiotics.
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