Team:CSU CHINA/Implementation


Proposed Implementation


Even an excellent iGEM project is only helpful when it can be applied under real-world circumstances.

To enhance our algae’s feasibility and make good for the real world, we carefully listened to stakeholders. With factual feedbacks, we figured out their expectations and integrated the opinions in further design.

Application in Sewage Treatment Plant

To understand the existing wastewater treatment technology, evaluate the application and listen to others’ suggestions, we visited two Sewage Treatment Plants and asked some experts for advice.

We described our program carefully, and after listening to our introduction, experts all agreed that our project has a good application prospect, but also informed us:

  • The most critical factor influence application is the cost. Biosafety and Cadmium removal efficiency also counts!
  • Think about continuously improving the process’s processing capacity by debugging and practicing operations at a low cost. If the engineered algae’s survival and proliferation and cadmium removal activity do not require high environmental factors, the price will be low.
  • Consider operator training, infrastructure construction, other up-front investment, routine equipment maintenance, and waste recycling.
  • Making a fair presentation of these careful considerations will make the project more compelling to relevant enterprises.

Visit KAIFU Sewage Treatment Plant


Safety is an indispensable priority when we design the device from synthesized cells. Lack of full application to test the system to enhance the security, we strictly studied and analyzed all possible biosafety issues caused by our system.

Design safety

Our project does not include gene drives, nor have we worked with animals. All species names (including strains) have been listed in the safety form.

The Synechocystis sp. strains PCC 6803 we use in this project are 1st-Risk-Group organisms with little safety risk to the environment or pets.

Our project is generally performed with very low risks, as no pathogenic bacteria or hazardous chemical reagent is used. However, some familiar chances are still inevitable. For example, get contaminated while using nucleic dye and get burned while using a spirit lamp, especially in the super clean bench. Some reagents are toxic, like DMSO, ethidium.

Implementation Safety

We tested the farmland system and continuously monitored the pollution index to test system performance and potential safety risks. To prevent accidental leakage of algae and reproduction in the natural environment, we build the Safety Model in the Model page to ensure its workability.

For the device, due to COVID-19, we didn’t make it implemented to ensure its safety, so we envisioned its workflows and built an Absorption Model to virtually test its

Laboratory Safety

In Central South University, our school issues the laws of laboratory safety rules governing the biosafety, which follows the rules of Biological safety management regulations for pathogenic microorganisms Laboratory issued by China State Council.

Our lab follows the China National Institute of Pathogenic Microorganisms Biosafety Management and Central South University Laboratory Safety Rules.

Application in Farmland

We realized that cadmium-polluted rice is widespread, severe and harmful to human health through the interviews with our end users. Today, farmers do not have the equipment or methods to detect and treat cadmium contaminated irrigation water. If they grow substandard rice, the only way they can do is to throw it away, causing substantial economic losses.

After introducing the device’s design, farmers were worried about the chemical reagents we used in the toxin-antitoxin suicide system. Will these chemicals directly put into the farm produce secondary pollution that will affect rice growth and poison the rice?

Then, we changed the toxin-antitoxin system to the second generation of the red and blue light control system. We could achieve the cadmium removal function of algae by adjusting the light, so there is no secondary pollution of the chemical reagent.

After that, we revisited farmers with our new design. This time they accepted improved devices that use LED tubes. The portable and rechargeable battery can be charged directly and conveniently, which fostered its application. Also, we calculated the rupture time of the glueball through modeling. We instructed the farmers to collect cycas within this time, making it more convenient and safer. However, farmers reckoned that the second-generation system was too complicated to operate for them. Also, there would be more electricity bills.

How to reduce costs further? After research, the third generation of blue light regulation of the suicide system has been realized. Based on the red and blue light system’s tedious regulation and the low-cost performance of algae reuse, we simplified the system’s operation, saving energy and reducing costs.

Team members visited farmland

Team members learn about the irrigation water

To make an auto-machine in farmland. We designed a fly-catcher-like device. A blue light source is placed at the center’s bottom to deactivate the safety system in cells. Algae in microbeads release oxygen continuously. Gas fuses into a bubble or two inside that provide buoyancy. The microbeads could float as the bubbles grow.

Meanwhile, the absorption process is still in progress. One of our model’s main goals is to optimize parameters to match the saturation time and float up to maximize its efficiency. Once the absorption process is done, we expect the microbeads to flow on the surface. Once a microbead floats on the surface, it can just float for a while and rupture, then fall into a groove on the top of the device, waiting for salvage. Hence, the process of absorption and salvage is separated on time and space scales. And you can get more information about

Implemented device that we envisoned


How to ensure the sustainability of the device?

By communicating with engineers, we have also improved our experimental thinking regarding cost, therapeutic efficiency and biosafety. For example, to reduce the project cost, we designed a kind of environmental protection and energy-saving lighting equipment instead of chemical products to control engineered algae’s biological activity.

How to simplify the operation of the system?

We conducted several interviews with local farmers. Based on feedback, we redesigned the device with a portable rechargeable battery that could charge directly and conveniently, which confirmed the practical application. After consulting students in CSU majored in automation, we put forward the automation design scheme in the following paragraph.

Future improvement

If possible, the future CSU China team could continue to develop the project in 2021. We plan to install microelectronics, including LTE and GPS modules and photoresistors, in the device to sense the current light intensity and access future light intensity information from the local meteorological department by LTE. With the data sent to an app installed on the user’s phone, an algorithm based on our model inside the app will provide the user with the best salvage time.