Of CO₂urse

2018 NCKU Tainan team strives to reduce the concentration of carbon dioxide (CO₂) with the approach of synthetic biology. We constructed a carbon fixing E. coli by cloning enzymes from Calvin cycle into it. We measured the function of each enzyme in the pathway and proved that the engineered pathway can utilize carbon. Our team has also designed a bioreactor. The bioreactor contains an air valve in which we can pump the CO₂. The bioreactor is also monitored by sensors that will send the data to a cloud database. Combining IoT and synthetic biology, we believe that our device can be applied to industrial settings. To promote our design as well as synthetic biology, we have discussed with numerous experts in various professions and visit the entrepreneurship that is willing to apply our design. We received countless feedbacks and improve our project. We believe that people should be aware of CO₂. We also believe that our project can help the society to get one step closer towards a low carbon society.

It is not exaggerated to say that us, human being, are at the crisis that stems from CO₂ since the industrial revolution in the 18^th century.

Greenhouse effect brings a lot of side effects to us. For example, glacier retreats, which contributes to the rise of sea level and the decrease of habitable land. Besides, the rise of temperature accelerates the chemical reaction in the sea, depleting the coral reef and lead to the unbalanced marine ecosystem. The frequency of natural disaster has drastically increased over the past few decades. If the global temperature rises 1 degree Celcius, one-third of the land will be lack of freshwater. 2 degrees Celcius, over millions of species will go extinct. 4 degrees Celcius, the glacier in the Northpole will melt completely.

If we do not pay attention to this ongoing crisis, we will face the risk of extinction as the situation is getting worse. As one of the members of the global village, our team, NCKU_Tainan thinks that we should enroll ourselves in reducing the emission of greenhouse gases (GHGs). This year, our team have designed a new way to utilize one of the GHGs, CO₂, by using an advanced and modern technique nowadays, Synthetic Biology. Without replacing other ways, our team offers an alternative to utilize carbon dioxide.

With the aim of reducing GHGs emissions, the industry has developed various energy saving and carbon reducing manufacturing process. CO₂ emissions in the factory are currently processed by the technology of Carbon Capture Storage and Utilization (CCS & U). Development of CCS & U is a crucial factor in reducing directly CO₂ emission.

After doing some research, we cloned gene fragments that can express PRK, CA and Rubisco into E. coli. All of the genes are originated from a unicellular cyanobacteria strain, Synechococcus elongatus PCC 7942 and Synechococcus elongatus PCC 7002. After cloning three gene fragments into E. coli, a new metabolic pathway that can utilize carbon dioxide was established, subverting the cognition that only autotrophs could utilize CO₂.

Initially, E. coli will uptake xylose from the cultivation medium. After that, xylose will be metabolized into Ru5P by its own native metabolic pathway. Next, PRK catalyzed the phosphorylation of Ru5P to RuBP. RuBP will be carboxylated into two molecules of 3-PGA. 3-PGA will be converted into a multifunctional intermediate, pyruvate.

In order to expand the scope of our project to be used in the field, our team have designed a device to let our engineered E. coli to utilize CO₂ in real life. The device can be divided into three main parts. Our bioreactor consists of a pH meter, a thermometer and a CO₂ sensor, a nutrient tank, containing a fed-batch culture system and a collection tank to collect waste and product at the downstream of our device.

Next, for the consideration to the real time internal condition monitor of our device, we have designed an App. No matter where you are, users could determine the progress of bioreactor with the immediate data of temperature, CO₂ concentration and pH value. These data come from the sensors on our device which will be showed on the App through the database, uploaded by WI-FI module.

In the Integrated Human Practice, we improved our project from different activities in different aspects. We visited experts in many kinds of specialties when we encountered difficulties. Their instant feedback helped us walk in the right direction. Besides, our project converges diversify fields, so the more suggestions we had, the more integrity we propose.

As for the application of our project, industrial interviews supports us to improve our project. Each time we held an interview with an enterprise, we get more suggestions and were able to meet their needs. One of the important concern of the enterprise is to maximize the benefit and reduce the cost simultaneously. Besides, meeting up with other iGEMers built a strong friendship with those who also have a strong interest in synthetic biology. We also seek the opportunity to collaborate and create a win-win situation.

For the education and public engagement, we attempted to introduce synthetic biology to the students and public in a more interesting way. The more people we affect, the more people we can cooperate.

Different from normal courses, we designed easy going and interesting experiments and app games for students and the public, which led them to become interested in iGEM. After these activities, their feedbacks helped us to understand their thoughts and we were able to adjust and improve our presentation for the next time.

Furthermore, we participated in a festival held within our university NCKU as well at a medical conference within the medical school and operated our fan page to increase the exposure of our project, as well as synthetic biology and iGEM. Our fan page also aided in raising the awareness of iGEM in our school, which attracted more student to join us.

Reference

1. “TIL: It's Currently 20°C Hotter In The North Pole Than It Should Be.” Busy, 21 Nov. 2016, busy.org/@sirwinchester/til-it-s-currently-20-c-hotter-in-the-north-pole-than-it-should-be.