Team:AHUT China/HP FOR SILVER

Royal Hotel Royal Hotel







   1.Cooperation with the Indian Institute of Technology

As the project continues to advance, HP's exchanges and cooperations between teams are more frequent and in-depth. After seeing the cooperation application issued by the iGEM team of the Indian Institute of Technology (IIT-Madras) at the iGEM official website, we contacted IIT-Madras to discuss cooperation actively.

We are pleased to collaborate with the iGEM team of the Indian Institute of Technology, Madras (IIT-Madras) to make a video on the science of synthetic biology in the mother tongue. The Indian Institute of Technology is also working with other teams in English, Tamil, Telugu, Kannada, Malayalam, Marathi, Bengali, Gujarati and Hindi.

IIT-Madras sends an English script to our team. We need to match the provided slideshow video with the provided text and add the translated text to the subtitles, and finally make it into Chinese video.

We thought it was a simple matter, but there were some problems at the beginning. The problems are summarized as follows:
1. The English script does not exactly match the sound in the video, and some paragraphs are missing.
2. English and Chinese belong to different language families. They are slightly different in grammar, and the word order is reversed in translation.
3. Some video pictures and sounds are out of sync and need to be adjusted.
4. Our team members are not familiar enough with the Indian accent in English, and some words cannot be completely accurate.

After consultation and repeated revisions by the iGEM team members of the Anhui University of Technology, four days later, the results were satisfactory and the video was sent to the iGEM team of the Indian Institute of Technology. We have established a good relationship with the iGEM team (IIT-Madras) of the Indian Institute of Technology, Madras.

With the successful completion of the HP cooperation, the Anhui University of Technology iGEM team (AHUT-CHINA) looks forward to more cooperation opportunities with the Indian Institute of Technology iGEM team (IIT-Madras).









2.Visit Hua Qi environmental protection company

On the afternoon of September 12, 2018, our team AHUT_China visited Ma'anshan Hua Qi Environmental Protection Technology Co., Ltd. (Hereinafter referred to as HuaQi Environmental Protection Company).


We know that environmental pollution is mainly air pollution, water pollution and soil pollution. Our project is to deal with greenhouse gas CO2 in air pollution. How to deal with greenhouse gas CO2 efficiently is particularly critical as the increasing greenhouse effect has a serious impact on the global environment. In order to gain a deeper understanding of the current environmental pollution in China, we visited HuaQi Environmental Protection Company HuaQi Environmental Protection Company, is a company specializing in sewage treatment. After Ms. Zhang Qi introduced the company, we visited the intelligent water transportation management system and laboratory.




Fig.1 Technical staff Liu Shanshan led us to visit the laboratory




Liu Shanshan, the company's technical staff, led us to visit the laboratory. During the visit, we learned that water pollution is currently harmful to the environment and people's health. So, water pollution treatment is very important. We introduced our project to computerize the protein molecules expressed by carbonic anhydrase gene mutations to obtain carbonic anhydrase (CA-2) with high thermal stability and import it into E. coli cells in order to achieve efficient collection of CO2. The project is currently in the theoretical stage. She is interested in our project. If the CO2 emission can be effectively controlled at the source, the problems such as the continued destruction of ozone layer, the melting of two-stage glaciers and the rapid extinction of a large number of species can be effectively solved. And she is more concerned about how this project can be applied in practice, and puts forward some suggestions for our project. At present, the CO2 gas capture technology mainly includes chemical absorption, pressure swing adsorption and membrane separation. She suggested that firstly transgenic E. coli be cultured in solution environment with chemical absorption to achieve CO2 collection, and that secondly CO2 be treated with biological rotating disc.




Fig.2 Group photo at HuaQi Environmental Protection Company (second from right: Liu Shanshan)





3 . iGEM(Linkoping_Sweden)

We saw the cooperation request issued by Linking University's iGEM team (Linkoping_Sweden). Linkoping_Sweden has a new idea of cooperation. They want all the teams to use letters or emails to show interesting things happening inside and outside the team. So we participated in this cooperation. This is an interesting collaboration, as it may be boring during the experiment, but the stories that happen in the experiment make the experiment fun. And by organizing these stories, we learn more about our experiments.




Fig.3 Mail sent to Linköping University


Fig.4 Reply email from Linköping University





4. Our Meeting

Background: Each team's project in IGEM is not perfect at the start.In order to make project perfect and make the team members cooperate with each other more and more smoothly,each team holds the team meeting to discuss again and again. So it is important for us to hold meetings to make some discussions.The members of the IGEM in our college held a conference every week to discuss how to solve our current problems and how to do next.

The text: Our members of iGEM keep the habit of discussing at meetings once a week since March 10.

On March 10, the conference included that:

    ①Division of labor at that time.
    ②Members of the experimental group introduced the carbon dioxide capture project
    ③We made a plan for the next step.
    Through the discussion at this meeting, our division of labor has become more rational and the efficiency of work among members has been fully improved,and at the same time, our team members got a preliminary understanding of the project that we are going to carry out.




  

Fig.5 Our Meeting




On March 17, the conference included that:

    ①The most common type of CO2 fixation technology in the current stage.
    ②The expression and the Catalytic reaction mechanism of carbonic anhydrase in human, animal and plant;
    ③The living environment of carbonic anhydrase and how to maintain catalytic activity of carbon anhydrase.
Through the discussion at this meeting, we learned that traditional CO2 fixation technologies include chemical/physical solvent absorption, membrane absorption, deep-sea fixation, etc.

However, these methods have been proved to be extremely expensive in practice, and they further prove that the use of carbonic anhydrase as a potential biocatalyst is a promising fixation method.


On March 24, the conference included that :

    ①The basic knowledge of biological brick.
    ②The main function of carbonic anhydrase in our project;
    ③We arranged the mission about HP and Collaboration.
Through this meeting, we knew that it was helpful for the experimental group to design and transform the biobricks in the later stage. And some other works were arranged, so that we can be prepared for the following assignments.


On March 31, the conference included that ：

    ①The experimental group summarized the basic professional knowledge related to the competition
    ②We initially summarized the schemes of HP and collaboration.
    ③Our instructors tell the students who go to the United States how to get the visa .
Through this meeting, we made our parts of HP and Collaboration more complete and detailed.


On April 14, the conference included that ：

    ①The experimental group needs to understand the basic knowledge of genetic engineering.
    ②The activities of hp-related are determined by the group of HP and collaboration.
    ③Interpretation of the standards of the Medal.
Through the discussion in this meeting, we have listed the ways of expert discussion and external communication for the activities of HP and collaboration. Meanwhile, the members of the experimental group are planned to start the research of Interlab, and some members decided to participate in CCIC held in Shanghai during the summer vacation.

On April 21, the conference included that :
    ①We should complete the preliminary research of Interlab:We need to test the device which is in the DNA KIT needs to be sent to the United States, and GFP fluorescent protein expression may be required.
    ②The members of the group of HP and Collaboration gives us some feedback on opinions of relevant government officials of the municipal environmental protection bureau.
    ③Our instructors tell the students who decide to go to the United States to fill out forms of DS160. Through the discussion in this meeting, we planed to complete the test report of Biobrick and submit the Excel data form before the registration time of Interlab on July 9 (as of September 29). Meanwhile,the members of the group of webpage should begin to design wiki pages and other related contents.




Fig.6 Our Meeting




On April 29, the conference included that :

    ①The experimental group should complete the ot-2 application before May 1.
    ②The group of the HP and Collaboration should continue to work on related activities.
Through the discussion in this meeting, we asked the experimental group to conduct a detailed research on Interlab in the next stage. Meanwhile, the members of the group of HP and collabarbitration need to investigate the previous Collaboration projects and make a summary.


On May 13th,the conference included that :

The Interlab research of the experimental group was completed, and the instructor should plan for the following projects.The members of the group of HP and Collaboration had completed the research of the collaboration.Through the discussion in this meeting, we planed to continue to improve the website design of the wiki in the next stage,and the website design needs to conform to the theme of this year. Meanwhile, the experimental group should pay attention to collecting some relevant experimental pictures used on the wiki when conducting experiments.


On May 19th，the conference included that :

The tasks of each group are still in the completion stage, and we should discuss the existing problems in the next conference.Through the discussion in this meeting, we planed to complete the exhibition of posters of CCIC in Shanghai in the next stage and complete the presentation of related projects.


On June 8, the conference included that :

    ①The experimental group needed complete the four forms online,the Data Form and Project Description, and the Safety Form (referring to the completion of 17 years) before June 29;
    ②The group of HP needed to hold a lecture in our college.
Through this meeting, our team members had a high degree of tacit understanding, and the atmosphere of the discussion became more and more lively.


On July 27, the conference included that :

    ①The experimental group completed the uploading of Interlab experiments and records.
    ②The Logo production is completed by the group of art layout.
    ③One of the HP activity is completed by the members of the group of the HP and Collaboration.
Through this meeting, we planed to meet the requirements of IGEM gold award for the next phase of the experimental .Two different wiki designs should be prepared for the web page team,and the modeling group needs to dock with the experimental group to find a solution to implement mathematical modeling.




Fig.7 Our Meeting




On August 23, the conference included that :

    ①The experimental group completed a certain of Biobrick designs, and the experimental group estimated that two improved biological bricks and two new biological bricks will be submitted.
    ②We voted on the wiki design.
Through the discussion in this meeting, we asked the modeling group to model the reaction of carbon dioxide airflow with saturated carbonic anhydrase solution after the investigation is made clear. The work of each group will set the Deadline mechanism and strictly stipulate the completion time.


Conclusion: Our IGEM team of Anhui University of Technology discussed and solved various problems in the progress of our project through conferences.And our final project has been improved;the members have more and more trust in each other.The conference is still going on, and our story is still going on.I believe that IGEM team will be able to achieve success in this year's competition!





    5. Meeting of four schools

September 9, 2018, We arranged a video conference with members from northeastern university, Shandong University and northwestern University. During this time, we briefly introduced our project background and project ideas and planned the agenda of the meeting. As the greenhouse effect has become a common concern in recent years, how to effectively capture carbon dioxide has become a worldwide problem. At present, carbon dioxide capture mainly includes absorption, adsorption and membrane method,which are renewable energy consumption of high cost and have twice as many pollution problems. The use of CO2 to capture the high catalytic efficiency and environmental friendliness of the carbon anhydride has aroused wide concern.






Fig.8 Meeting with three other universities




So our Anhui University of Technology team put forward a project on the generation of carbon anhydride through E. coli to absorb carbon dioxide. First of all, our project successfully expressed the Wide-type carbonic anhydride enzyme in Escherichia coli, however, due to its poor stability and ease of deactivation, its industrial applications were limited. Therefore, based on the molecular simulation technique, the effect of mutation of amino acid residues on the conformation and activity of enzymes was studied, and the mutant carbonic anhydride with high thermal stability was obtained. The experimental results show that the purified mutant carbonic anhydride has higher stability and activity than the wild type of carbonic anhydride enzyme, which realizes the effective capture of CO2. Northeastern university, Shandong university, and the members of Northwestern University have expressed their strong interest in the project of Anhui University of technology, so we have the highlights of our project and other members of the school exchange. Highlights: 1, Instead of the high cost, high efficiency and poor circulation of traditional methods, we choose a safe and environmentally friendly method with low cost and high catalytic efficiency for trapping CO2 with carbon anhydride. 2,By using the molecular simulation technique, the amino acid as the basic unit, the effect of remnant radical mutation on the two-stage structure of the carbonic anhydride enzyme, and the influence of the molecular conformation, the best amino acid mutation site was obtained, and the thermal stability of the enzyme was improved without affecting the enzyme activity. 3, We obtained the expression of wild type and mutant carbonic anhydride enzyme strains of Escherichia coli, and two kinds of carbon anhydride enzyme in vitro purification, wild-type carbonic anhydride enzyme has a certain CO2 capture efficiency, more importantly, the mutant than the wild type of carbonic anhydride enzyme has better stability and activity, realize the CO2 efficient capture.




Fig.9 Meeting with three other universities




Students from Tohoku University also briefed members of our other schools about their projects, and the Tohoku University project was inspired by the prevalence of fast food and the acceleration of urbanization, with the number of inflammatory bowel diseases (inflammatory bowel disease, IBD) rising in Asia, And the risk of developing colorectal cancer (colorectal cancer, CRC) in patients with IBD also increased. There are no drugs that are better for ibd, so they want to use engineered probiotics to treat IBD and prevent crc,by using synthetic biology. The rest of us were very interested in the project, and our Anhui University of Technology team actively asked them for details about their project, and they briefed them on the background and main contents of their project. The background of their project is that inflammatory bowel disease (IBD) is caused by inappropriate immune responses, which in general trigger a series of events that can disrupt the barrier when the immune system reacts excessively to the bacteria in the gut, eventually causing IBD when the immune imbalance persists without intervention. There is no cure for IBD at present,and the best treatment now is to use anti-inflammatory drugs such as TNF inhibitor treatment, but the patient's drug treatment effect is of huge difference.And it is ineffective to more than 50% of the patients . Probiotics are beneficial to the host of active microorganisms, colonization in the human intestinal tract, reproductive system, oral cavity and so they can produce the exact health effects of the microbial group.They have been beneficial to bacteria such as boulardii yeast used in clinical diarrhea treatment. The Tohoku University team aims to design a biological system for ANTI-IBD and CRC prevention through the use of engineered Probiotics. Because the concentration of NO in the intestinal tract of IBD is about 100 times than that of normal people, NO molecule acts as their inflammatory signaling molecule, and probiotic Escherichia coli (nissle 1917) is selected as their chassis organism. The project consists of two sets of devices, one of which is an anti-inflammatory device, which includes a sensor for detecting inflammatory signals, a high-efficiency enhancer, and an effector that secretes interleukin (IL-10); the second is an anti-cancer device, which is expressed through engineered probiotics, which is derived from a cross-flowered vegetable ( Cruciferous vegetables (myrosinase), which converts the natural component of Thio-glucoside (sinigrin) from a cross-flowered vegetable into a turnip (sulforaphane).The product of radish is a kind of organic molecule with anticancer activity, and it can inhibit oxidative stress (oxidative stress), so it can also inhibit the intestinal inflammatory reaction. In addition, they use cold-shock kill switches (cold-excited expression lysis and Maz-ef) to prevent their engineered bacteria from escaping into the environment and causing DNA contamination.


Members of the Northwestern University team introduced their project background that saline soils may affect the growth of crops such as wheat and rice. Because traditional saline soils are difficult and inefficient, they have decided to address this global challenge in new ways. Several parts of the bacterium are designed to reduce the concentration within the range. Their project is to modify potassium channels by using non-natural amino acid d-alanine,and they obtained a new channel protein, which allows K + to be considered in a high concentration of K + and allows Na + to be considered in a low concentration of K +. Because of the use of d-ala, a part of the introduction of unnatural amino acids into bacteria was established. They analyzed proteins and tested them by molecular dynamics simulations and quantum chemistry, and established mathematical models of the relationship between cells and salt concentrates. They will use patch clamps and a new method to test proteins and bacteria in the solution. After their cell experiments, they will use it for agricultural and water purification processes.


The project of Shandong University is about PHB an environmental bio-plastic Project. At the same time, we will carefully analyze the problems in the experiments and the modeling that are currently encountered in our project, so that we can better understand our project and excavate the parts that we may need to cooperate. In the course of the discussion, we talked about our understanding of synthetic biology, including its great potential for human benefit and the recent astonishing breakthroughs scientists have made. Then we showed and explained our project in depth, and they gave us some good suggestions, such as the improvements in cell secretion pathways that are practical, valuable and meaningful. We are really looking forward to our late-stage cooperation and exchanges with the United States to participate in the event of grand camping meetings.




  

Fig.10 Meeting venue




    6. Callobration with NEU-China

On August, 2018, our team established a connection with iGEM group of NEU-China-A and thus a couple of video conferences have been made so far. The two teams introduced each other's projects in detail; the project of NEU-China was to design a biological system against IBD and preventing CRC by using engineered probiotics. Since the concentration of NO in the intestines of IBD patients was about 100 times higher than that of normal people; therefore, NO molecules were chosen as inflammatory signals, and probiotics (Nissle 1917) were selected as chassis organisms. The project consisted of two sets of devices, one of which was an anti-inflammatory equipment, including a sensor for detecting inflammatory signals, an effective enhancer and an effector secreting interleukin 10 (il-10). Another one was an anti-cancer device,which is able to express a kind of myrosinase from cruciferous vegetables by virtue of engineering probiotics. Meanwhile, it can transfer glucosinolate, a natural ingredient in cruciferous vegetables into sulforaphane. Such a kind of product was a type of organic molecule with cancer-fighting ability and at the same time it could inhibit oxidative stress. Similarly, it could work against intestinal inflammation. In addition, we used cold shock kill switches (cold shock expression Lysis and maz-ef) to prevent our engineer bacteria from escaping into the environment and causing DNA contamination.


During exchange of project experience with each other, we learned that NEU-China-A had a little bit of a problem in one of the plasmid insertion experiments, so they asked us for help and wanted us to conduct the construction experiment of secreting the yebf-homoil10 plasmid.Our counterpart and we made it clear about what we were going to cooperate followed by three video meetings. NEU-China-A helped us carry out experiments on optimizing the conditions of prokaryotic expression of CSCA protein and purifying expression. In a similar way, we helped NEU-China-A perform fragment-linking experiment. NEU-China-A provided us with original plasmid of PCDF-Duet1 (dry powder tube), they taught us to overlap the secretion label Yebf (from BL21(DE3)DNA, GenBank: EF648003.1) with human-derived interleukin 10 (from BBa_K554004, Spring 2018 Distribution 21K 2018 Kit Plate 1), and required us to add the FLAG label at the N end of homoIL10 for subsequent protein detection. According to the requirements of our friend, we conducted the experiment on construction of secreting the plasmid Yebf-homoIL10. Having sequenced and verified the plasmid construction successfully, we mailed the no less than 100ng plasmid dry powder to them.


NEU-China-A helped us implement experiments on optimizing the conditions of prokaryotic expression of CSCA protein and purifying expression. Our friendship has thus been strengthened and the projects have also been pushed forward as the result of this collaboration, which is regarded as a successful cooperation by both of us.







    7. Biofilm Process Water Purification Laboratory

On September 8, 2018, our AHUT-China team visited the Biofilm Process Water Purification Laboratory of the College of Architecture and Engineering of Anhui University of Technology. The graduate student Xu Fan led us to visit the laboratory. The seniors introduced us to the principle of purifying sewage in the laboratory, which made us understand that relying on the microbial membrane fixed on the surface of the carrier to degrade organic matter has the characteristics of good effect and low technology and low cost.


Then we introduced our project to the seniors. The seniors said that many problems caused by CO2 also brought us many problems. Therefore, he has great hope for our project. At the same time, we have learned that the biomembrance process can not only treat sewage, but also can be applied to the treatment of organic gases. The pollutants in the organic waste gas are first contacted with water and dissolved in water, that is, diffused from the gas film into the liquid film; The organic pollutant components in the liquid film are diffused to the biofilm by the difference in concentration, and they are captured and absorbed by the microorganisms therein; the organic pollutants entering the microorganisms are decomposed as energy and nutrients in the metabolism of the microorganisms themselves. This provides us with some ideas on the combination of theory and practice.


Through a visit to the Biofilm Process Water Purification Laboratory in the afternoon, we learned about the biofilm treatment of sewage. At the same time, we also learned the necessity of our project. The impact of greenhouse gas CO2 cannot be underestimated. We also hope that our project can be applied to practice. The knowledge of biofilm processes in the treatment of organic waste gases has also given us some inspiration, and we may be able to use this knowledge when dealing with CO2.




Fig.11 Xu Fan, the head of the school, gave our senior to the laboratory (second from the left: Xu Fan)




Fig.12 Taking a photo in the biofilm purification laboratory)




    8. Collaboration with Harvard

iGEM competition is coming to an end, and a lot of teams have put out applications for various collaborations on the iGEM website. Fortunately, we got an opportunity to be part of the team Harvard (Fighting Stigma Against Synthetic Biology), and we also wanted to promote communication between us through the cooperation.

This year, Harvard wants to work with other teams to end the misunderstanding of synthetic biology. We found that human exposure to bacteria tends to have negative effects, which are considered as something dangerous. As an iGEM team, we understand that genetically engineered bacteria are largely untapped resources, helping us show the world the true potential of using such a bacteria for treatment, diagnosis, environment and so on.Harvard plans to release a series of articles to show all the cool things and germs the team is working on. Besides, they want introductions of other teams’projects, so we send ours to them on request.


Here is the introduction of our project. In the wake of the increasing greenhouse exerting more serious impacts on the global environment, the question of how to efficiently deal with CO2 is particularly critical. However, the traditional gas collection technology featured by high energy consumption and low efficiency is not yet mature enough. Meanwhile, it is these characteristics that have limited the development of itself.Our project is to obtain carbonic anhydrase (CA-2) with high thermal stability through computer simulation of the protein molecules expressed by carbonic anhydrase gene locus mutation, and import it into escherichia coli cells to achieve efficient collection of CO2.

We are honored to participate in this cooperation, and hope that through this channel we can reduce the misunderstanding of genetic engineering.






Fig.13 The mail we sent each other




    9 . Cooperation with Nanjing University

With the shortening of the time, our iGEM team encountered difficulties. The plasmid solution used in an experiment procedure in interlab was not effective after many times of cultivation, so the next experiment could not be carried out. We communicated the results with other iGEM teams. Nanjing-China of Nanjing university knew about it and then provided the bacteria liquid we needed. Our team members went to the school of life science of Nanjing university to obtain the bacteria liquid .


With the help of Nanjing-China, we successfully carried out the next experiment of Interlab, and finally achieved the success of it. We would like to express our hearty thanks to Nanjing-China for their help!


   10.NEFU-China

We contacted the iGEM team of Northeast Forestry University (NEFU-China) on August 2018, and our two teams gave each other some detailed descriptions of our projects.

NEFU modeling:
NEFU modeling: They store information in a yeast, and the time of information storage is the key to the case. The information storage time (a yeast growth time) needs to consider some parameters ,such as the initial inputs of α yeast and a yeast, the concentration of a-factor, and the expression efficiency of Bax gene. Firstly, partial correlation analysis is used to analyze the local sensitivity of the complex relationship between parameters and results, which provides a basis for accurate and efficient modeling and reliability analysis of simulation results. The results of sensitivity analysis showed that the secretion amount of α-factor and the growth time of a yeast had a higher sensitivity . Therefore, α- factor is refined into dry powder, which excludes the influence on the information storage of other interference factors such as the growth of α yeast . Secondly, since the main body of case is that the two kinds of yeast cultured in the medium ,and the growth of α yeast has some effects on the growth of a yeast should also be taken into account. So the competition model and the gun battle model are established. Finally, they provided a web-based, fully interactive modeling platform that provided information for wet experiments.

Model 1:
According to the case process we guess that : the amount of information stored (a growth time of yeast) is related to the initial inputs of two yeasts, The amount of α-factorsecreteby α yeast, and the promoting efficiency of the promoter. Therefore, the information storage is set as the output value, and the other parameters are set as the input values.Then the partial correlation coefficient is performed to verify the accuracy of the verification and which input is most relevant to the output.

Model 2:
The relationship between the time of information storage and the amount of α factor, time, promoting efficiency, the amount of yeast, and amount of alpha yeast was determined by model 1. They divided the experiment into two parts. The first part is that: a yeast and alpha yeast compete for growth without secretion of alpha factor. The second part is that: in the case of α-factor secretion, the two yeast growth for fighting, and the death rate of α yeast is the expression rate of Bax gene, and the expression rate of Bax gene is related to the start efficiency of the Fig2c promoter. In order to measure the efficiency of the start of the Fig2c promoter, the promoter efficiency of the promoter was measured by the amount of fluorescence by inserting the fluorescent protein gene of EGFP.













Through the above experimental process, we have established two mathematical models:
1)Competition model:










    The change trend of OD value of yeast with time was reviewed, taking the maximum value of the slope r1=r2










2) fighting model:





They putted in different proportions of yeast and calculated the information storage time by modeling. At the same time, the ratio of yeast can be predicted by different storage times. NEFU-China provided a web-based, fully interactive modeling platform that not only provided some information for their wet experiments, but also enabled future iGEM teams to build more efficiently based on our work.

In the laboratory,our team has simulated the exhaust gas ratio which can be found in literatures .The corresponding proportion of the gas was mixed manually and the gas was injected into water to prepare an unsaturated solution. The content of carbon dioxide in the solution was tested continuously according to the time of the gas entering, and this was used as the data source of our mathematical modeling.

First of all.By using MATLAB to conduct the correlation analysis of the experimental data,we found that the color readings (five dimensions: B, G, R, H, S) showed a certain linear correlation with the concentration of carbon dioxide.This conclusion is consistent with the other conclusion ,which obtains its conclusion by using lambert-beer's absorption law. That is, there is a certain relationship between the substance concentration and the color reading. Secondly, using the multiple regression of statistics to carry out regression analysis on the data, the relationship between the material concentration and the color reading (five-dimensional) is obtained, and the appropriate mathematical expression (or mathematical model) between them is determined as the empirical formula or regression equation.
A mathematical model for determining color readings and carbon dioxide concentration - a linear regression equation. Firstly, a linear regression model between carbon dioxide concentration and color reading is established. The residual of the model is large and the fitting effect is not good.

Considering establishing a nonlinear quadratic regression model.Using the rstool function modeling in the MATLAB statistical toolbox, and evaluating the pros and cons of the model by residual standard deviation and residual. In the final nonlinear quadratic regression model, the residual standard deviation is small, the prediction model is very good, and the residual of the model is reduced by an order of magnitude compared with the multiple linear regression model. Therefore, the linear quadratic regression model is better than the linear regression model. The comparison of the errors of the two models shows that the nonlinear regression quadratic equation has higher precision.

In the process of project communication with each other, we learned that they had a little trouble in modeling. It may be that Northeast Forestry University-China did not fully consider the influence of external factors on the experiment, which led to some errors in the model establishment. Through our tests, we found that the lethal efficiency of their calculations was wrong. After we found the problem, we told them in time and helped them improve the model.

The Northeast Forestry University iGEM team (NEFU-China) also helped us to test the safe reliability of our model. Through this cooperation, the friendship between our two teams was strengthened and the progress of the project was promoted. Both sides regard it as a fairly successful collaboration.
Thanks to the iGEM team of Northeast Forestry University (NEFU-China) for their help！