Nicotine detection model
To detect the existence of nicotine better, we made the first and second versions of system. Built on the pSB1C3 backbone, the former version contains a nicA2 promoter and a GFP gene, while the latter adds a T7 RNA polymerase gene and a T7 promoter in the middle of the former design, so as to enhance the expression of the fluorescence. Via experiments, we learnt that the activity of the nicA2 promoter is regulated by the concentration of nicotine, so we applied different concentrations on both designs for test, and used the results to build the following math models using MATLAB (R2018b). Correlation of the growth of first detection system with nicotine concentration
(A) Assumptions for the model:
1. The growth of the E. coli strain can be regarded as exponential within 4 hours
2. The concentration of nicotine in the environment is constant
3. The nicotine concentration is beyond the detection limit of the promoter
4. The fluorescent protein shows no significant sign of degradation
(B) Model used:
Where t stands for time; k is the assumed index of the bacteria growth, which is related to the concentration of nicotine; k_c is the index of fluorescence expression
(C)Time-varying fluorescence intensity under different concentrations of nicotine
(1) When the concentration of nicotine equals to 0.001 g/L, the fluorescence can be detected by the plate reader. With the passage of time, the fluorescence expression increases, which is significant at the 4-hour timepoint. The function is fitted as following:
Collaborations with other teams Collaboration with ZJU-China team.
The aspect about experimental problem: Because of the invalid homemade E. coli receptive state, we did experiments in the ZJU-China team’s laboratories by utilizing its commercial E. coli receptive state. This attempt provided enough opportunities for us to discuss the difference between the experiments, which exerted great advantage to solve such problems in the nest phase.
Before carrying out publicity activities, our team made comprehensive discussions with the ZJU-China team like establishing programs of activities, preparing materials, and decorating the venues.
Collaborations with social organizations Collaboration with Zhejiang Province Science Museum
We cooperated with Science museum and did some simple experiments in the venue stadium, which is not only appeals visitors, but also facilitates to promote the IGEM project and knowledge about synthetic biology.
Collaborations with Zhejiang Science and Technology Market
During the science and technology week held by Zhejing Science administrators, we collaborated with organizers. In that exhibition, we conducted a questionnaire survey as well as advertised the JGEM project, thus, enriching the program’s content.