Team:BIT-China/Judging

From 2014.igem.org

project

Parts
COOPERATION

1. BIT-China for Tianjing

Click on the link to see the appropriate wiki section in the wiki of Tianjing

Measurement of parts

BIT-China collaborated with Team Tianjin in the measurement of their parts.

They send their sample of K1361007 to us, in which CsgA, the major subunit of curli fiber modified by twin 7Xhis tag, is under control of a strong constitutive promoter BBa_J23100. And the K1361007 was arrived in company with a parallel part where BBa_J23104, a relatively weaker promoter, replaced the BBa_J23100. In order to find the better fit of promoter, we measure the cell growth curve of each part and Bradford protein assay was adopted to monitor the total quantity of secrete protein in matrix.

Cell growth curve of BBa_J23100 and parallel that a relatively weaker promoter was used to control the CsgA secrete level.

This figure shows the absorbency of secrete protein in culture between K1361007 and parallel. No significant divergence was found.

2.Tianjing for BIT-China

Model of MIN system

Tianjin Team use a classical model, density-dependent growth model, for helping BIT-China to stimulate population of E.coli growing. Also they use some other differential equations to describe the dynamic change of AHL, LuxR proteins and MinC proteins. The total equations are as follows:



Then they use these equations to simulate the function of MIN system. The results are shown as figure 1 and figure 2.



Figure 1. The dynamic change of cell number and total number of LuxR proteins. After a sharp increase, the cell stopped multiplying themselves. With the growing of E.coli, the total number of LuxR proteins also increases. The initial value of cell number we set is 3000.



Figure 2. The dynamic change of MinC proteins and AHL signal. The AHL decrease very quickly with the growth of E.coli. And when AHL comes to the threshold value, the repression of MinC is removed. So after some time the MinC proteins increase quickly and the cell division process is inhibited.