Team:SDU CHINA/Results
The light-control part:
We desire to use the light to regulate the proportion of the bacteria dynamically. To evaluate the leakage in the light-control system, we characterized this part separately. First, we constructed the plasmids to characterize the blue light-activated protein YF1+FixJ and YF1+FixJ+PhIF. To tune ccaS expression, we constructed a sRBS library， which we used for characteriazation later.
Cells were cultured in the LB medium for 12 hours before inoculated in 12-well plates in M9 medium whose carbon source is glucose. The figure shows the green fluorescent intensity of E. coli under light of different wavelengths.
The combination of the light-control part and the quorum sensing part:
After combining the light-control part and the quorum-sensing part, we characterized it to verify the compatibility between the components in these two systems.
Cells were cultured in the LB medium for 12 hours before inoculated in 12-well plates in M9 medium whose carbon source is glucose. The figure shows the green fluorescent intensity of E. coli under the lights of different wavelengths.
Light-controlled bacterial co-culture system:
Finally, we combine the two above parts with the toxin and antitoxin part to construct the light-control bacterial co-culture system successfully.
We got the data through enzyme-labeled instrument and analyzed it to get the figure.The y-axis is the number of cells, and the x-axis is fluorescence intensity. There are two kinds of E.coli . One kind of E.coli carries sfGFP on the genome. The other kind of E.coli carries RFP on the genome. Cells were individually cultured in the LB medium for 12 hours before being commonly inoculated in 12-well plates in LB medium. In the first 13 hours. Figure 3. shows the different fluorescent intensity of E.coli under light of 640-650 nm wavelength for the first 13 hours and light of 460-465 nm wavelength for the next 12 hours. Figure 4.shows the different fluorescent intensity of E.coli under light of 640-650 nm wavelength for the first 13 hours and light of 530-535 nm wavelength for the next 12 hours. We can see that after 12 hours of blue light exposure, the number of E. coli bacteria carrying RFP dropped by half. After 12 hours of green light exposure, the number of E.coli carrying GFP decreased by half.
