Part:BBa_K3081053

Quorum Sensing CRISPRri System Enables Spatial-level Growth Control and Ultrasensitive Autoregulation of Growth

Hence, based on the well-characterized growth control system, we constructed a quorum sensing CRISPRri system (qs-CRISPRri) to realize smart regulation of bacterial overall states.

A time-scale quorum sensing system can be transformed to spatial-level through a donor/receiver system (Figure 7). The donor cells, which merely express and release AHL, would activate the GFP expression of receiver cells through AHL diffusion. This is validated on the agar plate, by dropping the donor cells in the center and receiver cells around them with different distances. We found a progressive decrease in fluorescence as the receiver cells locate farther from central AHL donor.

Figure 1.The donor-receiver split quorum sensing system of CRISPRri system. Upper figure is the gene circuit of donor and receiver cells of qs-CRISPRri system. For the figure below, a donor-receiver split quorum sensing GFP system enables fluorescent intensity control on spatial scale. Left figure is the sketch map of how donor and receiver bacteria is dropped onto the agar plate. Right figure is the real picture of agar plate under illumination of blue light. The location of the white arrow is the donor cells. Receiver cells are marked by number one to six.

In this part, we can use golden-gate assembly to change the sgRNA sequence, in order to target different sites on bacterial genome. We mainly used M+ (BBa_K3081054) for the demonstration of qs-CRISPRri system. For more detailed information, see BBa_K3081054.

Reference:

[1]Weiqian Zeng, et al. Rational Design of an Ultrasensitive Quorum-Sensing Switch. ACS Synthetic Biology 2017 6 (8), 1445-1452.

[2]Y. Soma, T. Hanai. Self-induced metabolic state switching by a tunable cell density sensor for microbial isopropanol production. Metabolic Engineering 30 (2015) 7–158.