Team:USP-Brazil
Genetic Switch for Bioproduction
Bioproduction is a process of great industrial interest that generates useful products through microorganisms. The most common system for control of the bioproduction are the use of chemical induction compounds (like IPTG and arabinose) that are, not only expensive, but also lacks fine control of induction. Our goal is to built a genetic circuit that can switch between two different states of activation with just a single input of blue LED light. The system was built in E.coli and works based on DNA-protein inhibition loops, recombinases capable to invert the DNA orientation of a promoter region and a light-responsive genetic circuit. In addition, fluorescent proteins such as GFP, RFP and YFP function as output for our circuit. We also aim to compare the efficiency between light-induced promoters to chemical-ones, by evaluating strength and leack. With our circuit, it is our hope that bioproduction can become more practical, controlled and economical.
Light is a fine, precise inductor, as the specificity of the signal is in the emissor, the wavelength and intensity, and in the receptor, in our case, a protein, that recognize a specific wavelength ortogonali. Besides that, light can be activated instantaneously, simply by turning on it’s source. To stop the induction, it’s not necessary to change the culture media or wash the culture, a process that can make some bioproduction impossible. Using light opens new possibilities for this industry.
We wanted to make bioproduction an optimized process, and in our research we learn that a switch will be useful to regulate expression of two different states. For example, to produce two different compounds switching back and forward between the two, to get to an optimum. Another example of this strategy is the use of switch to alternate between growth of the bacteria culture and production of the compound of interest. This allows testing different combinations of time of growth and production to get to a maximum yield like shown in this case.