Team:Evry Paris-Saclay
Abstract
During our working sessions, we explored a lot of areas, reviewing global concerns about our project in economics, law and ethics, but also in education and public engagement through scientific demonstrations and events focused around Science. In this way, we analysed the problems around Diabetes and possible ways to solve them using natural sweeteners. We also looked into the best way to provide it to people cheaply and efficiently using bioproduction.
With this in mind, we bioproduced D-Psicose, a rare, natural sugar and a sweetener with incredible properties such as inducing the metabolism of fats. D-Psicose can be produced by epimerization of Fructose either chemically or enzymatically. Chemical production isn’t efficient due to low yields and non-specific by-products. The enzymatic reaction is catalyzed by D-psicose 3-epimerase, an enzyme that exists in several organisms like Clostridium cellulolyticum. However, even if bioproduction is more specific than the chemical pathway, and the yields comparable, it would still be insufficient. For more efficient bioproduction, the enzyme must be modified to give better yields.
In our team we believe that a good project is one that considers people’s needs in order to answer them effectively. That’s why we involved Human Practices in the design and execution of our project, enhancing our bioproduction with a modular, biosensor based screening system.
Our biosensor-based screening system can sense the amount of Psicose present and produce an easily measurable, proportional fluorescent signal. This system is composed of a high affinity psicose transcription factor PsiR, extracted from species like Agrobacterium tumefaciens, specific inducible promoters and the fluorescent reporter mCherry. Using this tool on a large bank of enzymes, we can see that the more Psicose is produced the more fluorescence we will measure. This way, we are able to perform fast enzyme screening using the amount of fluorescence relative to the wild type enzyme. This avoids the use of low throughput and expensive screening techniques by large expensive devices. We also succeeded in designing and building a highly modular and efficient platform for biosensor engineering, the Universal Biosensing Chassis. This way, we can sense virtually any molecule as long as there is a transcription factor and its related promoter available to sense it.
