Team:Valencia/Project/Objectives

1. - Construction of a system consisting of Liquid Culture Calorimeter (LCC): a calorimeter with a thermocouple inside allowing microbial culture. The system should be able to maintain temperature around 28 ºC and record it during the experiment with a precision of ± 0.1 ºC.

The idea of working with thermogenin was not new. However, most experiments we have read about dealt with microcalorimeters and measured heat –rather than temperature- production. We were not able to find any information on whether this would lead to a temperature increase that could be recorded. If heat was produced in an Erlenmeyer flask, it would rapidly dissipate. Therefore, not only did we need our culture to heat up, but our project also required to have some kind of system where we could detect this variation in temperature. There’s where the idea of the Liquid Culture Calorimeter saw the light. This should be a system able to maintain temperature within a yeast-suitable rank during several hours, allowing the culture to grow inside.

2. – Demonstration that thermogenin-expressing yeast strains can heat their own broth medium.

Although it would have been easier to work with some prokaryote such as E. coli, we had two main reasons for choosing S. cerevisiae. On the one hand, we needed an organism with mitochondria, where thermogenin could carry out its function. On the other hand, we had some lab experience with yeast and some of us hate E.coli for some reason.

We contacted a researcher who has a long experience with yeasts expressing thermogenin, Dr. Eduardo Rial, from CIB, in Madrid. He was glad to help us and kindly provided us with four S. cerevisiae strains he was working with, which perfectly fulfilled the requirements of our project.

3. – Implementation of a regulatory system through genetic engineering of yeast strains allowing them to maintain the temperature of the medium around the wanted interval.

This system should have two switches: a lower limit under which thermogenin should start to be produced, and an upper one, where the activity of thermogenin would be suppressed. (Coming soon)