Some of the challenges of fermentation processes are the high temperatures and anaerobic enviroment inside the vats where the fermentation occurs, usually by the action of the yeast S. cerevisiae which can grow in full anaerobic conditions, futhermore, this yeast is not thermotolerant and can't grow in temperatures above 32Cº, in this work we compare 6 different species of yeasts to try and determine the genetic mechanisms behind anaerobic growth and thermotolerance.