Industrial plants and traffic largely depend on exploitation of fossil fuels, however due to the global heating renewable energy sources are becoming more important. Bio-ethanol production from plant biomass is a promising option. Yeast Saccharomyces cerevisiae is appropriate microorganism for that because it is resistant to high ethanol concentrations. Unfortunately, S. cerevisiae is unable to metabolize pentose sugars that are abundantly present in plant material. Therefore, a lot of effort was invested in engineering genetically modified yeast.