The yeast saccharomyces cereviceae still remains the major
industrial ethanol producer. Efficient industrial production
requires a rapid fermentation leading to high ethanol
concentration, therefore a yeast strain must have a good
specific growth rate and specific ethanol production rate at
high osmotic pressure and ethanol concentration. This goal
is not easy to achieve since many parameters during batch
fermentation can cause the decrease of specific rate of
growth and inhibition can be caused either by product or
substrate (Bai. et al., 2008). Many strategies have been
explored to improve ethanol production.