Saccharomyces cerevisiae is an interesting micro-organism with good prospects in the future of yeast bioethanol production. In this study, both commercial and genetically modified S. cerevisiae were obtained from the local shops in Jeddah – Saudi Arabia and the Microbial Biotechnology Department – National Research Center (Dokki – Egypt) respectively, and incubated at 25 °C before being acclimatized for the conditions of this research.In this work, the impact of two different biochemical conditions (fermentation periods and nitrogen source concentration) on the growth, carbohydrates yields, and mainly bioethanol productivity from potato peels wastes (PPW) were studied in both species. PPW were used as a solo carbon source in this study with HCl acidic pre-treatment method. When studying the impact of fermentation periods, the best fermentation periods were found to be between the third and the fourth day. Additionally, the optimal nitrogen source concentration added to the fermentation medium was 2 g/L.This study concludes with some suggestions for future work in an attempt to reach commercial production of bioethanol at the lowest possible costs.