There is an increase in researches to create alternative fuels through the use of biomass and agroindustrial lignocellulosic residues. The present study proposes the use of rice bran as source of energy with the potential to enhance bioethanol production. Using different concentrations of cells (1-5 g.L–1) and rice bran (2.5-7.5 g.L –1) with Saccharomyces cerevisiae, a factorial design 22 was carried out. The nutrient source provided by rice bran affects the substrate conversion in product (Yp/s) response in a quadratic form, but its linear form showed no significant effect (α = 0.05). When it comes to means, the best results were obtained for 12 h and for fermentation medium 2 (23.320 g.L–1 of ethanol), which contained the highest rice bran concentration and the lowest initial cell concentration. Medium 3, consisting of 2.5 g.L–1 and 5 g.L –1 of rice bran and cells, respectively, showed the lowest K s (4.434 g.L–1).
