The use of residues from dairy industry is interesting because of the ease of acquisition and a relatively low cost. The objective of this study was to analyze ethanol production by the Saccharomyces fragilis varying the concentration of cheese whey powder (CWP) solution, initial pH and inoculum concentration using a factorial design technique; besides, semi-batch operations to add lactose was investigated. Statistical analysis was performed by ANOVA (p≤0.05). The concentrations of CWP solution and initial pH were significant in the fermentation medium for ethanol production. The optimum conditions were CWP solution 15 %, pH 5.0, inoculum concentration 5 % and a fermentation time of 18 h, and ethanol production reached 7.6 % (v/v). Additionaly, semi-batch... |