Abstract
The potential for cofermentation of lipid and ethanol by Saccharomyces cerevisiae was investigated. Uniform design method and the SAS software were employed to analyze the effects of the selected fermentation conditions, including stirring speed, aeration rate, and glucose feeding rate, on the maximum yields of lipid and ethanol. Mathematical correlations about the influence of fermentation conditions on lipid and ethanol productions were established. The separated productions of lipid or ethanol from S. cerevisiae were 2.15 g/L or 31.93 g/L, respectively. Under the optimized conditions for cofermentation: glucose feeding rate 0 ml/h, stirring speed 210 rpm, and aeration rate 1 L/min, yield of 0.88 g/l lipid and 8.65 g/l ethanol could be achieved, simultaneously. The predicted results were verified by laboratory results. These results suggested that S. cerevisiae might be utilized as a promising microorganism for advanced biofuels production.
