2007 Volume 8 Issue 4 Pages 257-265
The possibility of generating renewable bio-fuel energy through ethanol fermentation of kitchen refuse by Saccharomyces cerevisiae ATCC 26602 was established in this work. The acid-tolerant yeast S. cerevisiae ATCC 26602 was selected from among four S. cerevisiae strains as the best ethanol fermentation agent for kitchen refuse medium. The optimal kitchen refuse medium for ethanol production had a glucose concentration of only 12% (w/v) and consisted of saccharified kitchen refuse. Additional nitrogen supplementation was not necessary. A maximal ethanol concentration of 59.38 g/L with a 0.50 ethanol yield (YP/S) was obtained with the optimal medium composition in flask culture under shaking and without pH control. No significant difference was observed in ethanol production and glucose consumption between sterilized, pasteurized and non-sterilized kitchen refuse medium samples. A final ethanol concentration of 50.22 g/L, corresponding to a 0.42 ethanol yield (YP/S), was obtained using a 20-L bioreactor with a working volume of 12 L under non-sterilized conditions at an agitation rate of 100 rpm at 30°C for 18 h. Therefore, the ethanol fermentation of kitchen refuse under non-sterilized conditions by S. cerevisiae ATCC 26602 may offer an economical alternative for bio-fuel production in industrial applications.