Monday, May 4, 2009
9-33
Influence of nutrients supplementation on ethanol batch production rates
Alessandra M. dos Santos, Joćo Nunes de Vasconcelos, and Renata M. R. G. Almeida. Technology Center, Federal University of Alagoas, Campus A. C. Simoes, Via Br 104-North, Km 97, Tabuleiro dos Martins, Maceio, Brazil
Ethanol is a renewable energy source produced through fermentation of sugars unlike the fossil fuels. During fermentation of Saccharomyces cerevisiae, the activities of the microorganisms closely respond to changes in the environmental conditions, which are accompanied by variations in the metabolic behavior of the microorganisms. The nutritional necessities of the yeast during alcoholic fermentation influence the cellular growth and the efficiency of ethanol production. The aim of this work was study the influence of nutrients supplementation of the cane molasses and sugar cane musts on the batch ethanol production. Batch fermentation experiments were carried out with sucrose of cane molasses and sugar cane musts as the sole carbon source for S. cerevisiae. The nutrients supplementation was done with three commercial nutrients (A, B and C) with different compositions. Fermentation flasks were shaken in the incubator at 200 rpm and 32ºC. The musts were analyzed to determine the amount of each nutrient before the supplementation. Samples were withdrawn and after analysis production rates like fermentative efficiency, ethanol productivity and yield were calculated. For cane molasses must, it was found that concentrations of nutrients that maximize the efficiency and productivity in the fermentation process were: 0.20 g of A/L; 0.50 g of B/L and
0,30 g of C/L of juice. And for sugar cane must these concentrations were: 0.50 g of A/L; 1 g of B/L; and 2 g of C/L. The results consequently provide a better understanding of nutrients supplementation effects on the cell activities for further development of the process.
0,30 g of C/L of juice. And for sugar cane must these concentrations were: 0.50 g of A/L; 1 g of B/L; and 2 g of C/L. The results consequently provide a better understanding of nutrients supplementation effects on the cell activities for further development of the process.