Brazilian Journal of Chemical Engineering
On-line version ISSN 0104-6632
BARCELOS, C. A.; MAEDA, R. N.; BETANCUR, G. J. V. and PEREIRA JR., N.. Ethanol production from sorghum grains [Sorghum bicolor (L.) Moench]: evaluation of the enzymatic hydrolysis and the hydrolysate fermentability. Braz. J. Chem. Eng. [online]. 2011, vol.28, n.4, pp. 597-604. ISSN 0104-6632. http://dx.doi.org/10.1590/S0104-66322011000400005.
The production of ethanol from sorghum grains was investigated in the present work. Initially, starch enzymatic hydrolysis was investigated using commercial α-amylase and glucoamylase, considering particle size, solid:liquid ratio and enzyme load as variables. The hydrolysate, in the best conditions (73 U of α-amylase/g grain and 1150 U glucoamylase/g grain), contained glucose at a concentration of approximately 250 g/L, which was fermented to produce ethanol in a bioreactor in batch mode. Using an industrial strain of Saccharomyces cerevisiae, the maximum ethanol concentration produced was roughly 106 g.L-1 in 24 h of fermentation, resulting in a volumetric productivity of 4.4 g.L-1.h-1 and a product yield based on the substrate consumed (0.499 g.g-1) close to the theoretical.
Keywords : Sorghum Grains; Enzymatic Hydrolysis; Ethanol; Fermentation; Saccharomyces cerevisiae.