Enhancing the Yield of Bioethanol from the Lignocellulose of Oat Hulls by Optimizing the Composition of the Nutrient Medium

Abstract

The optimum composition is determined for a nutrient medium corresponding to the maximum yield of bioethanol during the alcohol fermentation of the enzymatic hydrolyzate of lignocellulosic material, produced by treating oat hulls with a diluted solution of nitric acid in trial production. The biotechnological steps of saccharification and fermentation are performed using commercially available enzymatic preparations CelloLux-A and BrewZyme BGX, plus a strain of Saccharomyces сerevisiae Y-1693 (VKPM) that is resistant to inhibitors from hydrolyzates. The composition of a nutrient medium that produced a bioethanol yield which was 89.9% of the theoretical one (8.4% higher than the native hydrolyzate) is found to have a 1.82 g/L concentration of ammonium sulfate, a 0.98 g/L concentration of potassium monophosphate, and a 6.47 g/L concentration of yeast extract.