Improving corn ethanol production using enzymes produced by solid-state fermentation

Adding enzymes such as proteases and cellulases to the corn ethanol production process allows further improvement of yields and have positive impact on downstream processing. Solid-state fermentation is an advantageous technology to produce numerous enzymes all at once. Depending on the combination of a substrate with a strain of microorganism, numerous enzymatic compositions were obtained, which comprised a wide range of hydrolytic enzymes with several different ratios. Various strains of fungi and several agricultural by-products were screened by using small-scale solid-state fermentation, in order to obtain an enzymatic composition which gave maximum effect on ethanol production from corn. By adding one selected composition to the SSF step of corn ethanol production, final ethanol concentration was enhanced by 1% to 2.5%, depending on the corn process conditions, and glycerol production was significantly reduced. Comparison with commercial products showed technical efficiency of enzymes produced by solid-state fermentation.