(421w) Modulation of Lignin Deposition/Composition Via Phytic Acid Mutation In Barley Straw Improves Sugar Release and Ethanol Production

Barley straw is an abundant agricultural byproduct from barley production. Biomass conversion research has developed processes for production of ethanol and other biofuels, but they remain costly primarily because of the intrinsic recalcitrance of biomass. Evaluation via fiber analysis, enzymatic hydrolysis, ethanol fermentation, thermogravimetric (TG) and differential thermogravimetric (DTG) analysis, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), we show here that the modulation of lignin deposition/formation in the second generation of barley straw can produce phenotypically normal plants that have reduced thermo-chemical, enzymatic, and microbial recalcitrance. This study reveal that mutation of the barley seed for low phytic acid (LPA) content decreases lignin content modestly, increases the syringyl:guaiacyl (S/G) lignin monomer ratio, thereby, enhances the ethanol yield by up to 21.1% using conventional biomass fermentation processes after the diluted acid-pretreatment. Therefore, this apparent reduction in the recalcitrance of mutant has the potential to significantly lower the processing costs for biomass fermentation-derived fuels and chemicals. Alternatively, such mutated barley straw lines in comparison to wild type should yield significantly more fermentation chemicals per hectare with the existing pretreatment process conditions.