Treating maize plants with benzohydrazide increases saccharification of lignocellulose: A non-transgenic approach to improve cellulosic ethanol production

Cellulosic ethanol production will decrease our dependence on fossil fuels, positively impacting global warming, energy security, and urban pollution. In the last few years, our group has screened a few enzyme inhibitors of the phenylpropanoid pathway. We have shown that when some enzyme inhibitors are sprayed in young plants, they increase the lignocellulose saccharification in the long term at the workbench scale. Here, we screened five aromatic compounds for their ability to improve the saccharification of maize plants. Benzohydrazide increased saccharification in a broad range of concentrations in growth-room experiments, and it was selected for field-scale assays. At 20 g ha−1 (500 μM, 300 L ha−1), benzohydrazide increased by 33 and 46%, respectively, the saccharification of lignocellulose from maize leaves and stems. When the lignocellulose biomass of maize plants, sprayed with benzohydrazide or not, was submitted to hydrogen peroxide–acetic acid delignification pretreatment, benzohydrazide increased the saccharification by up to 76%. Benzohydrazide did not significantly affect any other biometric (length or fresh and dry weights) or biochemical (lignin, monolignols, structural hydroxycinnamates) parameters assessed. In brief, benzohydrazide could be used to improve saccharification in agroenergy crops.