Vincent S. Chang and Mark T. Holtzapple investigated the factors affecting the enzymatic reactivity of poplar wood. They treated the wood with peracetic acid, potassium hydroxide, and ball milling to create 147 model lignocelluloses with varying lignin, acetyl, and crystallinity levels. An empirical model was developed to describe how these three properties influence enzymatic hydrolysis. The study found that lignin content and crystallinity have the greatest impact on biomass digestibility, while acetyl content has a minor effect. Lime treatment was shown to remove all acetyl groups and a moderate amount of lignin, slightly increasing crystallinity, with lignin removal being the main benefit of this treatment. Lignocellulose is the most abundant biomass that can be converted into liquid fuels through enzymatic hydrolysis and microbial fermentation. Due to its water insolubility, biomass conversion processes require direct contact between enzymes and substrates. Pretreatments are necessary to improve biomass digestibility by altering structural features. Modeling the role of structural features in determining digestibility allows for the prediction of enzymatic digestibility and the design of more effective pretreatments. Previous studies have focused on lignin content and cellulose crystallinity as key factors affecting digestibility. This study provides a summary of the relationships between biomass structural features and digestibility.Vincent S. Chang and Mark T. Holtzapple investigated the factors affecting the enzymatic reactivity of poplar wood. They treated the wood with peracetic acid, potassium hydroxide, and ball milling to create 147 model lignocelluloses with varying lignin, acetyl, and crystallinity levels. An empirical model was developed to describe how these three properties influence enzymatic hydrolysis. The study found that lignin content and crystallinity have the greatest impact on biomass digestibility, while acetyl content has a minor effect. Lime treatment was shown to remove all acetyl groups and a moderate amount of lignin, slightly increasing crystallinity, with lignin removal being the main benefit of this treatment. Lignocellulose is the most abundant biomass that can be converted into liquid fuels through enzymatic hydrolysis and microbial fermentation. Due to its water insolubility, biomass conversion processes require direct contact between enzymes and substrates. Pretreatments are necessary to improve biomass digestibility by altering structural features. Modeling the role of structural features in determining digestibility allows for the prediction of enzymatic digestibility and the design of more effective pretreatments. Previous studies have focused on lignin content and cellulose crystallinity as key factors affecting digestibility. This study provides a summary of the relationships between biomass structural features and digestibility.