Elucidating the Interactive Impacts of Substrate-Related Properties on Lignocellulosic Biomass Digestibility: A Sequential Analysis

A lack of insight into interactive effects among substrate-related factors holds back the determination of dominant factors in efficient sugar conversion. Herein, 13 factors defining compositional and physicochemical properties of lignocellulose pretreated by dilute acid/base and enzymes were analyzed through an innovative sequence of correlation analysis, principle component analysis, multiple linear regression, and multiscale statistical validation. Results showed that the lignin content, cellulose content, and O/C ratio principally affected enzymatic hydrolysis. The dominant role was played by the lignin content due to its major recalcitrance providing to biomass and concomitant impacts on surface lignin and porosity properties. The structural features of lignin played a less pronounced role with high lignin content that remained. Besides, the sequential analysis revealed different inhibition mechanisms for glucan and carbohydrate conversion, that is, nonproductive binding of enzymes and steric hindrance of lignin, respectively. The established weighing order of interactive factors enlightened more efficient pretreatment strategies.