The lignin present in steam pretreated softwood binds enzymes and limits cellulose accessibility

► The work compared two major influences of lignin during the enzymatic hydrolysis of steam pretreated Douglas-fir. ► The overall inhibitory effect of lignin is dependent on enzyme loading and cellulose accessibility. ► At low enzyme loading, lignin's influence on both limited cellulose accessibility and unproductive binding were at play. ► The impact of lignin's enzyme binding was also dependent on how accessible the cellulose was. ► The cumulative effect of lignin is thus, ultimately dependent on overall cellulose accessibility.