Greater energy (temperature and pressure), and or quantity of enzymes (cellulases), are needed to hydrolyse cellulose
that is embedded within lignin. In addition to blocking the liberation of sugars from cellulose and adhering to hydrolytic
enzymes, lignin may also release aromatic compounds that inhibit fermentation. Modifying lignin content, composition,
hydrophobicity and cross-linking can improve the enzymatic hydrolysis of cell walls.