Reutilization of enzymes for saccharification of lignocellulosic materials

Enzymic hydrolysis of steam-exploded wheat straw is initially a fast process which gradually slows down. Since the cellulolytic enzymes account for 60% of the processing costs incurred during saccharification of lignocellulosics, recirculation of these enzymes is clearly necessary. It is demonstrated that the cellulolytic enzymes have a high affinity for the remaining lignin. Only 50% of the added enzymes are free in solution after almost complete hydrolysis of the straw polysaccharides. Elution of the enzymes from the lignin can result in a total enzyme recovery of up to 90%. However, it is questionable whether elution of enzymes from the lignin is economically feasible as a technical process.