Enzyme management in the Iotech process.
In the Iotech process, steam explosion of wood chips potentials hydrolysis of the cellulose by enzymes. A small portion of the exploded wood is used as substrate for the production of enzymes for hydrolysis of the remaining wood. Explosions conditions degrade some of the hemicellulose, creating factors (probably related to furfural) that impair enzymatic hydrolysis and destabilized the cellulases. Fortunately, simple washing with water permits more rapid hydrolysis while enzyme stability is greatly improved. Enzymes can be recovered from the hydrolysis residue by adjusting the pH to neutrality, and additional enzymes from hydrolysis filtrate can be adsorbed on fresh exploded wood en route to hydrolysis. A simple mass balance calculation shows proportions of various activities in a mix of fresh and recycled enzymes.
Sinitsyn
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AP
Rensselare Polytechnic Institutre, Troy, New York 12181, USA.
Bungay
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HR
Clesceri
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LS