Effect of pretreatment on saccharification of sugarcane bagasse by complex and simple enzyme mixtures

• Published in: Bioresource technology Vol. 148; pp. 105 - 113
• Main Authors: Harrison, Mark D., Zhang, Zhanying, Shand, Kylie, O’Hara, Ian M., Doherty, William O.S., Dale, James L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2013
• Subjects: Acidification; Bagasse; beta-Glucosidase - pharmacology; Biomass; Carbohydrate Metabolism - drug effects; Cellulase; Cellulase - pharmacology; Cellulose - metabolism; Conversion; Enzymes; Glucan; Glycerol; Glycerols; Hydrolysis; Microscopy, Electron, Scanning; Pilot Projects; Pretreatment; Recombinant Proteins - pharmacology; Saccharification; Saccharum - drug effects; Saccharum - metabolism; Sodium Hydroxide - pharmacology; Solutions; Spectroscopy, Fourier Transform Infrared; Steam; Sugarcane; Sulfuric Acids - pharmacology; X-Ray Diffraction; Glycerol; Pretreatment; Cellulase; Sugarcane; Bagasse
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.08.099

•Mineral acid, soda, and glycerol/HCl pretreatments of sugarcane bagasse compared.•Glycerol/HCl residue easily hydrolysed by low dosages of simple enzyme mixtures.•Maximum glucan conversion was obtained with glycerol/HCl pretreatment.•NaOH residue achieved optimal saccharification at low commercial enzyme dosage. Saccharification of sugarcane bagasse pretreated at the pilot-scale with different processes (in combination with steam-explosion) was evaluated. Maximum glucan conversion with Celluclast 1.5L (15–25FPU/g glucan) was in the following order: glycerol/HCl>HCl>H2SO4>NaOH, with the glycerol system achieving ∼100% conversion. Surprisingly, the NaOH substrate achieved optimum saccharification with only 8FPU/g glucan. Glucan conversions (3.6–6%) obtained with mixtures of endo-1,4-β-glucanase (EG) and β-glucosidase (βG) for the NaOH substrate were 2–6 times that of acid substrates. However, glucan conversions (15–60%) obtained with mixtures of cellobiohydrolase (CBH I) and βG on acidified glycerol substrate were 10–30% higher than those obtained for NaOH and acid substrates. The susceptibility of the substrates to enzymatic saccharification was explained by their physical and chemical attributes. Acidified glycerol pretreatment offers the opportunity to simplify the complexity of enzyme mixtures required for saccharification of lignocellulosics.