Sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust enzymatic saccharification of hardwoods

Abstract

This study demonstrates sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust bioconversion of hardwoods. With only about 4% sodium bisulfite charge on aspen and 30-min pretreatment at temperature 180[degrees]C, SPORL can achieve near-complete cellulose conversion to glucose in a wide range of pretreatment liquor of pH 2.0–4.5 in only about 10 h enzymatic hydrolysis. The enzyme loading was about 20 FPU cellulase plus 30 CBU Beta-glucosidase per gram of cellulose. The production of fermentation inhibitor furfural was less than 20 mg/g of aspen wood at pH 4.5. With pH 4.5, SPORL avoided reactor corrosion problem and eliminated the need for substrate neutralization prior to enzymatic hydrolysis. Similar results were obtained from maple and eucalyptus.

Keywords

Sulfite, bisulfite, pretreatment, enzymatic hydrolysis, recalcitrance, lignocellulose, saccharification, hardwood, biomass, fermentation inhibitors, size reduction, SPORL, enzymes, biotechnology, industrial applications, biodegradation, cellulose, hydrolysis, glucose, fermentation, biomass energy, energy consumption, sugars, wood chips, aspen, maple, eucalyptus, cellulase, feedstock, populus, bioconversion, chemical utilization, biorefining, wood extractives, chips, Acer, sodium bisulfite, sulfite liquors, beta glucosidase

Citation

Wang, G. S.; Pan, X. J.; Zhu, Junyong; Gleisner, Roland; Rockwood, D. 2009. Sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust enzymatic saccharification of hardwoods. Biotechnology progress. Vol. 25, no. 4 (2009): pages 1086-1093.