Laccase pretreatment for enhancing microwave-assisted alkaline extraction of hemicellulose from bagasse

Abstract

Laccase pretreatment is a promising approach to degrade lignin polymer for enhanced hemicellulose extraction from bagasse. A Box-Behnken design was employed to optimize microwave-assisted alkaline extraction of hemicellulose with the aim of maximizing the hemicellulose extraction yield. The effect of laccase pretreatment on the structural characteristics of the bagasse hemicellulose was studied with scanning electron microscopy and the Brunauer-Emmett-Teller method. The results showed that the lignin content of the bagasse decreased by 7.9% and the specific surface area increased by 95.9% after pretreatment with 160 U/g laccase for 6 h. The hemicellulose extraction yield was 88.7% under the optimum conditions of 8% NaOH, 50 min, and 900 W. The interaction between the NaOH concentration and extraction time, and between the extraction time and microwave power significantly affected hemicellulose extraction from the bagasse. Overall, the laccase pretreatment was beneficial to extraction of hemicellulose from bagasse using a microwave-assisted alkaline solution.