Bisulfite Pretreatment Improves Enzymatic Digestibility of Oil Palm Empty Fruit Bunch and Poplar Through Changing Its Structure and Lignin Distribution.

This paper investigated the changes in anatomy, ultrastructure and lignin distribution of oil palm empty fruit bunch (EFB) by bisulfite pretreatment. It was found that after bisulfite pretreatment, a large number of pores formed in the cell walls, and the removal of part of the lignin in the cell wall corner, partial middle layer, and other locations made the tissue structure of the EFB looser, which uncovered cellulose and broke the steric hindrance of cellulase access to cellulose in EFB, and also weakened the negative influence of lignin on cellulase. The changes can greatly contribute to the improvement of enzymatic hydrolysis after bisulfite pretreatment, which is consistent with the increased saccharification efficiency of the pretreated EFB. Poplar was also used to compare the differences and similarities between non-wood and wood materials.