Thales H. F. Costa

Mapping of Cell Wall Components in Lignified Biomass as a Tool to Understand Recalcitrance

Lignocelulosic biomass is recalcitrant to enzymatic digestion because terrestrial plants develop an efficient manner to grow upward and resist the microbial degradation of the polysaccharides contained in their cell walls. The complex cell ultrastructure, varied tissues, and the composite characteristic of the cell walls are among the several factors explaining the recalcitrance of lignified plants. Mapping the macromolecular components in the cell walls has proved to be useful to understand the varied recalcitrance of different biomass tissues. Available data indicate that lignin and hemicellulose greatly affect the final digestibility of the lignocellulosic materials. Removal of these components from the cell walls with varied pretreatments or even using lignin- and/or hemicellulose-depleted plants indicate that a critical characteristic of the cell wall to be digestible is to present most as possible available cellulose. This chapter revises some basic information on cell wall structure and advance in the knowledge compiling information on the mapping of cell wall components by several techniques and showing that the removal of cellulose encapsulating components is a key factor to increase cell wall porosity and digestibility by hydrolytic enzymes.