Principles of biomass pretreatments under acidic conditions
- Colorado State Univ., Fort Collins, CO (United States)
Common biomass pretreatments for enzymatic hydrolysis of cellulose under acid conditions include dilute acid, autohydrolysis and organosolv, all at elevated temperatures, and ensiling under ambient conditions. Xylan, the major hemicellulose component of plants, occurs naturally in a partially acetylated form. Lignin is also convalently associated with hemicellulose. Simple removal of the acetyl residues enhances hemicellulose and cellulose accessibility by hydrolytic enzymes. Cleavage of side chains from hemicellulose by action of the acidic environment affects the lignin matrix surrounding the cellulose microfibril because the covalent hemicellulose-lignin complex is made free. The lignin is not necessarily removed, but rendered extractable. The cellulose is thereby more accessible to the synergistic action of the components of fungal and bacterial cellulase complexes. The degree of acetylation of xylan is inversely related to the rate of enzymatic hydrolysis of the hemicellulose. Acetylxylan esterase (AXE) action may thereby by prerequisite to that of other enzymes in natural biodegradation processes.
- OSTI ID:
- 141968
- Report Number(s):
- CONF-930304--
- Country of Publication:
- United States
- Language:
- English
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