| Lignocellulosic Fraction |
Enzymes |
Location of action |
Mode of action |
E.C number |
| Cellulose |
Endo-1,4- β-glucanases
(EG) |
Cellulose (amorphous
regions) |
Attack the amorphous regions of the cellulose and produce glucose. |
3.2.1.4 |
| Cellobiohydrolases
(CBH)
(Exo-l,4-p-glucanase) |
Cellulose (crystalline
regions) |
Hydrolyze
β-1,4-glycosidic bonds from chain ends, producing cellobiose as the main product. |
3.2.1.91 |
| β-glucosidases (BGL) |
Cellobiose, cellodextrins |
Hydrolyze soluble
cellobiose and cellodextrins to glucose. |
3.2.1.21 |
| Hemicellulose |
Endo-xylanase |
Xylan main chain |
Hydrolyzes mainly interior β-1,4-xylose
linkages of the xylan backbone. |
3.2.1.8 |
| Exo-xylanase |
Xylan main chain |
Hydrolyzes the terminal β-1,4-xylose linkages releasing xylobiose. |
3.2.1.37 |
| β-Xylosidase |
Xylooligosaccharides |
Releases xylose from xylobiose and short chain xylooligo-saccharides. |
3.2.1.32 |
| α-Arabinofuranosidase* |
α- L-arabinofuranosyl compounds attached to the xylan main chain |
Hydrolyzes terminal nonreducing
α-arabinofuranose from arabinoxylans. |
3.2.1.55 |
| α-Glucuronidase* |
α- 1,2-linked glucuronic or 4-O-
methylglucuronic acid substituents attached to xylan main chain |
Releases glucuronic acid from glucuronoxylans. |
3.2.1.31 |
| Acetylxylan esterase* |
O-Acetil groups attached to the side ends of xylan main chain |
Hydrolyzes acetylester bonds in acetyl xylans, liberating acetic acid. |
3.1.1.6 |
| Ferulic acid esterase* |
feruloyl group on the arabinofuranosyl side chain attached to the terminal non-reducing xylose |
Hydrolyze the ester linkages between arabinose side chain residues and phenolic acids (ferulic acid). |
3.1.1.1 |
| Lignin |
Laccase (phenol oxidase) |
Phenolic compounds found in the lignin structure |
Oxidizes phenolic subunits of lignin. |
1.10.3.2 |
| Lignin peroxidase
Manganese peroxidase |
Aromatic compounds found in the lignin structure
Phenolic compounds found in the lignin structure |
Oxidation of benzilic alcohols, cleavage of
C-C bonds, cleavage of C-O bonds.
Oxidation of Mn2+ to Mn3+, which then binds to an appropriate ligand, diffuses from the enzyme, and, in turn oxidizes phenolic substrates. |
1.11.1.7
1.11.1.13 |
