9.3.1.2 Exoglucanases (Cellodextrinase or 1,4-β-D-Glucan
Glucanohydrolases, EC 3.2.1.74) and Cellobiohydrolases
(Exo-1,4-β-Glucanases or 1,4-β-D-Glucan Cellobiohydrolases)
(EC 3.2.1.91)
Exoglucanases hydrolyze the cellulose chains (mostly cellobiose) from the reducing
and non-reducing ends. As a result of this, the reducing ends are rapidly released, but
no significant change occurs in the polymer length (Zhang et al. 2006). At the end of
the hydrolysis, they produce glucose (glucanohydrolase) or cellobiose
(cellobiohydrolase) as the final product (Carrillo-Reyes et al. 2016). Figure 9.5
includes some samples of exoglucanase producing microorganisms (Park et al.
2001; Tuohy et al. 2002).
9.3.1.3 β-Glucosidases (Cellobiases or β-D-Glucoside Glucohydrolase,
EC 3.2.1.21)
β-glucosidases are enzymes that turn cellodextrin and cellobiose into glucose. Due to
the reduced final product inhibitions of the endoglucanases and exoglucanases, the
hydrolysis of the cellulose is generally increased by adding these cellobiases
Fig. 9.5 Lignocellulosic biomass degrading enzyme group
268
T. Karaytuğ et al.
Glucanohydrolases, EC 3.2.1.74) and Cellobiohydrolases
(Exo-1,4-β-Glucanases or 1,4-β-D-Glucan Cellobiohydrolases)
(EC 3.2.1.91)
Exoglucanases hydrolyze the cellulose chains (mostly cellobiose) from the reducing
and non-reducing ends. As a result of this, the reducing ends are rapidly released, but
no significant change occurs in the polymer length (Zhang et al. 2006). At the end of
the hydrolysis, they produce glucose (glucanohydrolase) or cellobiose
(cellobiohydrolase) as the final product (Carrillo-Reyes et al. 2016). Figure 9.5
includes some samples of exoglucanase producing microorganisms (Park et al.
2001; Tuohy et al. 2002).
9.3.1.3 β-Glucosidases (Cellobiases or β-D-Glucoside Glucohydrolase,
EC 3.2.1.21)
β-glucosidases are enzymes that turn cellodextrin and cellobiose into glucose. Due to
the reduced final product inhibitions of the endoglucanases and exoglucanases, the
hydrolysis of the cellulose is generally increased by adding these cellobiases
Fig. 9.5 Lignocellulosic biomass degrading enzyme group
268
T. Karaytuğ et al.