**16. β-glucosidases**

β-D-glucosidases hydrolyse soluble cellobiose and other cellodextrins with a DP up to 6 to produce glucose in the aqueous phase in order to eliminate cellobiose inhibition [13].

These enzymes have molecular weights ranging from 35 to 640 kDa, and they can be mono‐ meric or exist as homo-oligomers, as is the case β-glucosidase of the yeast *Rhodotorula minuta* [142]. Most β-glucosidases are glycosylated; in some cases, as that of the 300 kDa BGL from *Trametes versicolor*, glycosylation may be superior to 90%. Their optimum pH ranges from 3.5 to 5.5, and their optimum temperature ranges from 45 to 75 °C (3). β-D-glucosidase activ‐ ities can be measured using cellobiose, which is not hydrolysed by endoglucanases and exo‐ glucanases [13].
