rice husks [14], being the results different to each raw material.
In the present work, it was studied the effect of hemicellulose
and lignin on enzymatic hydrolysis of cellulose from brewer’s
spent grain (BSG), a lignocellulosic agro-industrial by-product
that has recently received considerable attention since it is cheap,
available in large quantities and has high carbohydrate content
[15].
BSG was initially pretreated before enzymatic hydrolysis to
obtain samples with different chemical composition. There are
several kinds of pretreatments able to disrupt the lignocellulose
structure. Dilute acid, for example, is a good alternative to
selectively remove the hemicellulose fraction generating a solid
residue basically composed by cellulose and lignin (cellulignin)
[7,16]. On the other hand, the use of dilute alkali is efficient for
lignin removal [7,17]. Consequently, a cellulose enriched material
can be produced by using these pretreatments in sequential
stages. Based on these facts, the BSG samples investigated in
this study were: (1) an untreated (in the original form); (2) cellulignin
(from dilute acid pretreatment) and; (3) cellulose pulp
(from sequential pretreatments using dilute acid and dilute alkali
solutions).