title: Effects of enzyme loading and β-glucosidase supplementation on enzymatic hydrolysis of switchgrass processed by leading pretreatment technologies.
abstract: The objective of this work is to investigate the effects of cellulase loading and β-glucosidase supplementation on enzymatic hydrolysis of pretreated Dacotah switchgrass. To assess the difference among various pretreatment methods, the profiles of sugars and intermediates were determined for differently treated substrates. For all pretreatments, 72 h glucan/xylan digestibilities increased sharply with enzyme loading up to 25mg protein/g-glucan, after which the response varied depending on the pretreatment method. For a fixed level of enzyme loading, dilute sulfuric acid (DA), SO(2), and Lime pretreatments exhibited higher digestibility than the soaking in aqueous ammonia (SAA) and ammonia fiber expansion (AFEX). Supplementation of Novozyme-188 to Spezyme-CP improved the 72 h glucan digestibility only for the SAA treated samples. The effect of β-glucosidase supplementation was discernible only at the early phase of hydrolysis where accumulation of cellobiose and oligomers is significant. Addition of β-glucosidase increased the xylan digestibility of alkaline treated samples due to the β-xylosidase activity present in Novozyme-188.
authors.affiliation: Department of Chemical Engineering, Auburn University, 212 Ross Hall, Auburn, AL 36849, USA.
authors.forename: Venkata Ramesh
authors.initials: VR
authors.lastname: Pallapolu
authors.forename: Y Y
authors.initials: YY
authors.lastname: Lee
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Garlock
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Balan
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Dale
authors.forename: Youngmi
authors.initials: Y
authors.lastname: Kim
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Mosier
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ladisch
authors.forename: Matthew
authors.initials: M
authors.lastname: Falls
authors.forename: Mark T
authors.initials: MT
authors.lastname: Holtzapple
authors.forename: Rocio
authors.initials: R
authors.lastname: Sierra-Ramirez
authors.forename: Jian
authors.initials: J
authors.lastname: Shi
authors.forename: Mirvat A
authors.initials: MA
authors.lastname: Ebrik
authors.forename: Tim
authors.initials: T
authors.lastname: Redmond
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wyman
authors.forename: Bryon S
authors.initials: BS
authors.lastname: Donohoe
authors.forename: Todd B
authors.initials: TB
authors.lastname: Vinzant
authors.forename: Richard T
authors.initials: RT
authors.lastname: Elander
authors.forename: Bonnie
authors.initials: B
authors.lastname: Hames
authors.forename: Steve
authors.initials: S
authors.lastname: Thomas
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Warner
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002475:Cellobiose / Q000378:metabolism; D005936:Glucans / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D008897:Panicum / Q000187:drug effects / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D005936:Glucans; D002475:Cellobiose; D001617:beta-Glucosidase; D005947:Glucose