title: Comparative data on effects of leading pretreatments and enzyme loadings and formulations on sugar yields from different switchgrass sources.
abstract: Dilute sulfuric acid (DA), sulfur dioxide (SO(2)), liquid hot water (LHW), soaking in aqueous ammonia (SAA), ammonia fiber expansion (AFEX), and lime pretreatments were applied to Alamo, Dacotah, and Shawnee switchgrass. Application of the same analytical methods and material balance approaches facilitated meaningful comparisons of glucose and xylose yields from combined pretreatment and enzymatic hydrolysis. Use of a common supply of cellulase, beta-glucosidase, and xylanase also eased comparisons. All pretreatments enhanced sugar recovery from pretreatment and subsequent enzymatic hydrolysis substantially compared to untreated switchgrass. Adding beta-glucosidase was effective early in enzymatic hydrolysis while cellobiose levels were high but had limited effect on longer term yields at the enzyme loadings applied. Adding xylanase improved yields most for higher pH pretreatments where more xylan was left in the solids. Harvest time had more impact on performance than switchgrass variety, and microscopy showed changes in different features could impact performance by different pretreatments.
authors.affiliation: Chemical and Environmental Engineering Department, University of California, Riverside, CA 92506, USA. charles.wyman@ucr.edu
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wyman
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Balan
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Dale
authors.forename: Richard T
authors.initials: RT
authors.lastname: Elander
authors.forename: Matthew
authors.initials: M
authors.lastname: Falls
authors.forename: Bonnie
authors.initials: B
authors.lastname: Hames
authors.forename: Mark T
authors.initials: MT
authors.lastname: Holtzapple
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ladisch
authors.forename: Y Y
authors.initials: YY
authors.lastname: Lee
authors.forename: Nathan
authors.initials: N
authors.lastname: Mosier
authors.forename: Venkata R
authors.initials: VR
authors.lastname: Pallapolu
authors.forename: Jian
authors.initials: J
authors.lastname: Shi
authors.forename: Steven R
authors.initials: SR
authors.lastname: Thomas
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Warner
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D002480:Cellulase / Q000378:metabolism; D060146:Ecotype; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D005947:Glucose / Q000032:analysis; D006868:Hydrolysis; D008897:Panicum / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D012621:Seasons; D014994:Xylose / Q000032:analysis; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D004798:Enzymes; D000641:Ammonia; D014994:Xylose; D001617:beta-Glucosidase; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases; D005947:Glucose