title: Raman spectroscopy measurements of glucose and xylose in hydrolysate: role of corn stover pretreatment and enzyme composition.
abstract: The effect of corn stover pretreatment on glucose quantitation in hydrolysate using Raman spectroscopy is evaluated. Dilute sulfuric-acid pretreatment results in a 20 mg mL(-1) glucose limit of detection in hydrolysate. Soaking in aqueous ammonia pretreatment produces a 4 mg mL(-1) limit of detection. Water, ethanol or hexane extraction of corn stover reduces the spectral background that limits glucose detection in dilute acid hydrolysate. Additionally, a Raman spectroscopy multi-peak fitting method is presented to simultaneously measure glucose and xylose concentration in hydrolysate. This method yields a 6.1% average relative standard error at total saccharide concentrations above 45 mg mL(-1). When only cellulase is present, glucose and xylose yield were measured by Raman spectroscopy to be 32 ± 4 and 7.0 ± 0.8 mg mL(-1), respectively. When both cellulase and hemicellulase were present, xylose yield increased to 18.0 ± 0.5 mg mL(-1). Enzymatic or colorimetric assays confirmed the validity of the Raman spectroscopy results.
authors.affiliation: Ames Laboratory, US Department of Energy, Ames, IA 50011-3111, USA.
authors.forename: Chien-Ju
authors.initials: CJ
authors.lastname: Shih
authors.forename: Jason S
authors.initials: JS
authors.lastname: Lupoi
authors.forename: Emily A
authors.initials: EA
authors.lastname: Smith
mesh_terms: D005947:Glucose / Q000032:analysis*; D006868:Hydrolysis; D057230:Limit of Detection; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014994:Xylose / Q000032:analysis*; D003313:Zea mays
chemical_list: D014994:Xylose; D005947:Glucose