Characterization and detoxification of enzyme hydrolysates derived from dilute ammonia pretreated sorghum bagasse
Tuesday, April 29, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Patrisha J. Pham-Bugayong, Audubon Sugar Institute, Louisiana State University Agricultural Center, St. Gabriel, LA and Giovanna Aita, Audubon Sugar Institute, Louisiana State University, St. Gabriel, LA
Lignocellulosic enzyme hydrolysate detoxification can be challenging because a balance between efficient detoxification strategies while avoiding sugar losses has to be met. In this study, milled Sorghum (Sorghum bicolor) bagasse was pretreated with ammonia (28% NH4OH solution), and water at a ratio of 1:0.5:8 at 160oC and 140-160 psi for 1h in a 300-mL pressure reactor. The pretreated sorghum was enzymatically hydrolyzed with different combinations of Spezyme® CP, a cellulase and Novozyme 188, a β-glucosidase. Samples were collected at various time intervals (0-72h). Enzyme loading was based on the glucan content and mass of dry biomass (sorghum bagasse) added (g glucan/g dry biomass). A 5% biomass loading was used. The resulting enzymatic hydrolysate liquor (EHLx) was analyzed for by- and degradation products. Organic acids, furaldehydes and phenolic acids were qualitatively and quantitatively detected through High Performance Liquid Chromatography (HPLC) - Diode Array Detector (DAD) method, developed for simultaneous and direct detection of EHLx components. Monomeric and oligomeric sugars in the EHLx were identified and quantified through an established HPLC-Refractive Index Detector (RID) method. Various detoxification strategies were evaluated.