title: Modeling of pretreatment condition of extrusion-pretreated prairie cordgrass and corn stover with poly (oxyethylen)20 sorbitan monolaurate.
abstract: Extrusion processing has shown potential to be used as a pretreatment method for second-generation bioethanol production. Furthermore, surfactants have been shown to reduce enzyme deactivation and increase the efficiency of hydrolysis. Therefore, a sequential pretreatment technique was developed for corn stover (CS) and prairie cordgrass (PCG) in which a single screw extruder was used for the first pretreatment according to a previously optimized condition using 70-180 °C for feed, barrel, and die zones with 65-155 rpm screw speed. The second pretreatment was optimized in this study at 45-55 °C, 1-4 h, 0.15-0.6 g Tween 20/g glucan according to response surface methodology. Optimization of surfactant pretreatment facilitated the estimation of interaction and higher-order effects for major factors involved in surfactant treatment (temperature, time, surfactant loading). Using 8.6 FPU/g glucan cellulase, the optimum conditions found by fitting appropriate quadratic models to the data increased glucose and xylose yield by 27.5 and 33% for CS and by 21.5 and 27% for PCG, respectively. Tween 20 concentrations and pretreatment temperature were the most significant factors affecting sugar yield (p value <0.05). Studies of SDS concentration at and beyond critical micelle concentration (5.2-100 mM) demonstrated a decrease in sugar yield compared to control.
authors.affiliation: Department of Agricultural and Biosystems Engineering, South Dakota State University, Brookings, SD 57007, USA. Anahita.Eckard@sdstate.edu
authors.forename: Anahita Dehkhoda
authors.initials: AD
authors.lastname: Eckard
authors.forename: Kasiviswanathan
authors.initials: K
authors.lastname: Muthukumarappan
authors.forename: William
authors.initials: W
authors.lastname: Gibbons
mesh_terms: D001709:Biotechnology / Q000379:methods*; D006601:Hexoses / Q000737:chemistry; D006868:Hydrolysis; D008956:Models, Chemical; D006109:Poaceae / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D013696:Temperature; D003313:Zea mays / Q000737:chemistry*
chemical_list: D006601:Hexoses; D011092:Polyethylene Glycols; C014822:sorbitan monolaurate