title: Evaluation of steam-treated giant bamboo for production of fermentable sugars.
abstract: Giant bamboo plantations are currently being established in the Southern Africa region and can be considered as potential lignocellulosic feedstock for the production of second generation bioethanol. In this study, giant bamboo internodal material was subjected to sulphur dioxide (SO(2)) impregnated steam pretreatment prior to enzymatic hydrolysis. The effect of temperature, residence time, and acidity on the overall sugar recovery and byproduct formation was studied using response surface response technology according to a central composite experimental design (CCD) at a fixed SO(2) concentration of 2.5% (w/w liquid) after impregnation. The results showed that pretreatment conditions with combined severity factor (CSF) values and enzyme dosages greater than 1.72 and 30 FPU/g water insoluble solid, respectively, were required to obtain an efficient glucan digestibility and a good overall glucose recovery. Up to 81.2% of the sugar in the raw material was recovered for a CSF of 2.25. However, considering overall sugar yield and byproducts concentration, the pretreated material obtained with a CSF of 1.62 can be considered as the most appropriate for SSF experiments using a xylose-utilizing yeast. At these conditions, it could be possible to obtain up to 247 L of ethanol per dry ton of giant bamboo considering hexose and pentose sugars fermentation. This amount could be increased up to 292 L of ethanol per dry ton of giant bamboo with the maximum sugar yield obtained (CSF = 2.25) if the microorganism possesses robust fermentative characteristics as well as a high resistance to pretreatment by-products.
authors: Dept. of Process Engineering, Stellenbosch University, Private Bag X1 Stellenbosch 7602 South Africa. garcia@sun.ac.za
authors: María
authors: M
authors: García-Aparicio
authors: Wilson
authors: W
authors: Parawira
authors: Eugéne
authors: E
authors: Van Rensburg
authors: Danie
authors: D
authors: Diedericks
authors: Mats
authors: M
authors: Galbe
authors: Christian
authors: C
authors: Rosslander
authors: Guido
authors: G
authors: Zacchi
authors: Johann
authors: J
authors: Görgens
mesh_terms: D000353:Africa, Southern; D000821:Animal Feed; D031723:Bambusa / Q000382:microbiology*; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000096:biosynthesis*; D000431:Ethanol; D005285:Fermentation; D013227:Steam
chemical_list: D002241:Carbohydrates; D013227:Steam; D000431:Ethanol