title: Batch and multi-step fed-batch enzymatic saccharification of Formiline-pretreated sugarcane bagasse at high solid loadings for high sugar and ethanol titers.
abstract: Formiline pretreatment pertains to a biomass fractionation process. In the present work, Formiline-pretreated sugarcane bagasse was hydrolyzed with cellulases by batch and multi-step fed-batch processes at 20% solid loading. For wet pulp, after 144 h incubation with cellulase loading of 10 FPU/g dry solid, fed-batch process obtained ~150 g/L glucose and ~80% glucan conversion, while batch process obtained ~130 g/L glucose with corresponding ~70% glucan conversion. Solid loading could be further increased to 30% for the acetone-dried pulp. By fed-batch hydrolysis of the dried pulp in pH 4.8 buffer solution, glucose concentration could be 247.3±1.6 g/L with corresponding 86.1±0.6% glucan conversion. The enzymatic hydrolyzates could be well converted to ethanol by a subsequent fermentation using Saccharomices cerevisiae with ethanol titer of 60-70 g/L. Batch and fed-batch SSF indicated that Formiline-pretreated substrate showed excellent fermentability. The final ethanol concentration was 80 g/L with corresponding 82.7% of theoretical yield.
authors.affiliation: Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. zhaoxb@mail.tsinghua.edu.cn
authors.forename: Xuebing
authors.initials: X
authors.lastname: Zhao
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Dehua
authors.initials: D
authors.lastname: Liu
mesh_terms: D000096:Acetone / Q000494:pharmacology; D061249:Batch Cell Culture Techniques / Q000379:methods*; D050260:Carbohydrate Metabolism / Q000187:drug effects*; D002241:Carbohydrates / Q000096:biosynthesis*; D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005561:Formates / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D031786:Saccharum / Q000187:drug effects / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D005561:Formates; C030544:formic acid; D000096:Acetone; D000431:Ethanol; D002482:Cellulose; C027433:bagasse; D002480:Cellulase; D005947:Glucose