title: Influence of physico-chemical changes on enzymatic digestibility of ionic liquid and AFEX pretreated corn stover.
abstract: Ionic liquid (IL) and ammonia fiber expansion (AFEX) pretreatments were studied to develop the first direct side-by-side comparative assessment on their respective impacts on biomass structure, composition, process mass balance, and enzymatic saccharification efficiency. AFEX pretreatment completely preserves plant carbohydrates, whereas IL pretreatment extracts 76% of hemicellulose. In contrast to AFEX, the native crystal structure of the recovered corn stover from IL pretreatment was significantly disrupted. For both techniques, more than 70% of the theoretical sugar yield was attained after 48 h of hydrolysis using commercial enzyme cocktails. IL pretreatment requires less enzyme loading and a shorter hydrolysis time to reach 90% yields. Hemicellulase addition led to significant improvements in the yields of glucose and xylose for AFEX pretreated corn stover, but not for IL pretreated stover. These results provide new insights into the mechanisms of IL and AFEX pretreatment, as well as the advantages and disadvantages of each.
authors.affiliation: Deconstruction Division, Joint BioEnergy Institute, Emeryville, CA, USA.
authors.forename: Chenlin
authors.initials: C
authors.lastname: Li
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Balan
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kent
authors.forename: Markus
authors.initials: M
authors.lastname: Ong
authors.forename: Shishir P S
authors.initials: SP
authors.lastname: Chundawat
authors.forename: Leonardo daCosta
authors.initials: Ld
authors.lastname: Sousa
authors.forename: Yuri B
authors.initials: YB
authors.lastname: Melnichenko
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Dale
authors.forename: Blake A
authors.initials: BA
authors.lastname: Simmons
authors.forename: Seema
authors.initials: S
authors.lastname: Singh
mesh_terms: D000641:Ammonia / Q000494:pharmacology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry; D002482:Cellulose / Q000032:analysis; D055598:Chemical Phenomena / Q000187:drug effects*; D003460:Crystallization; D004798:Enzymes / Q000378:metabolism*; D006868:Hydrolysis / Q000187:drug effects; D052578:Ionic Liquids / Q000494:pharmacology*; D008031:Lignin / Q000032:analysis; D033363:Neutron Diffraction; D016062:Porosity / Q000187:drug effects; D053838:Scattering, Small Angle; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties / Q000187:drug effects; D014866:Waste Products / Q000032:analysis*; D003313:Zea mays / Q000187:drug effects*
chemical_list: D002241:Carbohydrates; D004798:Enzymes; D052578:Ionic Liquids; D014866:Waste Products; D000641:Ammonia; D002482:Cellulose; D008031:Lignin