title: Pretreatment of corn stover by soaking in aqueous ammonia at moderate temperatures.
abstract: Soaking in aqueous ammonia at moderate temperatures was investigated as a method of pretreatment for enzymatic hydrolysis as well as simultaneous saccharification and cofermentation (SSCF) of corn stover. The method involves batch treatment of the feedstock with aqueous ammonia (15-30 wt%) at 40-90 degrees C for 6-24 h. The optimum treatment conditions were found to be 15 wt% of NH(3), 60 degrees C, 1:6 of solid-to-liquid ratio, and 12 h of treatment time. The treated corn stover retained 100% glucan and 85% of xylan, but removed 62% of lignin. The enzymatic digestibility of the glucan content increased from 17 to 85% with 15 FPU/g-glucan enzyme loading, whereas the digestibility of the xylan content increased to 78%. The treated corn stover was also subjected to SSCF test using Spezyme-CP and recombinant Escherichia coli (KO11). The SSCF of the soaking in aqueous ammonia treated corn stover resulted in an ethanol concentration of 19.2 g/L from 3% (w/v) glucan loading, which corresponds to 77% of the maximum theoretical yield based on glucan and xylan.
authors.affiliation: US Department of Agriculture, ERRC, ARS, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.forename: Y Y
authors.initials: YY
authors.lastname: Lee
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry* / Q000378:metabolism*; D007220:Industrial Waste / Q000517:prevention & control; D035261:Plant Components, Aerial / Q000737:chemistry / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology*
chemical_list: D007220:Industrial Waste; D014867:Water; D000431:Ethanol; D000641:Ammonia