Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Jae-Won Lee; Rita C.L.B. Rodrigues; Hyun Joo Kim; In-Gyu Choi; Thomas W. Jeffries
    Date: 2010
    Source: Bioresource technology. Vol. 101, no. 12 (June 2010): p. 4379-4385.
    Publication Series: Miscellaneous Publication
    PDF: Download Publication  (378.93 KB)


    High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 23 full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment condition to release sugar from the cob of Zea mays L. ssp. and for Pichia stipitis CBS 6054. To ferment the residual cellulosic sugars to ethanol following enzymatic hydrolysis, highest saccharification and fermentation yields were obtained following pretreatment at 180 °C for 50 min with 0.024 g oxalic acid/g substrate. Under these conditions, only 7.5% hemicellulose remained in the pretreated substrate. The rate of cellulose degradation was significantly less than that of hemicellulose and its hydrolysis was not as extensive. Subsequent enzymatic saccharification of the residual cellulose was strongly affected by the pretreatment condition with cellulose hydrolysis ranging between 26.0% and 76.2%. The residual xylan/lignin ratio ranged from 0.31 to 1.85 depending on the pretreatment condition. Fermentable sugar and ethanol were maximal at the lowest ratio of xylan/lignin and at high glucan contents. The model predicts optimal condition of oxalic acid pretreatment at 168 °C, 74 min and 0.027 g/g of oxalic acid. From these findings, we surmised that low residual xylan was in obtaining maximal glucose yields from saccharification.

    Publication Notes

    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Lee, Jae-Won; Rodrigues, Rita C.L.B.; Kim, Hyun Joo; Choi, In-Gyu; Jeffries, Thomas W. 2010. The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation. Bioresource technology. Vol. 101, no. 12 (June 2010): p. 4379-4385.


    Google Scholar


    Oxalic acid, alcohol, fermentation, corncobs, corn, residues, pretreatment, biomass, biomass energy, fungi, biotechnology, yeast fungi, enzymes, cellulase, hemicellulose, industrial applications, factorial experiment design, temperature, Pichia stipitis, hydrolysis, lignin, biodegradation, glucose, ethanol, saccharification, response surface methodology, biomass fuel, biorefining, bioconversion, corn as fuel, xylan, decay fungi

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page