Applied Biochemistry and Biotechnology

, Volume 154, Issue 1–3, pp 108–122 | Cite as

Assessment of Xylanase Activity in Dry Storage as a Potential Method of Reducing Feedstock Cost

  • William A. SmithEmail author
  • David N. Thompson
  • Vicki S. Thompson
  • Corey W. Radtke
  • Brady Carter


Enzymatic preprocessing of lignocellulosic biomass in dry storage systems has the potential to improve feedstock characteristics and lower ethanol production costs. To assess the potential for endoxylanase activity at low water contents, endoxylanase activity was tested using a refined wheat arabinoxylan substrate and three commercial endoxylanases over the water activity range 0.21–1.0, corresponding to water contents of 5% to >60% (dry basis). Homogeneously mixed dry samples were prepared at a fixed enzyme to substrate ratio and incubated in chambers at a variety of fixed water activities. Replicates were sacrificed periodically, and endoxylanase activity was quantified as an increase in reducing sugar relative to desiccant-stored controls. Endoxylanase activity was observed at water activities over 0.91 in all enzyme preparations in less than 4 days and at a water activity of 0.59 in less than 1 week in two preparations. Endoxylanase activity after storage was confirmed for selected desiccant-stored controls by incubation at 100% relative humidity. Water content to water activity relationships were determined for three lignocellulosic substrates, and results indicate that two endoxylanase preparations retained limited activity as low as 7% to 13% water content (dry basis), which is well within the range of water contents representative of dry biomass storage. Future work will examine the effects of endoxylanase activity toward substrates such as corn stover, wheat straw, and switchgrass in low water content environments.


Endoxylanase Water activity Water content Biomass Lignocellulose Storage Feedstock Preprocessing Stability 



The authors thank Liz Taylor and Karen Delezene-Briggs of the Idaho National Laboratory Biological Systems department for their technical assistance and Robert Cherry of the Idaho National Laboratory Energy Systems and Technology department for his critical review. This work was supported by the United States Department of Energy, Office of the Biomass Program, under DOE-NE Idaho Operations Office Contract DE-AC07-05ID14517.


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Copyright information

© US Government 2008

Authors and Affiliations

  • William A. Smith
    • 1
    Email author
  • David N. Thompson
    • 1
  • Vicki S. Thompson
    • 1
  • Corey W. Radtke
    • 2
  • Brady Carter
    • 3
  1. 1.Biological Systems DepartmentIdaho National LaboratoryIdaho FallsUSA
  2. 2.Biomass Upstream DepartmentShell Global Solutions (US)HoustonUSA
  3. 3.Decagon DevicesPullmanUSA

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