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United States Department of Agriculture

Agricultural Research Service

Title: Cloning of Bacillus licheniformis xylanase gene and characterization of recombinant enzyme

Authors
item Lee, Charles
item Kibblewhite, Rena
item Smith, Michael
item Wagschal, Kurt
item Orts, William
item Wong, Dominic

Submitted to: Current Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2008
Publication Date: August 9, 2008
Citation: Lee, C.C., Accinelli, R., Smith, M.R., Wagschal, K.C., Orts, W.J., Wong, D. 2008. Cloning of Bacillus licheniformis xylanase gene and characterization of recombinant enzyme. Current Microbiology. 57:301-305.

Interpretive Summary: Lignocellulosic biomass is considered a prime alternative to fossil fuels as a source for many of our fuel and chemical feedstock needs. After cellulose, hemicellulose comprises the largest fraction of biomass. Improved breakdown of hemicellulose is a key factor in maximizing biomass utilization. Hemicellulose is comprised primarily of xylan, a polymer of xylose residues. We cloned a gene that encode a xylanase enzyme which will degrade xylan. We biochemically characterized the enzyme and demonstrated it's ability to break down xylan under a variety of conditions.

Technical Abstract: Hemicellulose is a major component of lignocellulose biomass. Complete enzymatic degradation of this substrate requires several different activities, including xylanase. We isolated a strain of Bacillus licheniformis from a hot springs environment that exhibited xylanase activity. A gene encoding a xylanase enzyme, Xyn11, was cloned, and recombinant protein was expressed in an Escherichia coli host and biochemically characterized. The optimum activity of the enzyme was at pH 6 and 40-50oC. The enzyme was thermal stable up to 50oC. Against birch wood xylan, the enzyme had apparent Km of 6.7 mg/ml and Vmax of 379 micromol/min/mg.

Last Modified: 12/24/2014
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