Submitted to: Extremophiles
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2005
Publication Date: 3/11/2006
Citation: Lee, C.C., Accinelli, R., Wagschal, K.C., Robertson, G.H., Wong, D. 2006. Cloning and characterization of a cold active xylanase enzyme. Extremophiles. 10:295-300. Interpretive Summary: Xylanases are enzymes that are widely used in industrial processes that range from biofuel production to food preparation. We have isolated and characterized a xylanase enzyme that is active at cold temperatures. This discovery could lead to decreased energy costs as the reactions can be conducted at lower temperatures. In addition, the enzyme may be useful to process products that are sensitive to high temperatures, such as foodstuffs.
Technical Abstract: There is great interest in xylanases due to the wide variety of industrial applications for these enzymes. We cloned a xylanase gene (xyn8) from an environmental genomic DNA library. The encoded enzyme was predicted to be 399 amino acids with a molecular weight of 45.9 kD. Sequence analysis of the putative catalytic domain determined that the enzyme should be categorized as a glycosyl hydrolase family 8 member. The purified enzyme was thermolabile, had an activity temperature optimum of 20oC on native xylan substrate, and retained significant activity at lower temperatures. At 4oC, the apparent Km was 3.7 mg/ml, and the apparent kcat was 123 sec-1.