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Purification and characterization of a cellulase-free, thermostable xylanase from Streptomyces rameus L2001 and its biobleaching effect on wheat straw pulp

Paper ID Volume ID Publish Year Pages File Format Full-Text
3871 196 2010 8 PDF Available
Title
Purification and characterization of a cellulase-free, thermostable xylanase from Streptomyces rameus L2001 and its biobleaching effect on wheat straw pulp
Abstract

A xylanase purified from Streptomyces rameus L2001 and the biobleaching effect on wheat straw pulp was investigated. The extracellular xylanase was purified 13.3-fold by precipitation with 40–60% (NH4)2SO4, DEAE-52 and CM Sepharose Fast Flow ion exchange chromatography. It appeared as a monomeric protein on SDS-PAGE gel and had a molecular mass of approx. 21.1 kDa, with a specific activity of 3236.6 U/mg. The purified xylanase had an optimum pH of 5.3 and was stable over pH 4.3–6.7. The stable optimal temperature of the enzyme was 70 °C. The xylanase was activated by Co2+ by up to 329% of baseline activity. The xylanase was highly specific towards xylan, but did not exhibit other enzyme activity. Apparent Km values of the xylanase for birchwood and beechwood were 5.8 and 5.3 mg mL−1, respectively. The potential application of the xylanase was further evaluated in wheat straw pulp. The amount of reducing sugars released by the xylanase from wheat straw pulp was significantly greater with increasing time. Enzymatic treatment at a charge of 20 U/g dry pulp for 1 h before hypochlorite (3.8%) treatment revealed an increase in brightness index by 2.8% and increase in residual chlorine by 14.5%.

Keywords
CAPS, (cyclohexylamino)-1-propanesulfonic acid; CHES, 2-(cyclohexylamino)-ethanesulfonic acid; CMC, carboxymethylcellulose; EDTA, ethylenediaminetetraacetic acid; MES, 2-(N-morpholino)-ethane sulfonic acid; MOPS, 3-(N-morpholino)-propanesulfonic acid; pNP
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Purification and characterization of a cellulase-free, thermostable xylanase from Streptomyces rameus L2001 and its biobleaching effect on wheat straw pulp
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 52, Issue 1, 15 October 2010, Pages 71–78
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us