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Purification and characterization of an alkaliphilic endo‐xylanase from Streptomyces althioticus LMZM and utilization in the pulp paper industry
Author(s) -
Luo Ling,
Cai Jun,
Wang Changgao,
Lin Jianguo,
Du Xin,
Zhou Ansheng,
Xiang Mengxiong
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4690
Subject(s) - xylanase , sephadex , chemistry , chromatography , size exclusion chromatography , corncob , xylose , enzyme assay , enzyme , pulp (tooth) , column chromatography , kraft process , biochemistry , fermentation , kraft paper , organic chemistry , pulp and paper industry , medicine , raw material , pathology , engineering
BACKGROUND Xylanase is the key enzyme involved in the conversion of lignocelluloses. RESULTS An extracellular xylanase from Streptomyces althioticus LMZM submerged culture medium using corncob was purified and characterized. The enzyme was purified 12.65‐fold through ammonium sulphate precipitation, Sephadex G‐25, DEAE cellulose chromatography, followed by gel filtration through a Sephadex G–100 column. The molecular mass of purified xylanase was about 31.75 kDa . The enzyme was an endo‐xylanase, as it degraded xylan to xylooligosaccharide with non‐xylose after 24 h. The purified enzyme showed optimum activity at 60 °C and at pH 8.0 but remained active over a wide range of pH (6.0–11.0) and temperature (40–80 °C). The enzyme retained 98.72% and 69.50% residual enzyme activity at pH 8.0 and at 60 °C after 1 h. The K m and V max values were found to be 43.03 mg mL −1 and 312.5 µmol (min mg −1 ), respectively. The enzyme was remarkably activated by cysteine and Cu 2+ , and its activity was strongly inhibited by Hg 2+ . The brightness of kraft pulp was improved by this xylanase. CONCLUSION Since the enzyme was active over a wide range of pH , and remained active at high temperature, it could find potential uses in biobleaching processes in pulp paper industries and in the production of xylooligosacaharides. © 2015 Society of Chemical Industry