Purification and characterization of an alkaliphilic endo‐xylanase from Streptomyces althioticusLMZM and utilization in the pulp paper industry

Abstract

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 mol (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.

A detailed overview of xylanases: an emerging biomolecule for current and future prospective

“…Several alkali stable xylanases have been isolated from firmicutes such as B. pumilus (Thomas et al 2014), B. halodurans TSEV1 (Kumar and Satyanarayana 2014) and Geobacillus thermoleovorans (Verma and Satyanarayana 2012b) and actinomycetes such as Actinomadura sp. Cpt20 (Taibi et al 2012) and Streptomyces althioticus LMZM (Luo et al 2016).…”

Bacterial xylanases: biology to biotechnology

“…abd Actinomadura sp. (Luo et al 2015 ; Taibi et al 2012 ) have been reported as potential source of alkali stable xylanases. Xylanases with such unique features have found diverse application in various industries.…”

Production and Characterization of Partially Purified Thermostable Endoxylanase and Endoglucanase from Novel Actinomadura geliboluensis and the Biotechnological Applications in the Saccharification of Lignocellulosic Biomass

“…The Vmax and Km values of endoxylanase were 292.2 (± 5.72) U/min and 3.87 (± 0.16) mg/mL, and the Vmax and Km values of endoglucanase were 18.03 (± 0.35) U/min and 3.57 (± 0.22) mg/mL, respectively. The Km value of endoxylanase from A. geliboluensis was lower than endoxylanase obtained from Streptomyces cyaneus SN32 (11.1 mg/mL) (Ninawe et al 2008) and Streptomyces althioticus LMZM (43.03 mg/mL) (Luo et al 2016). The Km value of endoglucanase has been reported in the range of 3.0 to 4.0 mg/mL for CMC (Wang et al 2009;Rastogi et al 2010).…”

“…RCK-2010 (Kumar et al 2012), Streptomyces sp. SWU10 (Deesukon et al 2011), Streptomyces matensis (Yan et al 2009), Streptomyces cyaneus SN32 (Ninawe et al 2008), Streptomyces actuosus A-151 (Wang et al 2003), and Streptomyces althioticus LMZM (Luo et al 2016) have the same optimal temperature. However, the relative activity of xylanases from these microorganisms decreased rapidly when the temperature was increased from 60 °C to 90 °C.…”