TITLE:
Purification and Characterization of Alkaline Xylanase Secreted from Paenibacillus macquariensis
AUTHORS:
Meeta Sharma, Saurabh Mehta, Anil Kumar
KEYWORDS:
Xylanase; Paenibacillus macquariensis; Purification; Michaelis Constant; Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis
JOURNAL NAME:
Advances in Microbiology,
Vol.3 No.1,
March
27,
2013
ABSTRACT: An alkaline xylanase secreted by Paenibacillus macquariensis RC 1819 has been purified using ammonium sulfate fractionation, ion exchange chromatography using DEAE-cellulose and gel filtration chromatography over Sephadex G-200 and Sephadex G-100. The purified enzyme had the specific activity, 25.2 units/mg protein with birchwood xylan as a substrate. The purified enzyme showed a single protein band over sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of the enzyme has been found to be 31,000 ± 2000 as determined by using Sephadex G-200 gel filtration chromatography. The subunit molecular weight has also been found to be ~31,000 as determined using SDS-PAGE indicating monomeric enzyme. The enzyme showed optimum activity at pH 8.6 and temperature, 50°C. The Michaelis constant (Km) of the enzyme for birchwood xylan was 2.2 mg/ml as determined using velocity saturation plot. The metal ions viz. Co+2 and Mn+2 stimulated xylanase enzyme activity whereas Hg+2 inhibited the enzyme activity.