Purification and Characterization of a recombinant β-Xylosidase from Bacillus licheniformis ATCC 14580 into E. coli Bl21.

Present research work is aimed to purify and characterize a recombinant β-xylosidase enzyme which was previously cloned from Bacillus licheniformis ATCC 14580 in to Escherichia coli BL21. Purification of recombinant enzyme was carried out by using ammonium sulphate precipitation method followed by single step immobilized metal ion affinity chromatography. Specific activity of purified recombinant β-xylosidase enzyme was 20.78 Umg-1 with 2.58 purification fold and 33.75% recovery. SDS-PAGE was used to determine the molecular weight of recombinant purified β-xylosidase and it was recorded as 52 kDa. Purified enzyme showed stability upto 90°C within a pH range of 3-8 with and optimal temperature and pH, 55ºC and 7.0, respectively. The enzyme activity was not considerably affected in the presence of EDTA. An increase in the enzyme activity was found in the manifestation of Mg+2. Enzyme activity was also increased by 6%, 18% and 22% in the presence of 1% Tween 80, β-mercaptoethanol and DTT, respectively. Higher concentrations (10 - 40%) of organic solvents did not show any effect upon activity of enzyme. All these characteristics of the recombinant enzyme endorsed it as a potential candidate for biofuel industry.