Comparative hydrolysis effect of industrial xylanase purified from Bacillus stearothermophilus (ATCC 12980) on two kinds of xylan

Xylan the major portion of the hemicellulose of plant cell wall is a heterogeneous polysaccharide. Xylanases (EC:3.2.1.8) are enzymes obtained from different species of microorganisms that degrade the xylosidic linkages of xylan’s backbone producing xylose plus other monoresidues. In this study xylanase of Bacillus stearothermophilus (ATCC 12980) was purified from culture broth supernatant using ammonium sulfate precipitation, gel filtration on sephadex G-100 followed by ion exchange chromatography on DEAE-cellulose and hydrolysis effect of purified xylanse on two kinds of xylan (birch wood and oat spelts) was studied. In DEAE-cellulose column chromatography, three protein peaks F-1a, F-1b and F-1c were appeared. Among these peaks, only F-1b showed xylanase activity and the degree of purification attained 63.09 fold. The specific activity and purification fold of the purified xylanase was 87.7 U/mg of protein and 17.45, respectively. Hydrolysis of birch wood and oat spelts by purified xylanase was 100% and 56.8% in 24 h, respectively. In conclusion, these data suggested that purified xylanase can be suitable for industrial applications in that birch wood was used.