首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Purification and some properties of an alkaline xylanase from alkaliphilic Bacillus sp. strain 41M-1.
Authors:S Nakamura  K Wakabayashi  R Nakai  R Aono  and K Horikoshi
Abstract:An alkaliphilic Bacillus sp. strain, 41M-1, isolated from soil produced multiple xylanases extracellularly. One of these xylanases was purified to homogeneity by ammonium sulfate fractionation and anion-exchange chromatography. The moleculr mass of this enzyme (xylanase J) was 36 kDa, and the isoelectric point was pH 5.3. Xylanase J was most active at pH 9.0. The optimum temperature for the activity at pH 9.0 was around 50 degrees C. The enzyme was stable up to 55 degrees C at pH 9.0 for 30 min. Xylanase J was completely inhibited by the Hg2+ion and N-bromosuccinimide. The predominant products of xylan hydrolysate were xylobiose, xylotriose, and higher oligosaccharides, indicating that the enzyme was an endoxylanase. The apparent Km and Vmax values on xylan were 3.3 mg/ml and 1,100 micromol-1 mg-1, respectively. Xylanase J showed high sequence homology with the xylanases from Bacillus pumilus and Clostridium acetobutylicum in the N-terminal region. Xylanase J acted on neither crystalline cellulose nor carboxymethyl cellulose, indicating a possible application of the enzyme in biobleaching processes.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号