科研之友
微信
新浪微博
Facebook
分享链接
摘要
Paenibacillus xylanilyticus KJ-03 was isolated from soil samples obtained from a field with Amorphophallus konjac plants. A gene encoding xylanase was isolated from KJ-03 and cloned using a fosmid library. The xynA gene encodes xylanase; it consists of 1,035 bp and encodes 345 amino acids. The amino acid sequence deduced from the xylanilyticus KJ-03 xylanase showed 81% and 69% identities with those deduced from the P polymyxa E681 and Paenibacillus sp. HPL-001 xylanases, respectively. The xynA gene comprises a single domain, consisting of a catalytic domain of the glycosyl hydrolase (GH) 10 family. The xynA gene was expressed in Escherichia colt BL21 (trxB), and the recombinant xylanase was purified by Ni-affinity chromatography. The purified xylanase showed optimum activity with birchwood xylan as a substrate at 40 degrees C and pH 7.4. Treatment with Mg2+ and Li+ showed a slight decrease in XynA activity; however, treatment with 5 mM Cu2+ completely inhibited its activity. The results of the thin layer chromatography analysis indicated that the major hydrolysis product was xylobiose and small amounts of xylose and xylotriose. XynA showed increased activity with oat spelt xylan and birchwood xylan, but showed only slight activity with locust bean gum.
- 出版日期2013-3
