A new xylanase from Streptomyces megasporus DSM 41476 with high yield of xylobiose.
A new xylanase gene, xynBM4, was cloned from Streptomyces megasporus DSM 41476 and expressed in Pichia pastoris. The full-length gene consists of 1,443 bp and encodes 480 amino acids including a putative 49-residue signal peptide. The deduced amino acid sequence of xynBM4 shows the highest identity of 66.3% to the xylanase Xys1L from Streptomyces halstedii JM8. The purified recombinant XYNBM4 had a high specific activity of 350.7 U mg(-1) towards soluble wheat arabinoxylan, exhibited optimal activity at pH 6.0 and 57°C, showed broad pH adaptability (>75% of the maximum activity at pH 2.5-9.0), was resistant to neutral proteases and most chemicals, and produced simple products. The hydrolysis products of birchwood xylan and corncob xylan were predominantly xylobiose (76.9 and 90.8%, respectively) and no xylose. These characteristics suggest that XYNBM4 has potential in various applications, especially in the food industry.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing, 100081, People's Republic of China.
Pengjun
P
Shi
Zhenhua
Z
Qiu
Yingguo
Y
Bai
Tiezheng
T
Yuan
Huoqing
H
Huang
Xia
X
Pan
Peilong
P
Yang
Wei
W
Zhang
Bin
B
Yao
D000595:Amino Acid Sequence; D004187:Disaccharides / Q000096:biosynthesis*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D013302:Streptomyces / Q000201:enzymology* / Q000378:metabolism*; D013379:Substrate Specificity
D004187:Disaccharides; D043364:Endo-1,4-beta Xylanases; C004173:xylobiose