A novel xylanase, XynA4-2, from thermoacidophilic Alicyclobacillus sp A4 with potential applications in the brewing industry

作者：Wang, Jianshe; Bai, Yingguo; Shi, Pengjun; Luo, Huiying; Huang, Huoqing; Yin, Jun; Yao, Bin^*

来源：WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY, 2011, 27(2): 207-213.

DOI：10.1007/s11274-010-0445-0

• Alicyclobacillus sp A4
• Xylanase
• pH stability
• Mash
• Viscosity
• Filtration rate

A xylanase gene, xynA4-2, was obtained from the genome sequence of thermoacidophilic Alicyclobacillus sp. A4 and expressed in Escherichia coli BL21 (DE3). xynA4-2 encodes a mature protein of 411 residues with a calculated molecular weight of 46.8 kDa. Based on the amino acid sequence similarities (highest identity of 61%), the enzyme was confined into glycoside hydrolase family 10. The purified recombinant XynA4-2 exhibited maximum activity at pH 6.2 and 55A degrees C. The enzyme was stable over a broad pH range, retaining more than 90% of the original activity at pH 5.8-12.0, 37A degrees C for 1 h. The substrate specificity of XynA4-2 was relatively narrow, exhibiting 100, 93, and 35% of the relative activity towards birchwood xylan, oat spelt xylan, and wheat arabinoxylan, respectively. Supplementation of XynA4-2 to mash caused the reduction of mash filtration rate (5.6%) and viscosity (4.0%). When combined with the commercial glucanase from Sunson, higher reduction was detected in the filtration rate (12.0%) and viscosity (17.2%). These favorable properties make XynA4-2 a good candidate in the brewing industry.

• 出版日期2011-2
• 单位内蒙古农业大学; 中国农业科学院