Characterization of a Recombinant Thermostable Xylanase from Hot Spring Thermophilic Geobacillus sp. TC-W7

• Published in: Journal of microbiology and biotechnology Vol. 22; no. 10; pp. 1388 - 1394
• Main Author: Liu, Bin
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society for Applied Microbiology 01.10.2012; 한국미생물·생명공학회
• Subjects: Amino Acid Sequence; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Bacterial Proteins - metabolism; Biological and medical sciences; Biotechnology; Chromatography, Affinity - methods; Cloning, Molecular; Edetic Acid - metabolism; Endo-1,4-beta Xylanases - genetics; Endo-1,4-beta Xylanases - isolation & purification; Endo-1,4-beta Xylanases - metabolism; Enzyme Activation; Enzyme Assays; Enzyme Inhibitors - metabolism; Enzyme Stability; Ferric Compounds - metabolism; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genes, rRNA; Geobacillus - enzymology; Geobacillus - genetics; Geobacillus - isolation & purification; Hot Springs - microbiology; Hot Temperature; Hydrogen-Ion Concentration; Metals, Alkali - metabolism; Metals, Heavy - metabolism; Molecular Sequence Data; Octoxynol - metabolism; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 16S - metabolism; Xylans - metabolism; 생물학; TC-W7; stable pH; Enzyme; Thermophily; recombinant expression; Endo-1,4-β-xylanase; Thermal stability; Glycosylases; Characterization; Glycosidases; Geobacillus sp; pH; Hydrolases; Hot source; Xylan endo-1,3-β-xylosidase; Thermostable xylanase
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1203.03045

A xylanase-producing thermophilic strain, Geobacillus sp. TC-W7, was isolated from a hot spring in Yongtai (Fuzhou, China). Subsequently, the xylanase gene that encoded 407 amino acids was cloned and expressed. The recombinant xylanase was purified by GST affinity chromatography and exhibited maximum activity at 75 degrees C and a pH of 8.2. The enzyme was active up to 95 degrees C and showed activity over a wide pH range of 5.2 to 10.2. Additionally, the recombinant xylanase showed high thermostability and pH stability. More than 85% of the enzyme's activity was retained after incubation at 70 degrees C for 90 min at a pH of 8.2. The activity of the recombinant xylanase was enhanced by treatment with 10 mM enzyme inhibitors (DDT, Tween-20, 2-Me, or TritonX-100) and was inhibited by EDTA or PMSF. Its functionality was stable in the presence of Li+, Na+, and K+, but inhibited by Hg2+, Ni2+, Co2+, Cu2+, Zn2+, Pb2+, Fe3+, and Al3+. The functionality of the crude xylanase had similar properties to the recombinant xylanase except for when it was treated with Al2+ or Fe2+. The enzyme might be a promising candidate for various industrial applications such as the biofuel, food, and paper and pulp industries.