Novel Cold‐adaptive Penicillium Strain FS010 Secreting Thermo‐labile Xylanase Isolated from Yellow Sea

• Published in: Acta biochimica et biophysica Sinica Vol. 38; no. 2; pp. 142 - 149
• Main Authors: HOU, Yun‐Hua, WANG, Tian‐Hong, LONG, Hao, ZHU, Hui‐Yuan
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Asia 01-02-2006
• Subjects: Adaptation, Physiological; Base Sequence; Cloning, Molecular; Cold Temperature; cold‐active xylanase; Electrophoresis, Polyacrylamide Gel; Endo-1,4-beta Xylanases - metabolism; Enzyme Stability; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; gene expression; Gene Expression Regulation, Fungal; Genetic Vectors; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Hydrogen-Ion Concentration; marine fungus; Oceans and Seas; Penicillium; Penicillium - enzymology; Penicillium - growth & development; Penicillium chrysogenum; Penicillium chrysogenum - enzymology; Penicillium chrysogenum - growth & development; Recombinant Fusion Proteins - genetics; Temperature; Time Factors
• ISSN: 1672-9145; 1745-7270
• DOI: 10.1111/j.1745-7270.2006.00135.x

A novel cold‐adaptive xylanolytic Penicillium strain FS010 was isolated from Yellow Sea sediments. The marine fungus grew well from 4 to 20 °C; a lower (0 °C) or higher (37 °C) temperature limits its growth. The strain was identified as Penicillium chrysogenum. Compared with mesophilic P. chrysogenum, the cold‐adaptive fungus secreted the cold‐active xylanase (XYL) showing high hydrolytic activities at low temperature (2–15 °C) and high sensitivity to high temperature (>50 °C). The XYL gene was isolated from the cold‐adaptive P. chrysogenum FS010 and designated as xyl. The deduced amino acid sequence of the protein encoded by xyl showed high homology with the sequence of glycoside hydrolase family 10. The gene was subcloned into an expression vector pGEX‐4T‐1 and the encoded protein was over expressed as a fusion protein with glutathione‐S‐transferase in Escherichia coli BL21. The expression product was purified and subjected to enzymatic characterization. The optimal temperature and pH for recombinant XYL was 25 °C and 5.5, respectively. Recombinant XYL showed nearly 80% of its maximal activity at 4 °C and was active in the pH range 3.0–9.5.
Edited by
 Ming‐Hua XU