African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5241

Full Length Research Paper

Expression and characterization of recombinant cellulases from an isolated Klebsiella

Qian Li
  • Qian Li
  • State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
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Xiao Hong
  • Xiao Hong
  • Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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Xiwen Chen*
  • Xiwen Chen*
  • Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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Defu Chen*
  • Defu Chen*
  • 1. State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; 2. Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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  •  Received: 08 August 2015
  •  Accepted: 31 August 2015
  •  Published: 23 September 2015

Abstract

Seven bacteria strains that have a comparable or higher cellulose degrading capability than Cellulomonas fimi were screened out and phylogenetically analyzed. Genes encoding 1,4-endoglucosidase (celJV) and glucoside hydrolase family 8 (celG) were cloned from Klebsiella sp. strain IV-3, and then inserted separately or simultaneously into pET-22b(+), pETDuet-1 (pDin) or pDout that combined pETDuet-1 with the pelB leader. pETDuet-1 expressed these cellulose genes as soluble protein, while other vectors mainly as inclusion bodies. The recombinant enzyme(s) from pDin-JV-G and pDin-JV had the highest degrading capability to CMC-Na, with the degrading zone diameter corresponding to 2.6- and 1.9-fold of Klebsiella sp. strain IV-3, respectively. They also showed the highest degrading capability to filter paper, which corresponded well with the highest specific activity. Even though pDin-JV-G had lower expression efficiency, it still had higher degrading capability than pDin-JV, indicating that enzymatic synergism is helpful for cellulose degradation.

Key words: Cellulose, cellulase, 1,4-endoglucosidase, glucoside hydrolase family 8, Klebsiella.

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This article is published under the terms of the Creative Commons Attribution License 4.0

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