Applied Microbiology and Biotechnology

, Volume 97, Issue 11, pp 4887–4896

Autodisplay of nitrilase from Klebsiella pneumoniae and whole-cell degradation of oxynil herbicides and related compounds

  • Christian Detzel
  • Ruth Maas
  • Agne Tubeleviciute
  • Joachim Jose
Biotechnologically relevant enzymes and proteins

DOI: 10.1007/s00253-012-4401-9

Cite this article as:
Detzel, C., Maas, R., Tubeleviciute, A. et al. Appl Microbiol Biotechnol (2013) 97: 4887. doi:10.1007/s00253-012-4401-9

Abstract

Using the Autodisplay system, a recombinant Escherichia coli strain displaying the dimeric nitrilase from Klebsiella pneumoniae subsp. ozaenae (NitKp) on the cell surface was constructed. Localization of the nitrilase in the cell envelope of E. coli was monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis and surface exposure was verified by its accessibility to externally added protease. The whole-cell biocatalyst obtained converted the substrates analyzed in the following order: chloroxynil > bromoxynil > ioxynil > 3-bromo-4-hydroxybenzonitrile (1.67, 0.89, 0.13, and 0.09 mM product formation within 72 h, respectively), indicating the same substrate specificity for the displayed enzyme as for the free enzyme. The whole-cell biocatalyst was also able to convert 3-fluoro-4-hydroxybenzonitrile and 3,5-dimethyl-4-hydroxybenzonitrile to the corresponding carboxylic acids. In contrast, it was not possible to detect any enzyme activity when 4-methoxybenzonitrile was used as substrate. The temperature optimum determined was 45 °C for the surface-displayed enzyme instead of 35 °C for the purified enzyme. In addition, the optimum activity of the displayed nitrilase was shifted to more acidic pH in comparison to the free enzyme.

Keywords

Autodisplay Nitrilase Bromoxynil Biocatalyst Surface display Biodeterioration 

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Christian Detzel
    • 1
    • 2
  • Ruth Maas
    • 1
    • 2
  • Agne Tubeleviciute
    • 1
  • Joachim Jose
    • 1
  1. 1.Institut für Pharmazeutische und Medizinische ChemieWestfälische Wilhelms-UniversitätMünsterGermany
  2. 2.Autodisplay Biotech GmbHDüsseldorfGermany

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