Suppressing Erwinia carotovora pathogenicity by projecting N-acyl homoserine lactonase onto the surface of Pseudomonas putida cells

J Microbiol Biotechnol. 2011 Dec;21(12):1330-5. doi: 10.4014/jmb.1107.07011.

Abstract

N-Acyl homoserine lactones (AHLs) serve as the vital quorum-sensing signals that regulate the virulence of the pathogenic bacterium Erwinia carotovora. In the present study, an approach to efficiently restrain the pathogenicity of E. carotovora-induced soft rot disease is described. Bacillus thuringiensis-derived N-acyl homoserine lactonase (AiiA) was projected onto the surface of Pseudomonas putida cells, and inoculation with both strains was challenged. The previously identified N-terminal moiety of the ice nucleation protein, InaQ-N, was applied as the anchoring motif. A surface display cassette with inaQ-N/ aiiA was constructed and expressed under the control of a constitutive promoter in P. putida AB92019. Surface localization of the fusion protein was confirmed by Western blot analysis, flow cytometry, and immunofluorescence microscopy. The antagonistic activity of P. putida MB116 expressing InaQ-N/AiiA toward E. carotovora ATCC25270 was evaluated by challenge inoculation in potato slices at different ratios. The results revealed a remarkable suppressing effect on E. carotovora infection. The active component was further analyzed using different cell fractions, and the cell surface-projected fusion protein was found to correspond to the suppressing effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibiosis
  • Bacillus thuringiensis / enzymology*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Carboxylic Ester Hydrolases / genetics*
  • Carboxylic Ester Hydrolases / metabolism
  • Down-Regulation*
  • Gene Expression*
  • Pectobacterium carotovorum / pathogenicity*
  • Pectobacterium carotovorum / physiology
  • Plant Diseases / microbiology*
  • Pseudomonas putida / genetics*
  • Pseudomonas putida / physiology
  • Solanum tuberosum / microbiology

Substances

  • Bacterial Proteins
  • Carboxylic Ester Hydrolases
  • N-acyl homoserine lactonase