Enhanced tolerance to naphthalene and enhanced rhizoremediation performance for Pseudomonas putida KT2440 via the NAH7 catabolic plasmid

Appl Environ Microbiol. 2012 Aug;78(15):5104-10. doi: 10.1128/AEM.00619-12. Epub 2012 May 11.

Abstract

In this work, we explore the potential use of the Pseudomonas putida KT2440 strain for bioremediation of naphthalene-polluted soils. Pseudomonas putida strain KT2440 thrives in naphthalene-saturated medium, establishing a complex response that activates genes coding for extrusion pumps and cellular damage repair enzymes, as well as genes involved in the oxidative stress response. The transfer of the NAH7 plasmid enables naphthalene degradation by P. putida KT2440 while alleviating the cellular stress brought about by this toxic compound, without affecting key functions necessary for survival and colonization of the rhizosphere. Pseudomonas putida KT2440(NAH7) efficiently expresses the Nah catabolic pathway in vitro and in situ, leading to the complete mineralization of [(14)C]naphthalene, measured as the evolution of (14)CO(2), while the rate of mineralization was at least 2-fold higher in the rhizosphere than in bulk soil.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodegradation, Environmental
  • Carbon Dioxide / analysis
  • Carbon Radioisotopes / analysis
  • Carbon Radioisotopes / metabolism
  • Conjugation, Genetic / genetics
  • Drug Tolerance / genetics
  • Drug Tolerance / physiology*
  • Microarray Analysis
  • Naphthalenes / metabolism
  • Naphthalenes / toxicity*
  • Oxidative Stress / genetics
  • Plant Roots / metabolism*
  • Plant Roots / microbiology
  • Plasmids / genetics
  • Pseudomonas putida / genetics
  • Pseudomonas putida / physiology*
  • Soil Pollutants / toxicity*

Substances

  • Carbon Radioisotopes
  • Naphthalenes
  • Soil Pollutants
  • Carbon Dioxide
  • naphthalene