Metabolism-dependent taxis towards (methyl)phenols is coupled through the most abundant of three polar localized Aer-like proteins of Pseudomonas putida

Environ Microbiol. 2008 May;10(5):1320-34. doi: 10.1111/j.1462-2920.2007.01546.x. Epub 2008 Feb 12.

Abstract

Comparatively little is known about directed motility of environmental bacteria to common aromatic pollutants. Here, by expressing different parts of a (methyl)phenol-degradative pathway and the use of specific mutants, we show that taxis of Pseudomonas putida towards (methyl)phenols is dictated by its ability to catabolize the aromatic compound. Thus, in contrast to previously described chemoreceptor-mediated chemotaxis mechanisms towards benzoate, naphthalene and toluene, taxis in response to (methyl)phenols is mediated by metabolism-dependent behaviour. Here we show that P. putida differentially expresses three Aer-like receptors that are all polar-localized through interactions with CheA, and that inactivation of the most abundant Aer2 protein significantly decreases taxis towards phenolics. In addition, the participation of a sensory signal transduction protein composed of a PAS, a GGDEF and an EAL domain in motility towards these compounds is demonstrated. The results are discussed in the context of the versatility of metabolism-dependent coupling and the necessity for P. putida to integrate diverse metabolic signals from its native heterogeneous soil and water environments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cell Polarity*
  • Chemotaxis*
  • Gene Expression Regulation, Bacterial*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Methyl-Accepting Chemotaxis Proteins
  • Molecular Sequence Data
  • Mutation
  • Phenols* / chemistry
  • Phenols* / metabolism
  • Plasmids / genetics
  • Pseudomonas / genetics
  • Pseudomonas / metabolism*
  • Pseudomonas / physiology
  • Signal Transduction*

Substances

  • Bacterial Proteins
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • Phenols