Advertisement

Tactic responses to pollutants and their potential to increase biodegradation efficiency

Authors

  • J. Lacal,

    1. Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
    Search for more papers by this author
  • J.A. Reyes-Darias,

    1. Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
    Search for more papers by this author
  • C. García-Fontana,

    1. Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
    Search for more papers by this author
  • J.-L. Ramos,

    1. Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
    Search for more papers by this author
  • T. Krell

    Corresponding author
    • Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
    Search for more papers by this author

Correspondence

Tino Krell, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/Prof. Albareda 1, 18008 Granada, Spain. E-mail: tino.krell@eez.csic.es

Summary

A significant number of bacterial strains are able to use toxic aromatic hydrocarbons as carbon and energy sources. In a number of cases, the evolution of the corresponding degradation pathway was accompanied by the evolution of tactic behaviours either towards or away from these toxic carbon sources. Reports are reviewed which show that a chemoattraction to heterogeneously distributed aromatic pollutants increases the bioavailability of these compounds and their biodegradation efficiency. An extreme form of chemoattraction towards aromatic pollutants, termed ‘hyperchemotaxis’, was described for Pseudomonas putida DOT-T1E, which is based on the action of the plasmid-encoded McpT chemoreceptor. Cells with this phenotype were found of being able to approach and of establishing contact with undiluted crude oil samples. Although close McpT homologues are found on other degradation plasmids, the sequence of their ligand-binding domains does not share significant similarity with that of NahY, the other characterized chemoreceptor for aromatic hydrocarbons. This may suggest the existence of at least two families of chemoreceptors for aromatic pollutants. The use of receptor chimers comprising the ligand-binding region of McpT for biosensing purposes is discussed.

Ancillary