Formation of structured communities by natural and transgenic naphthalene-degrading bacteria

This study concerns the formation of structured communities by monocultures and binary associations of Pseudomonas fluorescens transgenic strains and natural heterotrophic bacterial species in naphthalene-containing media with various osmotic pressures. It was shown that cells of P. fluorescens strain 5RL, harboring a recombinant construct in the chromosome, were more resistant to the combined action of the stress factors under study than P. fluorescens 82/pUTK21, harboring a recombinant construct within a plasmid. Natural P. fluorescens 1 strains, particularly Vibrio sp. 14, were more viable at high osmotic pressures and naphthalene concentrations. Experiments with the combined introduction of transgenic and natural bacterial strains at high osmotic pressures demonstrated the stable coexistence of bacterial associations in biofilms, independent of naphthalene concentration. Strains considered for introduction into the environment for bioremediation should be assessed with regard to their susceptibility to the combined effect of anthropogenic and natural stress factors. The design of bacterial associations for the same purpose should take into account the effect of factors important for their survival in polluted areas.