Development and utilisation of a medium to isolate phenanthrene-degrading Pseudomonas spp

Area of Science:

• Environmental microbiology
• Bioremediation
• Bacterial taxonomy

Background:

• Phenanthrene is a polycyclic aromatic hydrocarbon pollutant.
• Bioremediation using microorganisms is a sustainable approach for pollutant degradation.
• Pseudomonas species are known for their metabolic versatility and degradative capabilities.

Purpose of the Study:

• To isolate and identify phenanthrene-degrading bacteria from soil.
• To develop an efficient method for isolating specific bacterial degraders.
• To investigate the presence of phenanthrene degraders in different soil types.

Main Methods:

• Combined selective media (Gould S1 with sodium lauryl sarcosine and trimethoprim) with phenanthrene enrichment.
• Isolated bacteria from the rhizosphere of barley roots.
• Utilized analytical profile index (API) test system and classic taxonomic tests for identification.
• Compared bacterial populations in soil from a former coal gasification site and agricultural soil.

Main Results:

• Successfully isolated 23 phenanthrene degraders belonging to Pseudomonas spp. in a single step.
• Identified all isolates as members of the Pseudomonas RNA homology group I.
• Found phenanthrene degraders predominantly in the coal gasification site soil, absent in agricultural soil.
• Observed differences in rhizosphere-attached Pseudomonas spp. between the two soil types.

Conclusions:

• A novel, efficient method was developed for isolating phenanthrene-degrading Pseudomonas spp.
• The study highlights the presence and abundance of specific degraders in contaminated environments.
• Results suggest that soil history and management practices influence the distribution of pollutant-degrading bacteria.