Characterization of polycyclic aromatic hydrocarbons degradative soil Pseudomonas

Area of Science:

• Environmental Microbiology
• Bioremediation
• Molecular Biology

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants.
• Bioremediation using microorganisms is a promising strategy for PAH removal.
• Understanding the genetic basis of PAH degradation in bacteria is crucial for optimizing bioremediation.

Purpose of the Study:

• To isolate and characterize Pseudomonas strains capable of degrading PAHs.
• To investigate the genetic basis and transferability of naphthalene and phenanthrene degradation genes.
• To explore the potential of these strains for bioremediation applications.

Main Methods:

• Isolation of Pseudomonas strains from oil sludge-contaminated soil.
• Enrichment cultures using naphthalene as a sole carbon source.
• Bacterial conjugation experiments to assess gene transferability.
• Naphthalene and phenanthrene degradation assays.

Main Results:

• Nine Pseudomonas strains capable of degrading naphthalene and phenanthrene were isolated.
• The naphthalene (Nah) degradation function was transferable via conjugation in some strains.
• Evidence suggests that Nah and phenanthrene (Phn) degradation functions are linked and plasmid-encoded.
• Some transconjugants lost the Oct character, indicating plasmidic inheritance.

Conclusions:

• Pseudomonas strains isolated from oil sludge possess the capability to degrade key PAHs.
• The linked naphthalene and phenanthrene degradation pathways are likely encoded on transferable plasmids.
• These findings contribute to understanding microbial PAH degradation mechanisms and hold potential for bioremediation strategies.