Aerobic phenanthrene biodegradation in a two-phase partitioning bioreactor

Area of Science:

• Environmental Microbiology
• Biotechnology
• Bioremediation

Background:

• Phenanthrene is a polycyclic aromatic hydrocarbon pollutant.
• Bioreactors offer controlled environments for microbial degradation.
• Oxygen availability is crucial for aerobic biodegradation.

Purpose of the Study:

• To investigate phenanthrene aerobic degradation by Pseudomonas migulae.
• To compare mechanical aeration with photosynthetic oxygenation in a two-phase partitioning bioreactor (TPPB).
• To evaluate the impact of aeration/agitation rates and light intensity on biodegradation.

Main Methods:

• Utilized a two-phase partitioning bioreactor (TPPB) with silicone oil as the organic phase.
• Employed a Pseudomonas migulae strain for phenanthrene degradation.
• Investigated two oxygenation strategies: classical mechanical aeration and photosynthetic oxygenation using Chlorella sorokiniana.
• Varied aeration rates, agitation speeds, and light illuminance.

Main Results:

• Mechanical aeration significantly enhanced phenanthrene biodegradation rates.
• Phenanthrene removal rates increased with higher aeration and agitation in mechanical aeration, reaching up to 36 +/- 2 mg/l h.
• Photosynthetic oxygenation achieved a maximum rate of 8.1 +/- 1.2 mg/l h under optimal conditions (200 rpm, 8000 lux).

Conclusions:

• Mechanical aeration is more effective for enhancing phenanthrene biodegradation in this TPPB system.
• Optimizing physical parameters like aeration and agitation is key for efficient bioremediation.
• Photosynthetic oxygenation presents a potential alternative but requires further optimization for high-rate degradation.