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A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems
Published on: December 24, 2014
Bioavailability and biodegradation of polycyclic aromatic hydrocarbons in soils
M J Smith1, G Lethbridge, R G Burns
1Research School of Biosciences, University of Kent, Canterbury, UK.
FEMS Microbiology Letters
|July 1, 1997
Summary
Soil bacteria inoculation significantly accelerated the breakdown of polycyclic aromatic hydrocarbons like phenanthrene and pyrene. Naphthalene degradation remained unaffected by bacterial addition in both sand and organic soil types.
Area of Science:
- Environmental microbiology
- Bioremediation
- Soil science
Background:
- Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants found in various environments.
- Understanding microbial degradation pathways is crucial for developing effective remediation strategies.
- The efficacy of specific bacterial inoculants in accelerating PAH mineralization in different soil types requires further investigation.
Purpose of the Study:
- To evaluate the impact of bacterial inoculation on the mineralization rates of phenanthrene, pyrene, and naphthalene in pristine sand and organic soils.
- To compare the effectiveness of a Gram-negative rod (PD2) and a four-membered bacterial consortium (DC1) in enhancing PAH biodegradation.
- To determine the half-lives and extent of mineralization for different PAHs under inoculated and non-inoculated conditions.
Main Methods:
- Soil microcosms were established using pristine sand and organic soil.
- Microcosms were inoculated with either a Gram-negative rod (PD2) or a four-membered consortium (DC1).
- Mineralization of phenanthrene, pyrene, and naphthalene was monitored by measuring CO2 evolution over time, and half-lives were calculated.
Main Results:
- Bacterial inoculation significantly accelerated phenanthrene and pyrene mineralization in both soil types, while naphthalene mineralization was unaffected.
- The half-life of phenanthrene decreased from over 80 days to approximately 3-7 days upon inoculation with PD2 or DC1.
- DC1 inoculation also accelerated pyrene mineralization, reducing its half-life from over 150 days to 18-33 days.
Conclusions:
- Specific bacterial inoculants, PD2 and DC1, can significantly enhance the biodegradation of recalcitrant PAHs like phenanthrene and pyrene in soil.
- The effectiveness of bacterial inoculation varies depending on the specific PAH and the bacterial strain or consortium used.
- These findings highlight the potential of tailored microbial strategies for the bioremediation of PAH-contaminated soils.
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