Estimating biodegradative gene numbers at a JP-5 contaminated site using PCR

Area of Science:

• Environmental microbiology
• Molecular ecology
• Bioremediation

Background:

• Jet fuel (JP-5) contamination poses environmental challenges.
• Bioremediation is a promising cleanup strategy, but its effectiveness can be limited by microbial genetic potential and environmental factors.
• Understanding the microbial community's capacity for degradation is crucial for optimizing remediation efforts.

Purpose of the Study:

• To assess the gene numbers and biodegradative potential of microbial communities at a JP-5 contaminated site during bioremediation.
• To determine if a lack of genetic potential for bioremediation contributes to low oxygen utilization.
• To evaluate the utility of molecular techniques in assessing biodegradative potential in situ.

Main Methods:

• Utilized most-probable-number polymerase chain reaction (MPN-PCR) for gene quantification.
• Extracted total community DNA from soil samples.
• Performed PCR to detect genes (nahAc, alky, xylE) involved in JP-5 constituent degradation.

Main Results:

• Significant aromatic biodegradative potential was detected at both remediated and un-remediated sites.
• Genes xylE and nahAc were frequently detected, indicating substantial potential for degrading aromatic compounds.
• The gene alky was rarely detected, suggesting limited potential for degrading specific JP-5 components.
• Results suggest that physical or chemical factors, likely oxygen delivery, are limiting bioremediation, not microbial genetic capacity.

Conclusions:

• The microbial community possesses inherent biodegradative potential for JP-5 constituents.
• Low oxygen availability is a probable limiting factor for bioremediation at the studied site.
• Molecular techniques like MPN-PCR are valuable tools for evaluating biodegradative potential during active bioremediation.