Biodegradation during contaminant transport in porous media: 7. Impact of multiple-degrader community dynamics.

The biodegradation and transport of phenanthrene in porous media containing multiple populations of phenanthrene degraders is examined with a series of miscible-displacement experiments. A long-term experiment was conducted with a soil containing an indigenous microbial community comprised of 25 identified phenanthrene-degrading isolates. The rate and magnitude of phenanthrene biodegradation oscillated throughout the six-month experiment.

Influence of hydroxypropyl-beta-cyclodextrin (HPCD) on the bioavailability and biodegradation of pyrene.

It is well known that the limited aqueous solubilities of polycyclic aromatic hydrocarbons (PAH) often reduce their bioavailability to bacterial populations. The objective of this study was to test the impact of a solubility-enhancement reagent, hydroxypropyl-beta-cyclodextrin (HPCD), on the bioavailability and biodegradation of pyrene. No measurable loss of pyrene occurred for the control vials throughout the first 22 weeks of the experiment, indicating the absence of mass loss via abiotic transformation and volatilization.

Temporal change in culturable phenanthrene degraders in response to long-term exposure to phenanthrene in a soil column system.

Widespread environmental contamination by polycyclic aromatic hydrocarbons (PAH) has led to increased interest in the use of natural attenuation as a clean-up strategy. However, few bioremediation studies have investigated the behaviour of the indigenous PAH-degrading community after long-term exposure to a PAH. In this study, a column packed with sandy loam soil was exposed to a solution saturated with phenanthrene ( approximately 1.

Application of a reverse transcription-PCR assay to monitor regulation of the catabolic nahAc gene during phenanthrene degradation.

Biodegradation of polycyclic aromatic hydrocarbons (PAH), such as phenanthrene, in environmental samples is often limited by low bioavailability which results from a combination of low aqueous solubility and/or high sorption. The purpose of this study was to investigate the influence of agents that increase PAH bioavailability on expression of the PAH catabolic gene nahAc. Phenanthrene was used as a model PAH and Pseudomonasputida PpG7, which contains the NAH7 plasmid that encodes the genes responsible for naphthalene and phenanthrene degradation, was used as a model degrader.