Bacteria-mediated PAH degradation in soil and sediment

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the natural environment and easily accumulate in soil and sediment due to their low solubility and high hydrophobicity, rendering them less available for biological degradation. However, microbial degradation is a promising mechanism which is responsible for the ecological recovery of PAH-contaminated soil and sediment for removing these recalcitrant compounds compared with chemical degradation of PAHs. The goal of this review is to provide an outline of the current knowledge of biodegradation of PAHs in related aspects. Over 102 publications related to PAH biodegradation in soil and sediment are compiled, discussed, and analyzed. This review aims to discuss PAH degradation under various redox potential conditions, the factors affecting the biodegradation rates, degrading bacteria, the relevant genes in molecular monitoring methods, and some recent-year bioremediation field studies. The comprehensive understanding of the bioremediation kinetics and molecular means will be helpful for optimizing and monitoring the process, and overcoming its limitations in practical projects.

Effect of Pollution on Aquatic Microbial Diversity

“…Additionally, the authors found a significant fall in phenanthrene concentration in the spiked sediments which was linked to bacterial metabolism based on quantification of activity of genes (xylE and phnAc dioxygenase genes) involved in PAH degradation. A significant number of papers have been published in the last 10 years which have looked into aspects of isolation of novel bacterial strains from diverse environments including sediments contaminated with PAH compounds (e.g., review by Lu et al 2011).…”

Remediation of oil spills in temperate and tropical coastal marine environments

“…With changes in salinity, the microbial population can sometimes change resulting in less diversity. It has been demonstrated that as salinity increases the degradation rates of hydrocarbons decrease (Atlas 1981) as was the inhibition of degradation of PAHs (polycyclic aromatic hydrocarbons) (Lu et al 2011). The pH in environments is variable depending on the type, in which wetlands tend to have a lower pH, whereas mineral soils have a more neutral or slightly higher pH (Venosa and Zhu 2003).…”

Enhancement of nitrate-induced bioremediation in marine sediments contaminated with petroleum hydrocarbons by using microemulsions

“…Nitrate-induced bioremediation has been shown to be an attractive option for remediating the contaminated marine sediment (Hutchins 1991;Wilson et al 1997;Hutchins et al 1998;Shao et al 2010). Nitrate, as an electron acceptor in nitrateinduced bioremediation, is more than ten thousand times more soluble than oxygen in terms of electron-accepting capacity, and it can yield free energy almost as much as that under aerobic conditions (Lu et al 2011). Previous studies have revealed that NO 3 − stimulated the growth of both heterotrophic and autotrophic denitrifiers, and the former can out-compete sulfate-reducing bacteria for organics degradation (Eq.…”

“…One of the possible reasons that lead to the low biodegradation efficiency of petroleum hydrocarbons especially the high molecular weight fractions is their low solubility (Villemur et al 2000;Lu et al 2011), which makes them present as non-aqueous pollutant liquids (NAPL) (Martienssen and Schirmer 2007). The organic pollutants can be mainly degraded by microorganisms or some specific enzymes present in solutions, where they are available for microbial action.…”