Degradation Of Aromatic Hydrocarbons Research Articles

Endophytic bacterial diversity in the latex-bearing caulosphere of Hevea brasiliensis Müll. Arg.

Rubber trees are a commercial cash crop, and the milky latex or polyisoprene they produce is the natural source of rubber. Little is known about the bacterial populations found in active zone of latex-bearing caulosphere. We employed a tailored cloud microbial bioinformatic approach for the identification and potential hypothetical ecological roles of an uncultured endophytic hidden bacterial community in the active zone of the latex-bearing caulosphere of Hevea brasiliensis. Small pieces of slivers were collected from healthy plant from the village: Belonia, South Tripura, rubber plantation in Northeastern India. These uncultured bacteria were identified using the V3-V4 hypervariable amplicon region of the 16S rDNA gene. A total of 209,586 contigs have been generated. EasyMAP Version 1.0, a cloud-based microbial bioinformatics tool with an integrated QIIME2 pipeline, was used to analyze contigs. We detected 15 phyla and 91 OTUs (operational taxonomic units). Proteobacteria (73.5%) was the most enriched phylum, followed by Firmicutes (13.8%), Bacteroidetes (5.2%), and Actinobacteria (3.2%). Ammonia oxidizers, sulfate reducers, dehalogenation, chitin degradation, nitrite reducers, and aromatic hydrocarbon degraders were the most prevalent functional categories in the active zones of caulosphere. Furthermore, Gammaproteobacteria (49.2%) and Erwinia (29.19%) were the most abundant classes and genera of endophytic bacterial communities. Thus, the presence of a substantial amount of phosphate-solubilizing Gammaproteobacteria (PSB) may stimulate growth, increase plant resilience, suppress disease, and aid in the rubber and sugar breakdown. This is the first report of microbial endophytes associated with Hevea caulosphere.

Determination of soil phenanthrene degradation through a fungal-bacterial consortium.

Fungal-bacterial consortia enhance organic pollutant removal, but the underlying mechanisms are unclear. We used stable isotope probing (SIP) to explore the mechanism of bioaugmentation involved in polycyclic aromatic hydrocarbon (PAH) biodegradation in petroleum-contaminated soil by introducing the indigenous fungal strain Aspergillus sp. LJD-29 and the bacterial strain Pseudomonas XH-1. While each strain alone increased phenanthrene (PHE) degradation, the simultaneous addition of both strains showed no significant enhancement compared to treatment with XH-1 alone. Nonetheless, the assimilation effect of microorganisms on PHE was significantly enhanced. SIP revealed a role of XH-1 in PHE degradation, while the absence of LJD-29 in 13C-DNA indicated a supporting role. The correlations between fungal abundance, degradation efficiency, and soil extracellular enzyme activity indicated that LJD-29, while not directly involved in PHE assimilation, played a crucial role in the breakdown of PHE through extracellular enzymes, facilitating the assimilation of metabolites by bacteria. This observation was substantiated by the results of metabolite analysis. Furthermore, the combination of fungus and bacterium significantly influenced the diversity of PHE degraders. Taken together, this study highlighted the synergistic effects of fungi and bacteria in PAH degradation, revealed a new fungal-bacterial bioaugmentation mechanism and diversity of PAH-degrading microorganisms, and provided insights for in situ bioremediation of PAH-contaminated soil.IMPORTANCEThis study was performed to explore the mechanism of bioaugmentation by a fungal-bacterial consortium for phenanthrene (PHE) degradation in petroleum-contaminated soil. Using the indigenous fungal strain Aspergillus sp. LJD-29 and bacterial strain Pseudomonas XH-1, we performed stable isotope probing (SIP) to trace active PHE-degrading microorganisms. While inoculation of either organism alone significantly enhanced PHE degradation, the simultaneous addition of both strains revealed complex interactions. The efficiency plateaued, highlighting the nuanced microbial interactions. SIP identified XH-1 as the primary contributor to in situ PHE degradation, in contrast to the limited role of LJD-29. Correlations between fungal abundance, degradation efficiency, and extracellular enzyme activity underscored the pivotal role of LJD-29 in enzymatically facilitating PHE breakdown and enriching bacterial assimilation. Metabolite analysis validated this synergy, unveiling distinct biodegradation mechanisms. Furthermore, this fungal-bacterial alliance significantly impacted PHE-degrading microorganism diversity. These findings advance our understanding of fungal-bacterial bioaugmentation and microorganism diversity in polycyclic aromatic hydrocarbon (PAH) degradation as well as providing insights for theoretical guidance in the in situ bioremediation of PAH-contaminated soil.

Biomolecular condensates of Chlorocatechol 1,2-Dioxygenase as prototypes of enzymatic microreactors for the degradation of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are molecules with two or more fused aromatic rings that occur naturally in the environment due to incomplete combustion of organic substances. However, the increased demand for fossil fuels in recent years has increased anthropogenic activity, contributing to the environmental concentration of PAHs. The enzyme chlorocatechol 1,2-dioxygenase from Pseudomonas putida (Pp 1,2-CCD) is responsible for the breakdown of the aromatic ring of catechol, making it a potential player in bioremediation strategies. Pp 1,2-CCD can tolerate a broader range of substrates, including halogenated compounds, than other dioxygenases. Here, we report the construction of a chimera protein able to form biomolecular condensates with potential application in bioremediation. The chimera protein was built by conjugating Pp 1,2-CCD to low complex domains (LCDs) derived from the DEAD-box protein Dhh1. We showed that the chimera could undergo liquid-liquid phase separation (LLPS), forming a protein-rich liquid droplet under different conditions (variable protein and PEG8000 concentrations and pH values), in which the protein maintained its structure and main biophysical properties. The condensates were active against 4-chlorocatechol, showing that the chimera droplets preserved the enzymatic activity of the native protein. Therefore, it constitutes a prototype of a microreactor with potential use in bioremediation.

Fine-tuning an aromatic ring-hydroxylating oxygenase to degrade high molecular weight polycyclic aromatic hydrocarbon

Rieske nonheme iron aromatic ring-hydroxylating oxygenases (RHOs) play pivotal roles in determining the substrate preferences of polycyclic aromatic hydrocarbon (PAH) degraders. However, their potential to degrade high molecular weight PAHs (HMW-PAHs) has been relatively unexplored. NarA2B2 is an RHO derived from a thermophilic Hydrogenibacillus sp. strain N12. In this study, we have identified four “hotspot” residues (V236, Y300, W316, and L375) that may hinder the catalytic capacity of NarA2B2 when it comes to HMW-PAHs. By employing structure-guided rational enzyme engineering, we successfully modified NarA2B2, resulting in NarA2B2 variants capable of catalyzing the degradation of six different types of HMW-PAHs, including pyrene, fluoranthene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene. Three representative variants, NarA2B2W316I, NarA2B2Y300F-W316I, and NarA2B2V236A-W316I-L375F, not only maintain their abilities to degrade low molecular weight PAHs (LMW-PAHs), but also exhibited 2-4 times higher degradation efficiency for HMW-PAHs in comparison to another isozyme, NarAaAb. Computational analysis of the NarA2B2 variants predict that these modifications altering the size and hydrophobicity of the active site pocket making it more suitable for HMW-PAHs. These findings provide a comprehensive understanding of the relationship between three-dimensional structure and functionality, thereby opening up possibilities for designing improved RHOs that can be more effectively used in the bioremediation of PAHs.

Field-aged rice hull biochar stimulated the methylation of mercury and altered the microbial community in a paddy soil under controlled redox condition changes

Mercury (Hg) contaminated paddy soils are hot spots for methylmercury (MeHg) which can enter the food chain via rice plants causing high risks for human health. Biochar can immobilize Hg and reduce plant uptake of MeHg. However, the effects of biochar on the microbial community and Hg (de)methylation under dynamic redox conditions in paddy soils are unclear. Therefore, we determined the microbial community in an Hg contaminated paddy soil non-treated and treated with rice hull biochar under controlled redox conditions (< 0 mV to 600 mV) using a biogeochemical microcosm system. Hg methylation exceeded demethylation in the biochar-treated soil. The aromatic hydrocarbon degraders Phenylobacterium and Novosphingobium provided electron donors stimulating Hg methylation. MeHg demethylation exceeded methylation in the non-treated soil and was associated with lower available organic matter. Actinobacteria were involved in MeHg demethylation and interlinked with nitrifying bacteria and nitrogen-fixing genus Hyphomicrobium. Microbial assemblages seem more important than single species in Hg transformation. For future directions, the demethylation potential of Hyphomicrobium assemblages and other nitrogen-fixing bacteria should be elucidated. Additionally, different organic matter inputs on paddy soils under constant and dynamic redox conditions could unravel the relationship between Hg (de)methylation, microbial carbon utilization and nitrogen cycling.

Degradation and mechanism of PAHs by Fe-based activated persulfate: Effect of temperature and noble metal

The accumulation of contaminants like PAHs in soil due to industrialization, urbanization, and intensified agriculture poses environmental challenges, owing to their persistence, hydrophobic nature, and toxicity. Thus, the degradation of PAHs has attracted worldwide attention in soil remediation. This study explored the effect of noble metal and temperature on the degradation of various polycyclic aromatic hydrocarbons (PAHs) in soil, as well as the types of reactive radicals generated and mechanism. The Fe-Pd/AC and Fe-Pt/AC activated persulfate exhibited high removal efficiency of 19 kinds of PAHs, about 79.95 % and 83.36 %, respectively. Fe-Pt/AC-activated persulfate exhibits superior degradation efficiency than that on Fe-Pd/AC-activated persulfate, due to the higher specific surface area and dispersity of Pt particles, thereby resulting in increased reactive radicals (·OH, SO4−· and ·OOH). Additionally, thermal activation enhances the degradation of PAHs, with initial efficiencies of 64.20 % and 55.49 % on Fe-Pd/AC- and Fe-Pt/AC-activated persulfate systems respectively, increasing to 76.05 % and 73.14 % with elevated temperatures from 21.5 to 50 °C. Metal and thermal activation facilitate S2O82− activation, generating reactive radicals, crucial for the degradation of PAHs via ring opening and oxygen hydrogenation reactions, yielding low-ring oxygen-containing derivatives such as organic acids, keto compounds, ethers, and esters. Furthermore, understanding the impact of parameters such as activation temperature and the types of noble metals on the degradation of PAHs within the activated persulfate system provides a theoretical foundation for the remediation of PAH-contaminated soil.

Differential degradation of petroleum hydrocarbons by Shewanella putrefaciens under aerobic and anaerobic conditions.

The complexity of crude oil composition, combined with the fluctuating oxygen level in contaminated environments, poses challenges for the bioremediation of oil pollutants, because of compound-specific microbial degradation of petroleum hydrocarbons under certain conditions. As a result, facultative bacteria capable of breaking down petroleum hydrocarbons under both aerobic and anaerobic conditions are presumably effective, however, this hypothesis has not been directly tested. In the current investigation, Shewanella putrefaciens CN32, a facultative anaerobic bacterium, was used to degrade petroleum hydrocarbons aerobically (using O2 as an electron acceptor) and anaerobically (using Fe(III) as an electron acceptor). Under aerobic conditions, CN32 degraded more saturates (65.65 ± 0.01%) than aromatics (43.86 ± 0.03%), with the following order of degradation: dibenzofurans > n-alkanes > biphenyls > fluorenes > naphthalenes > alkylcyclohexanes > dibenzothiophenes > phenanthrenes. In contrast, under anaerobic conditions, CN32 exhibited a higher degradation of aromatics (53.94 ± 0.02%) than saturates (23.36 ± 0.01%), with the following order of degradation: dibenzofurans > fluorenes > biphenyls > naphthalenes > dibenzothiophenes > phenanthrenes > n-alkanes > alkylcyclohexanes. The upregulation of 4-hydroxy-3-polyprenylbenzoate decarboxylase (ubiD), which plays a crucial role in breaking down resistant aromatic compounds, was correlated with the anaerobic degradation of aromatics. At the molecular level, CN32 exhibited a higher efficiency in degrading n-alkanes with low and high carbon numbers relative to those with medium carbon chain lengths. In addition, the degradation of polycyclic aromatic hydrocarbons (PAHs) under both aerobic and anaerobic conditions became increasingly difficult with increased numbers of benzene rings and methyl groups. This study offers a potential solution for the development of targeted remediation of pollutants under oscillating redox conditions.

Native freshwater lake microbial community response to an in situ experimental dilbit spill.

With the increase in crude oil transport throughout Canada, the potential for spills into freshwater ecosystems has increased and additional research is needed in these sensitive environments. Large enclosures erected in a lake were used as mesocosms for this controlled experimental dilbit (diluted bitumen) spill under ambient environmental conditions. The microbial response to dilbit, the efficacy of standard remediation protocols on different shoreline types commonly found in Canadian freshwater lakes, including a testing of a shoreline washing agent were all evaluated. We found that the native microbial community did not undergo any significant shifts in composition after exposure to dilbit or the ensuing remediation treatments. Regardless of the treatment, sample type (soil, sediment, or water), or type of associated shoreline, the community remained relatively consistent over a 3-month monitoring period. Following this, metagenomic analysis of polycyclic aromatic and alkane hydrocarbon degradation mechanisms also showed that while many key genes identified in PAH and alkane biodegradation were present, their abundance did not change significantly over the course of the experiment. These results showed that the native microbial community present in a pristine freshwater lake has the prerequisite mechanisms for hydrocarbon degradation in place, and combined with standard remediation practices in use in Canada, has the genetic potential and resilience to potentially undertake bioremediation.

Polycyclic aromatic hydrocarbons degradation by free-air CO2 enriched (FACE) bacteria into low molecular easy to degrade organic compounds

Polycyclic aromatic hydrocarbons degradation by free-air CO2 enriched (FACE) bacteria into low molecular easy to degrade organic compounds

Efficiency of Hydrogen Peroxide and Fenton Reagent for Polycyclic Aromatic Hydrocarbon Degradation in Contaminated Soil: Insights from Experimental and Predictive Modeling

This study investigates the degradation kinetics of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil using hydrogen peroxide (H2O2) and the Fenton process (H2O2/Fe2+). The effect of oxidant concentration and the Fenton molar ratio on PAH decomposition efficiency is examined. Results reveal that increasing H2O2 concentration above 25 mmol/samples leads to a slight increase in the rate constants for both first- and second-order reactions. The Fenton process demonstrates higher efficiency in PAH degradation compared to H2O2 alone, achieving decomposition yields ranging from 84.7% to 99.9%. pH evolution during the oxidation process influences PAH degradation, with alkaline conditions favoring lower elimination rates. Fourier-transform infrared (FTIR) spectroscopy analysis indicates significant elimination of PAHs after treatment, with both oxidants showing comparable efficacy in complete hydrocarbon degradation. The mechanisms of PAH degradation by H2O2 and the Fenton process involve hydroxyl radical formation, with the latter exhibiting greater efficiency due to Fe2+ catalysis. Gaussian process regression (GPR) modeling accurately predicts reduced concentration, with optimized ARD-Exponential kernel function demonstrating superior performance. The Improved Grey Wolf Optimizer algorithm facilitates optimization of reaction conditions, yielding a high degree of agreement between experimental and predicted values. A MATLAB 2022b interface is developed for efficient optimization and prediction of C/C0, a critical parameter in PAH degradation studies. This integrated approach offers insights into optimizing the efficiency of oxidant-based PAH remediation techniques, with potential applications in contaminated soil remediation.

Arsenic effectively improves the degradation of fluorene by Rhodococcus sp. 2021 under the combined pollution of arsenic and fluorene

The performance of bacterial strains in executing degradative functions under the coexistence of heavy metals/heavy metal-like elements and organic contaminants is understudied. In this study, we isolated a fluorene-degrading bacterium, highly arsenic-resistant, designated as strain 2021, from contaminated soil at the abandoned site of an old coking plant. It was identified as a member of the genus Rhodococcus sp. strain 2021 exhibited efficient fluorene-degrading ability under optimal conditions of 400 mg/L fluorene, 30 °C, pH 7.0, and 250 mg/L trivalent arsenic. It was noted that the addition of arsenic could promote the growth of strain 2021 and improve the degradation of fluorene – a phenomenon that has not been described yet. The results further indicated that strain 2021 can oxidize As3+ to As5+; here, approximately 13.1% of As3+ was converted to As5+ after aerobic cultivation for 8 days at 30 °C. The addition of arsenic could greatly up-regulate the expression of arsR/A/B/C/D and pcaG/H gene clusters involved in arsenic resistance and aromatic hydrocarbon degradation; it also aided in maintaining the continuously high expression of cstA that codes for carbon starvation protein and prmA/B that codes for monooxygenase. These results suggest that strain 2021 holds great potential for the bioremediation of environments contaminated by a combination of arsenic and polycyclic aromatic hydrocarbons. This study provides new insights into the interactions among microbes, as well as inorganic and organic pollutants.

Metagenomics analysis of water samples collected from the Yamuna River of Agra city, India.

Yamuna River water in Agra city of India is contaminated with toxic pollutants, including heavy metals that cause damage to the environment and human health. At present, the direct use of river water for drinking purposes and household activities lead to the direct exposure of society to the contaminants. In this study, Yamuna River water samples were collected from three different sites in Agra city during the monsoon, summer, and winter seasons. The physico-chemical parameters were estimated along with heavy metals. In physico-chemical parameter, the values found were mostly above the permissible limits. The results water samples contain high levels of cadmium, chromium, lead, and nickel above the desirable levels in most cases. The metagenomic analysis revealed that Proteobacteria, Bacteroidetes, Verrucomicrobia, Actinobacteria, and Planctobacteria were the most abundant phyla with a relative abundance of 61%, 9.34%, 5.23%, 4.64%, and 4.3%, respectively. The Comamonadaceae, the most abundant family consists of the genera involved in hydrogen oxidation, iron reduction, degraders of polycyclic aromatic hydrocarbons, and fermentation. The presence of Pseudomonas, Nitrosomonas sp., Thauera humireducens and Dechloromonas denitrificans (decomposition of sewage and organic matter) and Pseudomonas aeruginosa indicates the presence of heavy metal degrading bacteria in water sample. Functional prediction showed the presence of genes responsible for different metabolic pathways that could help developing new bioremediation strategies. The study concludes the status of water contamination, the presence of complex microbial community and suggests the futuristic use and their role in bioremediation.

Role of keystone drives polycyclic aromatic hydrocarbons degradation and humification especially combined with aged contaminated soil in co-composting

Accumulation of persistent organic pollutants polycyclic aromatic hydrocarbons (PAHs) in soil has become a global problem. Composting is considered one of the more economical methods of soil remediation and is important for the resourceful use of wastes. Agroforestry waste is produced in huge amounts and is utilized at low rates, hence there is an urgent need to manage it. Here, leaf (LVS) or rice straw (SVS) was co-composting with aged contaminated soil to investigate bacteria interaction to PAHs degradation and humus formation. The degradation rate of high molecular weight PAHs (HMW-PAHs) in LVS and SVS reached 58.9% and 52.5%, and the low molecular weight PAHs (LMW-PAHs) were 77.5% and 65%. Meanwhile, the humus increased by 44.8% and 60.5% in LVS and SVS at the end of co-composting. The topological characteristics and community assembly of the bacterial community showed that LVS had higher complexity and more keystones than SVS, suggesting that LVS might more beneficial for the degradation of PAHs. The stability of the co-occurrence network and stochastic processes (dispersal limitation) dominated community assembly made SVS beneficial for humus formation. Mantel test and structural equation models indicated that the transformation of organic matter was important for PAHs degradation and humus formation. Degradation of HMW-PAHs led to bacterial succession, which affected the formation of precursors and ultimately increased the humus content. This study provided potential technology support for improving the quality of agroforestry organic waste composting and degrading PAHs in aged contaminated soil.

Efficient bio-remediation of multiple aromatic hydrocarbons using different types of thermotolerant, ring-cleaving dioxygenases derived from Aeribacillus pallidus HB-1

As toxic contaminants, aromatic compounds are widespread in most environmental matrices, and bioenzymatic catalysis plays a critical role in the degradation of xenobiotics. Here, a thermophillic aromatic hydrocarbon degrader Aeribacillus pallidus HB-1 was found. Bioinformatic analysis of the HB-1 genome revealed two ring-cleaving extradiol dioxygenases (EDOs), among which, EDO-0418 was assigned to a new subfamily of type I.1 EDOs and exhibited a broad substrate specificity, particularly towards biarylic substrate. Both EDOs exhibited optimal activities at elevated temperatures (55 and 65 °C, respectively) and showed remarkable thermostability, pH stability, metal ion resistance and tolerance to chemical reagents. Most importantly, simulated wastewater bioreactor experiments demonstrated efficient and uniform degradation performance of mixed aromatic substrates under harsh environments by the two enzymes combined for potential industrial applications. The unveiling of two thermostable dioxygenases with broad substrate specificities and stress tolerance provides a novel approach for highly efficient environmental bioremediation using composite enzyme systems.

Preparation of Ag3PO4/Bi2Zr2O7/MoS2 composite catalyst and its catalytic activity in the degradation of polycyclic aromatic hydrocarbons

Preparation of Ag3PO4/Bi2Zr2O7/MoS2 composite catalyst and its catalytic activity in the degradation of polycyclic aromatic hydrocarbons

Photocatalytic Degradation of Polycyclic Aromatic Hydrocarbons by Ag3PO4/MoS2 Composite

Photocatalytic Degradation of Polycyclic Aromatic Hydrocarbons by Ag3PO4/MoS2 Composite

Erratum for Walton and Buchan, "Evidence for novel polycyclic aromatic hydrocarbon degradation pathways in culturable marine isolates".

Erratum for Walton and Buchan, "Evidence for novel polycyclic aromatic hydrocarbon degradation pathways in culturable marine isolates".

Fabrication of pollution-free coal gangue-based catalytic material utilizing ferrous chloride as activator for efficient peroxymonosulfate activation

Novel coal gangue-based persulfate catalyst (CG-FeCl2) was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate (FeCl2·4H2O). The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated. It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds. And the main gaseous products are H2O, H2, and HCl during the heating process. Besides, the ability of CG-FeCl2 to activate peroxymonosulfate (PMS) for catalytic degradation of polycyclic aromatic hydrocarbons (PAHs) and phenol was deeply studied. More than 95% of naphthyl, phenanthrene and phenol were removed under optimizied conditions. In addition, 1O2, ·OH, and SO4·− were involved in the CG-FeCl2/PMS system from the free radical scavenging experiment, where 1O2 played a major role during the oxidation process. Furthermore, CG-FeCl2/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments. Overall, the novel CG-FeCl2 is an efficient and environmentally friendly catalyst, displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment.

Biosurfactants-based mixed polycyclic aromatic hydrocarbon degradation: From microbial community structure toward non-targeted metabolomic profile determination

Biosurfactants-based bioremediation is considered an efficient technology to eliminate environmental pollutants including polycyclic aromatic hydrocarbons (PAHs). However, the precise role of rhamnolipids or lipopeptide-biosurfactants in mixed PAH dissipation, shaping microbial community structure, and influencing metabolomic profile remained unclear. In this study, results showed that the maximum PAH degradation was achieved in lipopeptide-assisted treatment (SPS), where the pyrene and phenanthrene were substantially degraded up to 74.28 % and 63.05 % respectively, as compared to rhamnolipids (SPR) and un-aided biosurfactants (SP). Furthermore, the high throughput sequencing analysis revealed a significant change in the PAH-degrading microbial community, with Proteobacteria being the predominant phylum (>98 %) followed by Bacteroidota and Firmicutes in all the treatments. Moreover, Pseudomonas and Pannonibacter were found as highly potent bacterial genera for mixed PAH degradation in SPR, SPS, and SP treatments, nevertheless, the abundance of the genus Pseudomonas was significantly enhanced (>97 %) in SPR treatment groups. On the other hand, the non-targeted metabolomic profile through UHPLC-MS/MS exhibited a remarkable change in the metabolites of amino acids, carbohydrates, and lipid metabolisms by the input of rhamnolipids or lipopeptide-biosurfactants whereas, the maximum intensities of metabolites (more than two-fold) were observed in SPR treatment. The findings of this study suggested that the aforementioned biosurfactants can play an indispensable role in mixed PAH degradation as well as seek to offer new insights into shifts in PAH-degrading microbial communities and their metabolic function, which can guide the development of more efficient and targeted strategies for complete removal of organic pollutants such as PAH from the contaminated environment.

Evidence for novel polycyclic aromatic hydrocarbon degradation pathways in culturable marine isolates.

Polycyclic aromatic hydrocarbon (PAH) pollution is widespread throughout marine environments and significantly affects native flora and fauna. Investigating microbes responsible for degrading PAHs in these environments provides a greater understanding of natural attenuation in these systems. In addition, the use of culture-based approaches to inform bioinformatic and omics-based approaches is useful in identifying novel mechanisms of PAH degradation that elude genetic biomarker-based investigations. Furthermore, culture-based approaches allow for the study of PAH co-metabolism, which increasingly appears to be a prominent mechanism for PAH degradation in marine microbes.