scholarly journals CYP63A2, a Catalytically Versatile Fungal P450 Monooxygenase Capable of Oxidizing Higher-Molecular-Weight Polycyclic Aromatic Hydrocarbons, Alkylphenols, and Alkanes

2013 ◽  
Vol 79 (8) ◽  
pp. 2692-2702 ◽  
Author(s):  
Khajamohiddin Syed ◽  
Aleksey Porollo ◽  
Ying Wai Lam ◽  
Paul E. Grimmett ◽  
Jagjit S. Yadav
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Substrate Specificity ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Aliphatic Hydrocarbon ◽  
Ligand Docking ◽  
P450 Monooxygenase ◽  
Polycyclic Aromatic ◽  
Long Chain

ABSTRACTCytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons, albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungusPhanerochaete chrysosporiumthat was found to possess a broad oxidizing capability toward structurally diverse hydrocarbons belonging to mutagenic/carcinogenic fused-ring higher-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), endocrine-disrupting long-chain alkylphenols (APs), and crude oil aliphatic hydrocarbonn-alkanes. A homology-based three-dimensional (3D) model revealed the presence of an extraordinarily large active-site cavity in CYP63A2 compared to the mammalian PAH-oxidizing (CYP3A4, CYP1A2, and CYP1B1) and bacterial aliphatic-hydrocarbon-oxidizing (CYP101D and CYP102A1) P450s. This structural feature in conjunction with ligand docking simulations suggested potential versatility of the enzyme. Experimental characterization using recombinantly expressed CYP63A2 revealed its ability to oxidize HMW-PAHs of various ring sizes, including 4 rings (pyrene and fluoranthene), 5 rings [benzo(a)pyrene], and 6 rings [benzo(ghi)perylene], with the highest enzymatic activity being toward the 5-ring PAH followed by the 4-ring and 6-ring PAHs, in that order. Recombinant CYP63A2 activity yielded monohydroxylated PAH metabolites. The enzyme was found to also act as an alkane ω-hydroxylase that oxidizedn-alkanes with various chain lengths (C9to C12and C15to C19), as well as alkyl side chains (C3to C9) in alkylphenols (APs). CYP63A2 showed preferential oxidation of long-chain APs and alkanes. To our knowledge, this is the first P450 identified from any of the biological kingdoms that possesses such broad substrate specificity toward structurally diverse xenobiotics (PAHs, APs, and alkanes), making it a potent enzyme biocatalyst candidate to handle mixed pollution (e.g., crude oil spills).

scholarly journals Effective Removal of Alkanes and Polycyclic Aromatic Hydrocarbons by Bacteria from Soil Chronically Exposed to Crude Petroleum Oil

2021 ◽  
Author(s):  
Eman Afkar ◽  
Aly M. Hafez ◽  
Rashid I.H. Ibrahim ◽  
Munirah Aldayel
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Oil Spills ◽  
Practical Significance ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Polycyclic Aromatic ◽  
Long Chain

Abstract In this study, two bacterial strains isolated from an oil-contaminated soil, designated as AramcoS2 and AramcoS4 were able to degrade crude oil, long-chain n-alkanes of C10 to C20; (n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane n-nonadecane, and n-eicosane) and polycyclic aromatic hydrocarbons (PAHs) including biphenyl, naphthalene, and anthracene. Gas chromatography-mass spectrometry (GC-MS) technique was conducted to analyze and identify the crude oil residues after biodegradation. AramcoS2 and AramcoS4 were able to reduce the concentration of long-chain n-alkanes of C10-C20 efficiently on average by 77% of the original concentration. Both isolates could also degrade PAHs on average by 67% of the original concentration within 7 and 14 days of incubation at 30ºC, pH=6.8±0.2. The 16S rRNA gene sequences of AramcoS2 and S4 classified these isolates as Actinobacteria; well-known alkanes and PAHs degraders. The nucleotide sequences of AramcoS2 and AramcoS4 were submitted to the GenBank database under the accession numbers MN142506 and MN142551, respectively. Both isolates can be used to restore the environments contaminated with crude oil components. They should be of great practical significance both in bioremediation of soil contaminated with crude oil and bio-treatment of oil spills on surface water.

scholarly journals Evaluation of Polycyclic Aromatic Hydrocarbons and Total Petroleum Hydrocarbons Profiles in Some Nigerian Crude Oils

2019 ◽  
pp. 1-14
Author(s):  
N. Boisa ◽  
T. J. K. Ideriah ◽  
C. S. Okehie
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Petroleum Hydrocarbons ◽  
Total Petroleum Hydrocarbons ◽  
Crude Oils ◽  
Low Molecular Weight ◽  
Polycyclic Aromatic ◽  
Pahs Concentration

Aim: To evaluate the concentrations of Polycyclic Aromatic Hydrocarbons and Total Petroleum Hydrocarbons in some Nigerian crude oils. Study Design: Field and Laboratory-Experimental Design were used in this study. Place and Duration of Study: Crude oil samples were obtained from three locations (designated as Location 1, Location 2, and Location 3) in the Niger Delta, Nigeria. Methodology: The samples were subjected to liquid-liquid extraction using dichloromethane and analysed using GC-FID. Results: The results of the analyses of the crude oils gave polycyclic aromatic hydrocarbons (PAHs) concentrations of 2.6089 x 104 ppm representing 60.06% and total petroleum hydrocarbon (TPH) concentration of 4.3201 x 104 ppm at Location 1, PAHs concentration of 4.764 x 103 ppm (62.8%) and TPH recording a concentration of 7.583x 103 ppm at Location 2, while Location 3 had PAHs concentration of 9.93 x 102 ppm (30.66%) and TPH concentration of 3.239 x 103 ppm. The total concentrations of the high molecular weight PAHs were lower than those of the low molecular weight PAHs in the samples. Also the concentrations of the individual PAHs were higher in the low molecular weight PAHs. The mean PAHs concentrations of 2707.6 ppm (location 1), 551.5 ppm (location 2) and 90.7 ppm (location 3) are different. Conclusion: The observed  results show that all the sixteen polycyclic aromatic hydrocarbons listed as priority pollutants are present in the three crude oil samples with higher concentrations in the light crude oils than in the heavy crude oil and a strong correlation with the total petroleum hydrocarbon concentration. It was also observed that though the ratios of the low molecular weight PAHs to high molecular weight PAHs of the crude oils indicate petrogenic, the unique diagnostic ratios suggest pyrogenic input. There is therefore the need to develop a method of PAHs removal from PAHs contaminated water based on locally available and cheap materials.

scholarly journals Toxicity and Risks Assessment of Polycyclic Aromatic Hydrocarbons in River Bed Sediments of an Artisanal Crude Oil Refining Area in the Niger Delta, Nigeria

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3295
Author(s):  
Ibigoni C. Howard ◽  
Kingsley E. Okpara ◽  
Kuaanan Techato
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Niger Delta ◽  
Oil Refining ◽  
Diagnostic Ratios ◽  
Bed Sediments ◽  
River Bed ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants that possess serious risks to human health and the environment. Forty riverbed sediments samples were collected in mangrove river bed sediments where artisanal refining of crude oil takes place in the Niger Delta of Nigeria. The concentration, occurrence, distribution, toxicity and health risk of sixteen priority PAHs (16PAHs) were analysed in the samples. Apart from Nap, Acy, BkF, InP and DbE, all the other PAHs were present in all the sampled points of the studied area with BbF and BaA recording the highest mean values. The range and mean of the total PAHs (∑16PAHs) of this study are 23.461–89.886 mg/kg and 42.607 ± 14.30 mg/kg dry weight (dw), which is classified as heavily contaminated when compared to the European classification of PAHs pollution in soil (>1.0 mg/kg). The range of the effect range factors used to assess the risk of PAHs in an ecosystem (Effect rang-low (ER-L) and Effect range-median ER-M) of this study is from 0.953 to 8.80 mg/kg. PAHs below ER-L (4.0 mg/kg) indicate no toxic effect, but values above ER-M (44.79 mg/kg) indicate toxic effects to the sediments, its resources and, ultimately, the public that consumes the resources thereof; hence, the study area falls within the contaminated category. The occurrence of the high molecular weight (HMW) PAHs (73.4%) supersedes those of the lower molecular weight (LMW) PAHs (26.6%). The diagnostic ratios and principal component analysis suggest that the main contributors of PAHS into the sediments are the combustion of biomass, fossil fuel (crude oil) and pyrogenic sources. The toxic equivalent quotient (TEQ) and mutagenic equivalent quotient (MEQ) of PAHs ranged from 2.96 to 23.26 mgTEQ/kg dw and 4.47 to 23.52 mgMEQ/kg dw, and the total mean toxic equivalency quotient (∑TEQ) (15.12 ± 8.4 mg/kg) is also greater than the safe level of 0.6 mg/kg, which indicates high toxicity potency. The mean incremental lifetime cancer risks (ILCRs) of human exposure to PAHs shows that both adults TotalILCR adults (6.15 × 10−5) and children TotalILCR children (2.48 × 10−4) can be affected by dermal contact rather than ingestion and inhalation. Based on these findings, the appropriate regulatory bodies and other organs of government in the region should enforce outright stoppage of the activities of these illegal artisans who do not have control mechanisms for loss control at the site and carry out appropriate clean-up of the area.

scholarly journals Polycyclic Aromatic Hydrocarbons in Indoor Dust Collected during the COVID-19 Pandemic Lockdown in Saudi Arabia: Status, Sources and Human Health Risks

2021 ◽  
Vol 18 (5) ◽  
pp. 2743
Author(s):  
Sultan Hassan Alamri ◽  
Nadeem Ali ◽  
Hussain Mohammed Salem Ali Albar ◽  
Muhammad Imtiaz Rashid ◽  
Nisreen Rajeh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Saudi Arabia ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Human Health ◽  
Aromatic Hydrocarbons ◽  
Indoor Environment ◽  
Indoor Dust ◽  
Environment Quality ◽  
Indoor Environment Quality ◽  
Polycyclic Aromatic

To control the spread of coronavirus disease (COVID-19), Saudi Arabia’s government imposed a strict lockdown during March–July 2020. As a result, the public was confined to indoors, and most of their daily activities were happening in their indoor places, which might have resulted in lower indoor environment quality. Polycyclic aromatic hydrocarbons (PAHs) were analyzed in household dust (n = 40) collected from different residential districts of Jeddah, Saudi Arabia, during the lockdown period. PAHs’ levels were two folds higher than the previously reported PAHs in indoor dust from this region. We detected low molecular weight (LMW) with two to four aromatic ring PAHs in all the samples with a significant contribution from Phenanthrene (Phe), present at an average concentration of 1590 ng/g of dust. Although high molecular weight (HMW) (5–6 aromatic ring) PAHs were detected at lower concentrations than LMW PAHs, however, they contributed >90% in the carcinogenic index of PAHs. The estimated daily intake (EDI) of specific PAHs was above the reference dose (RfD) for young children in high-end exposure and the calculated Incremental Lifetime Cancer Risk (ILCR) was >1.00 × 10−4 for both Saudi adults and young children. The study highlighted that indoor pollution has increased significantly during lockdown due to the increased indoor activities and inversely affect human health. This study also warrants to conduct more studies involving different chemicals to understand the indoor environment quality during strict lockdown conditions.

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