Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/120426
Author(s): Ribeiro H.
de Sousa T.
Santos J.P.
Sousa A.G.G.
Teixeira C.
Monteiro M.R.
Salgado P.
Mucha A.P.
Almeida C.M.R.
Torgo L.
Magalhães C.
Title: Potential of dissimilatory nitrate reduction pathways in polycyclic aromatic hydrocarbon degradation
Publisher: Elsevier
Issue Date: 2018
Abstract: This study investigates the potential of an indigenous estuarine microbial consortium to degrade two polycyclic aromatic hydrocarbons (PAHs), naphthalene and fluoranthene, under nitrate-reducing conditions. Two physicochemically diverse sediment samples from the Lima Estuary (Portugal) were spiked individually with 25 mg L−1 of each PAH in laboratory designed microcosms. Sediments without PAHs and autoclaved sediments spiked with PAHs were run in parallel. Destructive sampling at the beginning and after 3, 6, 12, 30 and 63 weeks incubation was performed. Naphthalene and fluoranthene levels decreased over time with distinct degradation dynamics varying with sediment type. Next-generation sequencing (NGS) of 16 S rRNA gene amplicons revealed that the sediment type and incubation time were the main drivers influencing the microbial community structure rather than the impact of PAH amendments. Predicted microbial functional analyses revealed clear shifts and interrelationships between genes involved in anaerobic and aerobic degradation of PAHs and in the dissimilatory nitrate-reducing pathways (denitrification and dissimilatory nitrate reduction to ammonium - DNRA). These findings reinforced by clear biogeochemical denitrification signals (NO3 − consumption, and NH4 + increased during the incubation period), suggest that naphthalene and fluoranthene degradation may be coupled with denitrification and DNRA metabolism. The results of this study contribute to the understanding of the dissimilatory nitrate-reducing pathways and help uncover their involvement in degradation of PAHs, which will be crucial for directing remediation strategies of PAH-contaminated anoxic sediments. © 2018 Elsevier
Subject: Anoxic sediments
Aromatization
Denitrification
Genes
Hydrocarbons
Naphthalene
Nitrates
RNA
Degradation dynamics
Dissimilatory nitrate reduction
Fluoranthene
Microbial community structures
Next-generation sequencing
Nitrate-reducing conditions
Polycyclic aromatic hydrocarbons (PAHS)
Remediation strategies
Polycyclic aromatic hydrocarbons
ammonia
fluoranthene
methane
naphthalene
nitrate
nitrogen
organic matter
polycyclic aromatic hydrocarbon
ribosome RNA
ammonium derivative
nitric acid derivative
polycyclic aromatic hydrocarbon
ammonium
biodegradation
community structure
degradation
denitrification
estuarine dynamics
fluoranthene
metabolism
microbial activity
nitrate
PAH
reduction
amplicon
Article
biodegradation
community structure
controlled study
denitrification
incubation time
metabolism
microbial community
microbial consortium
microcosm
next generation sequencing
reduction (chemistry)
sediment
bioremediation
chemistry
denitrification
estuary
Portugal
Limia Estuary
Portugal
Viana do Castelo [Portugal]
Ammonium Compounds
Biodegradation, Environmental
Denitrification
Estuaries
Geologic Sediments
Microbial Consortia
Nitrates
Polycyclic Aromatic Hydrocarbons
Portugal
URI: https://hdl.handle.net/10216/120426
Source: Chemosphere, vol. 199, p. 54-67
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:CIIMAR - Artigo em Revista Científica Internacional

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