Anaerobic Benzene Biodegradation: A Microcosm Survey

Nales, Marit; Butler, Barbara J.; Edwards, Elizabeth A.

doi:10.1080/10889869891214268

Cited by 57 publications

(64 citation statements)

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“…Its relatively high water solubility and known toxicity combined with apparent chemical and biological stability in situ [reviewed by Johnson et al, 2003] make it a priority pollutant despite its relatively low proportion in many petroleum contaminants. The occurrence and rate of biodegradation appears to be more site-specific for benzene than other BTEX components and is subject to inhibition by those co-contaminants [Johnson et al, 2003;Nales et al, 1998]; degradation is usually slow, incomplete and subject to long lag times .…”

Section: Benzenementioning

confidence: 99%

Anaerobic Biodegradation of Aromatic Hydrocarbons: Pathways and Prospects

Foght¹

2008

Microb Physiol

274

151

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Aromatic hydrocarbons contaminate many environments worldwide, and their removal often relies on microbial bioremediation. Whereas aerobic biodegradation has been well studied for decades, anaerobic hydrocarbon biodegradation is a nascent field undergoing rapid shifts in concept and scope. This review presents known metabolic pathways used by microbes to degrade aromatic hydrocarbons using various terminal electron acceptors; an outline of the few catabolic genes and enzymes currently characterized; and speculation about current and potential applications for anaerobic degradation of aromatic hydrocarbons.

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Section: Benzenementioning

confidence: 99%

Anaerobic Biodegradation of Aromatic Hydrocarbons: Pathways and Prospects

Foght¹

2008

Microb Physiol

274

151

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“…Methanogenic and sulfate-reducing enrichment cultures were derived from microcosms originally prepared with soil and groundwater from a gasoline-contaminated site (42). A nitrate-reducing enrichment culture was derived from microcosms prepared with soil and groundwater from a pristine freshwater swamp (6).…”

Section: Enrichment Culturesmentioning

confidence: 99%

“…For example, biodegradation of benzene under aerobic conditions involves complete mineralization to carbon dioxide (18). Biodegradation of benzene also occurs under anaerobic conditions through various terminal-electron-accepting processes, such as methanogenic (22,30), nitrate-reducing (6,10,42), iron-reducing (30,42), and sulfate-reducing (30,34,42) conditions, although details of the biochemical pathways are still unknown. Anaerobic biodegradation is of particular significance, since BTEX-contaminated groundwater is often anaerobic (2,32) or quickly becomes anaerobic as oxygen is depleted in early stages of biodegradation.…”

mentioning

confidence: 99%

Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

Mancini

Ulrich²,

Lacrampe-Couloume

et al. 2003

Appl Environ Microbiol

Self Cite

162

143

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Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors () for carbon (range of ؊1.9 to ؊3.6‰) and hydrogen (range of ؊29 to ؊79‰) fractionation were observed during biodegradation of benzene under nitratereducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially, C-H bond breakage in the initial step of the anaerobic benzene biodegradation pathway may account for the large fractionation observed compared to that in aerobic benzene biodegradation. Despite some differences in reported enrichment factors between cultures with different terminal-electron-accepting processes, carbon and hydrogen isotope analysis has the potential to provide direct evidence of anaerobic biodegradation of benzene in the field.

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“…Benzene biodegrades anaerobically much less readily than other monoaromatic compounds due to the absence of a substituent on the aromatic ring. Nevertheless, the past 2 decades of research have shown that benzene can be metabolized under nitrate-reducing (3,4), sulfate-reducing (5-7), iron-reducing (8)(9)(10), and methanogenic (11,12) conditions. Despite the interest in this process, the benzene-activating mechanism has remained elusive.…”

mentioning

confidence: 99%

Metatranscriptome of an Anaerobic Benzene-Degrading, Nitrate-Reducing Enrichment Culture Reveals Involvement of Carboxylation in Benzene Ring Activation

Luo

Gitiafroz

Devine

et al. 2014

Appl Environ Microbiol

Self Cite

107

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The enzymes involved in the initial steps of anaerobic benzene catabolism are not known. To try to elucidate this critical step, a metatranscriptomic analysis was conducted to compare the genes transcribed during the metabolism of benzene and benzoate by an anaerobic benzene-degrading, nitrate-reducing enrichment culture. RNA was extracted from the mixed culture and sequenced without prior mRNA enrichment, allowing simultaneous examination of the active community composition and the differential gene expression between the two treatments. Ribosomal and mRNA sequences attributed to a member of the family Peptococcaceae from the order Clostridiales were essentially only detected in the benzene-amended culture samples, implicating this group in the initial catabolism of benzene. Genes similar to each of two subunits of a proposed benzene-carboxylating enzyme were transcribed when the culture was amended with benzene. Anaerobic benzoate degradation genes from strict anaerobes were transcribed only when the culture was amended with benzene. Genes for other benzoate catabolic enzymes and for nitrate respiration were transcribed in both samples, with those attributed to an Azoarcus species being most abundant. These findings indicate that the mineralization of benzene starts with its activation by a strict anaerobe belonging to the Peptococcaceae, involving a carboxylation step to form benzoate. These data confirm the previously hypothesized syntrophic association between a benzene-degrading Peptococcaceae strain and a benzoate-degrading denitrifying Azoarcus strain for the complete catabolism of benzene with nitrate as the terminal electron acceptor.

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Anaerobic Benzene Biodegradation: A Microcosm Survey

Cited by 57 publications

References 0 publications

Anaerobic Biodegradation of Aromatic Hydrocarbons: Pathways and Prospects

Anaerobic Biodegradation of Aromatic Hydrocarbons: Pathways and Prospects

Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

Metatranscriptome of an Anaerobic Benzene-Degrading, Nitrate-Reducing Enrichment Culture Reveals Involvement of Carboxylation in Benzene Ring Activation

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