Initial reactions in the anaerobic oxidation of toluene and m-xylene by denitrifying bacteria

Seyfried, Birgit K.; Glod, Guy; Schocher, R; Tschech, Andreas; Zeyer, Josef

doi:10.1128/aem.60.11.4047-4052.1994

Cited by 65 publications

(34 citation statements)

References 22 publications

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“…This may be concluded from the observations that (i) p-xylene did not support growth in subcultures; (ii) only a minor part of p-xylene was consumed ᮊ 1999 Blackwell Science Ltd, Environmental Microbiology, 1, [145][146][147][148][149][150][151][152][153][154][155][156][157] (Brosius et al, 1981). from the oil; and (iii) pure cultures of denitrifiers or sulphate-reducing bacteria also formed p-methylbenzoate as a dead end-product from p-xylene (Seyfried et al, 1994;Biegert and Fuchs, 1995;Rabus and Widdel, 1995b;Beller et al, 1996). Similarly, another p-disubstituted alkylbenzene, 1,2,4-trimethylbenzene, may have been oxidized co-metabolically with growth-supporting alkylbenzenes.…”

Section: Discussionmentioning

confidence: 99%

Anaerobic utilization of alkylbenzenes and n‐alkanes from crude oil in an enrichment culture of denitrifying bacteria affiliating with the β‐subclass of Proteobacteria

Rabus¹,

Wilkes²,

Schramm³

et al. 1999

Environmental Microbiology

105

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Denitrifying bacteria were enriched from freshwater sediment with added nitrate as electron acceptor and crude oil as the only source of organic substrates. The enrichment cultures were used as laboratory model systems for studying the degradative potential of denitrifying bacteria with respect to crude oil constituents, and the phylogenetic affiliation of denitrifiers that are selectively enriched with crude oil. The enrichment culture exhibited two distinct growth phases. During the first phase, bacteria grew homogeneously in the aqueous phase, while various C1-C3 alkylbenzenes, but no alkanes, were utilized from the crude oil. During the second phase, bacteria also grew that formed aggregates, adhered to the crude oil layer and emulsified the oil, while utilization of n-alkanes (C5 to C12) from the crude oil was observed. During growth, several alkylbenzoates accumulated in the aqueous phase, which were presumably formed from alkylbenzenes. Application of a newly designed, fluorescently labelled 16S rRNA-targeted oligonucleotide probe specific for the Azoarcus/Thauera group within the beta-subclass of Proteobacteria revealed that the majority of the enriched denitrifiers affiliated with this phylogenetic group.

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Section: Discussionmentioning

confidence: 99%

Anaerobic utilization of alkylbenzenes and n‐alkanes from crude oil in an enrichment culture of denitrifying bacteria affiliating with the β‐subclass of Proteobacteria

Rabus¹,

Wilkes²,

Schramm³

et al. 1999

Environmental Microbiology

105

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“…Among aromatic hydrocarbons, only toluene was shown before to serve as growth substrate for isolated strains of sulfate-reducing bacteria (2,32). Anaerobic growth of pure cultures on m-xylene has been shown with denitrifying bacteria (9,15,20,28,36). However, to our knowledge, no strain of any type of anaerobic bacterium that grows on o-xylene or p-xylene has been isolated to date.…”

mentioning

confidence: 99%

Anaerobic Oxidation of o -Xylene, m -Xylene, and Homologous Alkylbenzenes by New Types of Sulfate-Reducing Bacteria

Harms

Zengler

Rabus

et al. 1999

Appl Environ Microbiol

188

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Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the δ subclass of the classProteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum andDesulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, ando-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene,m-isoproyltoluene, benzoate, andm-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.

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“…Some or all of these intermediates were also implicated in the biodegradation of toluene under other anaerobic conditions, such as denitrifying and iron reducing conditions. 23, 30 Under aerobic conditions, benzyl alcohol, benzaldehyde, benzoate, and catechol were reported to be possible intermediates in the metabolism of toluene by Pseudomonas putida (arvilla) mt-2.33.36 Based on these observations, the foregoing aromatic compounds were selected for the carbon source tests. Phenyl acetate and three aromatic amino acids, tryptophan, tyrosine and phenylalanine, were also included in the tests.…”

Section: Other Aromatic Hydrocarbons As Carbon Sourcesmentioning

confidence: 99%

Thermophilic biodegradation of BTEX by two Thermus Species

Chen

Taylor

1995

Biotech & Bioengineering

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Two thermophilic bacteria, Thermus aquaticus ATCC 25104 and Thermus species ATCC 27978, were investigated for their abilities to degrade BTEX (benzene, toluene, ethylbenzene, and xylenes). Thermus aquaticus and the Thermus sp. were grown in a nominal medium at 70 degrees C and 60 degrees C, respectively, and resting cell suspensions were used to study BTEX biodegradation at the same corresponding temperatures. The degradation of BTEX by these cell suspensions was measured in sealed serum bottles against controls that also displayed significant abiotic removals of BTEX under such high-temperature conditions. For T. aquaticus at a suspension density of only 1.3 x 10(7) cells/mL and an aqueous total BTEX concentration of 2.04 mg/L (0.022 mM), benzene, toluene, ethylbenzene, m-xylene, and an unresolved mixture of o-and p-xylenes were biodegraded by 10, 12, 18, 20, and 20%, respectively, after 45 days of incubation at 70 degrees C. For the Thermus sp. at a suspension density of 1.1 x 10(7) cells/mL and an aqueous total BTEX concentration of 6.98 mg/L (0.079 mM), benzene, toluene, ethylbenzene, m-xylene, and the unresolved mixture of o-and p-xylenes were biodegraded by 40, 35, 32, 33, and 33%, respectively, after 45 days of incubation at 60 degrees C. Raising the BTEX concentrations lowered the extents of biodegradation. The biodegradations of both benzene and toluene were enhanced when T. aquaticus and the Thermus sp. were pregrown on catechol and o-cresol, respectively, as carbon sources. Use of [U-(14)C]benzene and [ring-(14)C]toluene verified that a small fraction of these two compounds was metabolized within 7 days to water-soluble products and CO(2) by these nongrowing cell suspensions. Our investigation also revealed that the nominal medium can be simplified by eliminating the yeast extract and using a higher tryptone concentration (0.2%) without affecting the growth and BTEX degrading activities of these cells. (c) 1995 John Wiley & Sons, Inc.

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Initial reactions in the anaerobic oxidation of toluene and m-xylene by denitrifying bacteria

Cited by 65 publications

References 22 publications

Anaerobic utilization of alkylbenzenes and n‐alkanes from crude oil in an enrichment culture of denitrifying bacteria affiliating with the β‐subclass of Proteobacteria

Anaerobic utilization of alkylbenzenes and n‐alkanes from crude oil in an enrichment culture of denitrifying bacteria affiliating with the β‐subclass of Proteobacteria

Anaerobic Oxidation of o -Xylene, m -Xylene, and Homologous Alkylbenzenes by New Types of Sulfate-Reducing Bacteria

Thermophilic biodegradation of BTEX by two Thermus Species

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