THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBONS ON THE DEGRADATION OF BENZO[a]PYRENE BY MYCOBACTERIUM SP. STRAIN RJGII-135

McLellan, Sandra L.; Warshawsky, David; Shann, Jodi R.

doi:10.1897/1551-5028(2002)021<0253:teopah>2.0.co;2

Cited by 18 publications

(30 citation statements)

References 32 publications

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“…Thus, depending on the strains, transformation products from one PAH may affect the removal of other PAHs (295,112). Overall, induction effects in complex mixtures may be as important as diauxic effects (49,304,305,418).…”

Section: Aerobic Pah Metabolismmentioning

confidence: 99%

“…Overall, the broad PAH-degrading capabilities in many strains may be attributed to relaxed initial enzyme specificity for PAHs (low and high molecular weight and methyl substituted), the presence of multiple oxygenases, and the presence of multiple metabolic pathways or multiple genes for isofunctional pathways (83,112,160,249,220,330,396,399,418,437,519,520,532,641,677). Finally, the presence of both alkane and aromatic compound-degrading genes within single strains appears to be common (120,301,576,578,641,662).…”

Section: Aerobic Pah Metabolismmentioning

confidence: 99%

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Recent Advances in Petroleum Microbiology

Hamme¹,

Singh

Ward

2003

Microbiol Mol Biol Rev

1,193

640

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Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (<60 s) are being used effectively. Microbes are being injected into partially spent petroleum reservoirs to enhance oil recovery. However, these microbial processes have not exhibited consistent and effective performance, primarily because of our inability to control conditions in the subsurface environment. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. There is interest in replacing physical oil desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H2S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments

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Section: Aerobic Pah Metabolismmentioning

confidence: 99%

Section: Aerobic Pah Metabolismmentioning

confidence: 99%

Recent Advances in Petroleum Microbiology

Hamme¹,

Singh

Ward

2003

Microbiol Mol Biol Rev

1,193

640

View full text Add to dashboard Cite

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“…The specific affinity (calculated as maximum degradation rate [V max ]/Michaelis-Menten half-saturation constant [K m ]) of LB501T cells for aqueous anthracene was found to be higher than the specific affinities of other cultures reported elsewhere (41). A diverse range of K m values for PAH degradation have been obtained with pure cultures (1,12,18,27,36) and mixed cultures (19). Wick et al have proposed the presence of a high-affinity uptake system in LB501T (41), which would account for the facile degradation of aqueous-phase PAHs occurring at extremely low concentrations in the environment.…”

mentioning

confidence: 99%

“…In this study, we examined the mechanism of uptake of aqueous-phase phenanthrene by Mycobacterium sp. strain RJGII-135, capable of degrading both low-and high-molecular-weight PAHs (17,27,33). The cell suspensions were prepared from cultures grown on either phenanthrene or acetate.…”

mentioning

confidence: 99%

Saturable, Energy-Dependent Uptake of Phenanthrene in Aqueous Phase by Mycobacterium sp. Strain RJGII-135

Miyata

Iwahori

Foght

et al. 2004

Appl Environ Microbiol

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The mechanism of uptake of phenanthrene by Mycobacterium sp. strain RJGII-135, a polycyclic hydrocarbondegrading bacterium, was examined with cultures grown on phenanthrene (induced for phenanthrene metabolism) and acetate (uninduced). Washed cells were suspended in aqueous solutions of [9-14 C]phenanthrene, and then the cells were collected by filtration. Low-level steady-state 14 C concentrations in uninduced cells were achieved within the first 15 s of incubation. This immediate uptake did not show saturation kinetics and was not susceptible to inhibitors of active transport, cyanide and carbonyl cyanide m-chlorophenylhydrazone. These results indicated that phenanthrene enters rapidly into the cells by passive diffusion. However, induced cells showed cumulative uptake over several minutes. The initial uptake rates followed saturation kinetics, with an apparent affinity constant (K t ) of 26 ؎ 3 nM (mean ؎ standard deviation). Uptake of phenanthrene by induced cells was strongly inhibited by the inhibitors. Analysis of cell-associated 14 C-labeled compounds revealed that the concurrent metabolism during uptake was rapid and was not saturated at the substrate concentrations tested, suggesting that the saturable uptake observed reflects membrane transport rather than intracellular metabolism. These results were consistent with the presence of a saturable, energy-dependent mechanism for transport of phenanthrene in induced cells. Moreover, the kinetic data for the cumulative uptake suggested that phenanthrene is specifically bound by induced cells, based on its saturation with an apparent dissociation constant (K d ) of 41 ؎ 21 nM (mean ؎ standard deviation). Given the low values of K t and K d , Mycobacterium sp. strain RJGII-135 may use a high-affinity transport system(s) to take up phenanthrene from the aqueous phase.Many polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, fluoranthene, anthracene, pyrene, benz [a]anthracene, and benzo [a]pyrene are known to be utilized as sole carbon and energy sources, or are degraded cometabolically, by a diverse group of bacteria (11,22). Biodegradation is a significant tool for the removal of these contaminants from environments, but their low bioavailability, especially for high-molecular-weight PAHs, has often been observed in the environment and bioremediation systems (2,22). Due to their extremely hydrophobic nature, PAHs partition readily into solid and liquid organic phases and exist in aqueous phase only at limited concentrations. This makes uptake of PAHs by bacterial cells difficult. In bacterial cultures where only the compounds dissolved in aqueous solution are utilized, mass transfer or the rate of desorption controls the rates of degradation and culture growth (2).Nevertheless, several studies have reported that degradation kinetics for the PAHs vary among different bacteria and that some bacteria apparently show rapid degradation of such PAHs with concomitant growth (16,18,37). Thus, some bacteria seem to have adapted to the low availa...

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“…strain LB501T do not produce biosurfactant but still have a strong ability to degrade low concentrations of aqueous-phase anthracene. The specifi c affi nity of strain LB501T cells for aqueous anthracene was found to be higher than the specifi c affi nities of other cultures reported elsewhere [91][92][93]. Wick et al [91] proposed the presence of a high-affi nity uptake system in strain LB501T to account for these observations.…”

Section: Transport Of Pahs Into the Cellmentioning

confidence: 72%

Bacterial metabolism of polycyclic aromatic hydrocarbons: strategies for bioremediation

et al. 2008

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Polycyclic aromatic hydrocarbons (PAHs) are compounds of intense public concern due to their persistence in the environment and potentially deleterious effects on human, environmental and ecological health. The clean up of such contaminants using invasive technologies has proven to be expensive and more importantly often damaging to the natural resource properties of the soil, sediment or aquifer. Bioremediation, which exploits the metabolic potential of microbes for the clean-up of recalcitrant xenobiotic compounds, has come up as a promising alternative. Several approaches such as improvement in PAH solubilization and entry into the cell, pathway and enzyme engineering and control of enzyme expression etc. are in development but far from complete. Successful application of the microorganisms for the bioremediation of PAH-contaminated sites therefore requires a deeper understanding of the physiology, biochemistry and molecular genetics of potential catabolic pathways. In this review, we briefl y summarize important strategies adopted for PAH bioremediation and discuss the potential for their improvement.

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THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBONS ON THE DEGRADATION OF BENZO[a]PYRENE BY MYCOBACTERIUM SP. STRAIN RJGII-135

Cited by 18 publications

References 32 publications

Recent Advances in Petroleum Microbiology

Recent Advances in Petroleum Microbiology

Saturable, Energy-Dependent Uptake of Phenanthrene in Aqueous Phase by Mycobacterium sp. Strain RJGII-135

Bacterial metabolism of polycyclic aromatic hydrocarbons: strategies for bioremediation

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