Substrate interactions during the biodegradation of benzene, toluene and phenol mixtures

Hamed, Tarık Abu; Bayraktar, Emine; Mehmetoğlu, Tanju; Mehmetoǧlu, Ülkü

doi:10.1016/s0032-9592(02)00293-5

Cited by 46 publications

(19 citation statements)

References 30 publications

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“…Cultures in the present study were able to repopulate when TCE-stressed cells were grown under suitable growth conditions and in the absence of stressor. This response contrasts with previous toxicity studies, in which stressors were present during growth curve experiments, possibly requiring significant energy for cellular repair, and stressed samples leveled off at lower concentrations than unstressed samples [7,9,22].…”

Section: Discussioncontrasting

confidence: 97%

“…The toxic effects of volatile organic contaminants to bacteria are often measured in terms of growth inhibition [7,9,22]. Kim et al [7] reported growth inhibition in several Pseudomonas species at benzene concentrations below saturation, and Wackett and Housekeeper [9] reported TCE toxicity to Pseudomonas putida F1 (P. putida F1) when TCE was provided in the head space as vapor phase.…”

Section: Introductionmentioning

confidence: 99%

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Kinetics of trichloroethylene and toluene toxicity to Pseudomonas putida F1

Singh

Olson

2009

Enviro Toxic and Chemistry

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The goal of the present study was to elucidate the distribution of viable bacteria in chemical gradients and to evaluate the toxic effect of high concentrations of contaminants on contaminant-degrading bacteria under prolonged exposure. Accumulations of viable Pseudomonas putida F1 (P. putida F1) cells were observed surrounding trichloroethylene (TCE)-containing plugs. Results from this work indicate that P. putida F1 immediately adjacent to a TCE source become nonviable, whereas cells accumulating farther away use chemotaxis to migrate toward regions with optimal chemical concentrations in the form of concentrated bacterial bands. A method was developed to test the toxicity of model contaminant stressors, TCE and toluene, to P. putida F1; data obtained from toxicity experiments were fit to linear and exponential bacterial viability-decay models. Toxicity of TCE to P. putida F1 was best described with an exponential viability-decay model, with a viability-decay constant k(TCE) = 0.025 h(-4.95) (r(2) = 0.965). Toluene toxicity showed a marginally better fit to the linear viability-decay model (r(2) = 0.976), with a viability-decay constant k(toluene) = 0.208 h(-1). Best-fit model parameters obtained for both TCE and toluene were used to predict bacterial viability in toxicity experiments with higher contaminant concentrations and matched well with experimental data. Results from the present study can be used to predict bacterial accumulation and viability near nonaqueous-phase liquid (NAPL) sources in groundwater and may be helpful in designing bioremediation strategies for sites contaminated with residual NAPLs.

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Section: Discussioncontrasting

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Kinetics of trichloroethylene and toluene toxicity to Pseudomonas putida F1

Singh

Olson

2009

Enviro Toxic and Chemistry

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“…Shuttleworth and Cerniglia (1996) observed that degradation of phenanthrene by Acidovorax delafieldii and Sphingomonas paucimobilis was inhibited in the presence of naphthalene. In contrast, it has been observed enhanced degradation of benzene and p-xylene in the presence of toluene by Pseudomonas strain (Alvarez and Vogel, 1991) and toluene in the presence of phenol by Pseudomonas putida F1 (Hamed et al, 2003). This phenomenon, which results in the sequential utilization of the carbon sources is called catabolite repression, a complex regulatory mechanism that allows bacteria to preferentially use a particular carbon source over a mixture of several other assimilable, but less preferred, substrates (Müller et al, 1996;Stülke and Hillen, 1999;Morales et al, 2004).…”

Section: Introductionmentioning

confidence: 96%

Cellular fatty acid patterns inPseudomonas sp. CF600 during catechol and phenol degradation in media supplemented with glucose as an additional carbon source

2006

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Fatty acid composition in Pseudomonas sp. CF600 during degradation of catechol and phenol individually and their mixture was investigated. Moreover, the influence of glucose as an additional, easily degradable carbon source on fatty acid profiling in bacteria grown on these aromatic substrates was studied. Both catechol and phenol treatments caused in bacterial cells crucial changes in the distribution of tested groups of fatty acids. The major changes included the increase of fatty acid saturation, decrease in the percentage of cyclopropane fatty acid 17:0 cy and the appearance of branched and hydroxy fatty acids. Under catechol, phenol and their mixture exposure saturated/unsaturated ratio showed the value 6.5, 5.68 and 6.38 whereas in control cells this ratio reached the value 3.05. As a response to aromatic compounds bacteria formed fatty acids that were not detected in control cells growing on glucose. It has been demonstrated that the supplementation of cultured media containing single aromatic substrates or/and their mixture with glucose resulted in changes in degradation rates of catechol and phenol. It seemed that glucose influenced some metabolic pathways responsible for the assimilation of aromatic compounds. The incubation of cells in the presence of aromatic compounds and glucose rapidly led to alterations of whole-cell derived fatty acid composition. The most important changes were associated with saturation level of fatty acids and cyclopropane fatty acid contents.

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“…As effective as these TPPBs have been, they do have several limitations, as noted above, which restrict operation to the use of pure strains of organisms. Pure cultures consisting of single strains of microorganisms have shown to be effective in the degradation of phenol (Bandyopadhyay et al 1998;Beshay et al 2002;Hamed et al 2003;Seker et al 1997;Vrionis et al 2002), however, it has also been shown that microbial consortia can offer improved performance (Ambujom 2001;Guieysse et al 2001b). The benefit of using a robust microbial consortium is often due to its capability of degrading a variety of toxic substrates without the accumulation of toxic intermediates (Acuna-Arguelles et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Enhanced biodegradation of phenol by a microbial consortium in a solid?liquid two phase partitioning bioreactor

2005

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Two phase partitioning bioreactors (TPPBs) operate by partitioning toxic substrates to or from an aqueous, cell-containing phase by means of second immiscible phase. Uptake of toxic substrates by the second phase effectively reduces their concentration within the aqueous phase to sub-inhibitory levels, and transfer of molecules between the phases to maintain equilibrium results in the continual feeding of substrate based on the metabolic demand of the microorganisms. Conventionally, a single pure species of microorganism, and a pure organic solvent, have been used in TPPBs. The present work has demonstrated the benefits of using a mixed microbial population for the degradation of phenol in a TPPB that uses solid polymer beads (comprised of ethylene vinyl acetate, or EVA) as the second phase. Polymer modification via an increase in vinyl acetate concentration was also shown to increase phenol uptake. Microbial consortia were isolated from three biological sources and, based on an evaluation of their kinetic performance, a superior consortium was chosen that offered improved degradation when compared to a pure strain of Pseudomonas putida ATCC 11172. The new microbial consortium used within a TPPB was capable of degrading high concentrations of phenol (approximately 2000 mg l(-1)), with decreased lag time (10 h) and increased specific rate of phenol degradation (0.71 g phenol g(1) cell h). Investigation of the four-member consortium showed that it consisted of two Pseudomonas sp., and two Acinetobacter sp., and tests conducted upon the individual isolates, as well as paired organisms, confirmed the synergistic benefit of their existence within the consortium. The enhanced effects of the use of a microbial consortium now offer improved degradation of phenol, and open the possibility of the degradation of multiple toxic substrates via a polymer-mediated TPPB system.

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Substrate interactions during the biodegradation of benzene, toluene and phenol mixtures

Cited by 46 publications

References 30 publications

Kinetics of trichloroethylene and toluene toxicity to Pseudomonas putida F1

Kinetics of trichloroethylene and toluene toxicity to Pseudomonas putida F1

Cellular fatty acid patterns inPseudomonas sp. CF600 during catechol and phenol degradation in media supplemented with glucose as an additional carbon source

Enhanced biodegradation of phenol by a microbial consortium in a solid?liquid two phase partitioning bioreactor

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