1
|
Lagos S, Perruchon C, Tsikriki A, Gourombinos E, Vasileiadis S, Sotiraki S, Karpouzas DG. Bioaugmentation of animal feces as a mean to mitigate environmental contamination with anthelmintic benzimidazoles. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126439. [PMID: 34174622 DOI: 10.1016/j.jhazmat.2021.126439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
Anthelmintics are used to control infestations of ruminants by gastrointestinal nematodes. The limited metabolism of anthelmintics in animals result in their excretion in feces. These could be piled up in the floor of livestock farms, constituting a point source of environmental contamination, or used as manures in agricultural soils where they persist or move to water bodies. Hence the removal of anthelmintics from feces could mitigate environmental contamination. We hypothesized that a thiabendazole-degrading bacterial consortium would also degrade other benzimidazole anthelmintics like albendazole, fenbendazole, ricobendazole, mebendazole and flubendazole. In liquid culture tests the consortium was more effective in degrading compounds with smaller benzimidazole substituents (thiabendazole, albendazole, ricobendazole), rather than benzimidazoles with bulky substituents (fenbendazole, flubendazole, mebendazole). We then explored the bioaugmentation capacity of the consortium in sheep feces fortified with 5 and 50 mg kg-1 of thiabendazole, albendazole and fenbendazole. Bioaugmentation enhanced the degradation of all compounds and its efficiency was accelerated upon fumigation of feces, in the absence of the indigenous fecal microbial community. The latter contributes to anthelmintics degradation as suggested by the significantly lower DT50 values in fumigated vs non-fumigated, non-bioaugmented feces. Overall, bioaugmentation could be an efficient means to reduce environmental exposure to recalcitrant anthelmintic benzimidazoles.
Collapse
Affiliation(s)
- S Lagos
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece
| | - C Perruchon
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece
| | - A Tsikriki
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece
| | - E Gourombinos
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece
| | - S Vasileiadis
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece
| | - S Sotiraki
- HAO-DEMETER, Institute of Veterinary Research, Thermi 57100, Greece
| | - D G Karpouzas
- University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500 Larissa, Greece.
| |
Collapse
|
2
|
Lu H, Wang W, Li F, Zhu L. Mixed-surfactant-enhanced phytoremediation of PAHs in soil: Bioavailability of PAHs and responses of microbial community structure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 653:658-666. [PMID: 30759591 DOI: 10.1016/j.scitotenv.2018.10.385] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/22/2018] [Accepted: 10/28/2018] [Indexed: 06/09/2023]
Abstract
The present study was conducted to explore the mechanisms of surfactant-enhanced phytoremediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs), focusing on the bioavailability of PAHs and microbial diversity. We investigated the remediation efficiencies of phenanthrene and pyrene after the addition of mixed surfactants (sodium dodecyl benzene sulfonate (SDBS) and Tween 80) of different ratios (1:1, 1:2, and 2:1) at the concentration of 100 mg/kg to soils cultured with ryegrass (Lolium multiflorum L.). The fractions of phenanthrene and pyrene were determined using a sequential extraction method, and the microbial diversity was evaluated using 16S rRNA gene high-throughput sequencing. The results showed that mixed surfactants could enhance the remediation efficiencies of PAHs, and mainly occurred in the initial 21 days. Mixed surfactants at the ratio of 1:1 (HM1) showed the best remediation efficiency in enhancing the dissipation of pyrene in 21 days. Mixed surfactants showed little effects on the removal of phenanthrene. In general, HM1 significantly decreased the bioavailable, bound and residual fractions of pyrene; additionally, higher abundances of PAH-degradation bacteria and degradation-related genes were observed. Pearson correlation analysis among PAH degraders, degradation-related genes and bioavailable fraction of PAHs was performed. Our results indicated that mixed surfactants could promote the transformation of pyrene from the bound and residual fractions to bioavailable fractions and enhance the abundances of PAH degradation bacteria and PAH degradation-related genes, thereby enhancing the degradation of pyrene.
Collapse
Affiliation(s)
- Hainan Lu
- Dept Environm Sci, Zhejiang Univ, Hangzhou 310058, Zhejiang, China; Zhejiang Prov Key Lab Organ Pollut Proc Control, Hangzhou 310058, Zhejiang, China
| | - Wei Wang
- Dept Environm Sci, Zhejiang Univ, Hangzhou 310058, Zhejiang, China; Zhejiang Prov Key Lab Organ Pollut Proc Control, Hangzhou 310058, Zhejiang, China
| | - Feng Li
- Dept Environm Sci & Engn, Xiangtan Univ, Xiangtan 411105, China
| | - Lizhong Zhu
- Dept Environm Sci, Zhejiang Univ, Hangzhou 310058, Zhejiang, China; Zhejiang Prov Key Lab Organ Pollut Proc Control, Hangzhou 310058, Zhejiang, China.
| |
Collapse
|
3
|
Silva EJ, Correa PF, Almeida DG, Luna JM, Rufino RD, Sarubbo LA. Recovery of contaminated marine environments by biosurfactant-enhanced bioremediation. Colloids Surf B Biointerfaces 2018; 172:127-135. [PMID: 30145458 DOI: 10.1016/j.colsurfb.2018.08.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 08/02/2018] [Accepted: 08/16/2018] [Indexed: 01/23/2023]
Abstract
The need to remediate areas contaminated by petroleum products has led to the development of novel technologies for treating such contaminants in a non-conventional manner, that is, without the use of chemical or physical methods. Biosurfactants are amphipathic biomolecules produced by microorganisms that can be used in bioremediation processes in environments contaminated by petroleum products due to their excellent tensioactive properties. The aim of the present study was to produce a biosurfactant from Pseudomonas aeruginosa UCP 0992 cultivated in 0.5% corn steep liquor and 4.0% vegetable oil residue in a 1.2-L bioreactor employing a central composite rotatable design to optimize the cultivation conditions for maximum yield. The best results were achieved with aeration rate of 1.0 vvm and 3.0% inoculum at 225 rpm for 120 h, resulting in a surface tension of 26.5 mN/m and a biosurfactant yield of 26 g/L. Kinetic and static assays were then performed with the biosurfactant for the removal of motor oil adsorbed to sand, with removal rates around 90% and 80%, respectively, after 24 h. Oil degradation experiments with the bacterium and the combination of the bacterium and biosurfactant were also conducted to simulate the bioremediation process in sand and seawater samples (duration: 75 and 30 days, respectively). In both cases, oil degradation rates were higher than 90% in the presence of the biosurfactant and the producing species, indicating the potential of the biomolecule as an adjuvant in petroleum decontamination processes in the marine environment.
Collapse
Affiliation(s)
- Elias J Silva
- Northeast Biotechnology Network (RENORBIO), Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos. Zip Code: 52171900, Recife, Pernambuco, Brazil
| | - Priscilla F Correa
- Catholic University of Pernambuco (UNICAP), Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil
| | - Darne G Almeida
- Catholic University of Pernambuco (UNICAP), Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil; Advanced Institute of Technology and Innovation (IATI), Rua Joaquim de Brito, n.216, Boa Vista, Zip Code: 50070-280, Recife, Pernambuco, Brazil
| | - Juliana M Luna
- Catholic University of Pernambuco (UNICAP), Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil; Advanced Institute of Technology and Innovation (IATI), Rua Joaquim de Brito, n.216, Boa Vista, Zip Code: 50070-280, Recife, Pernambuco, Brazil
| | - Raquel D Rufino
- Catholic University of Pernambuco (UNICAP), Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil; Advanced Institute of Technology and Innovation (IATI), Rua Joaquim de Brito, n.216, Boa Vista, Zip Code: 50070-280, Recife, Pernambuco, Brazil
| | - Leonie A Sarubbo
- Northeast Biotechnology Network (RENORBIO), Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos. Zip Code: 52171900, Recife, Pernambuco, Brazil; Advanced Institute of Technology and Innovation (IATI), Rua Joaquim de Brito, n.216, Boa Vista, Zip Code: 50070-280, Recife, Pernambuco, Brazil.
| |
Collapse
|
4
|
Hu G, Li J, Zeng G. Recent development in the treatment of oily sludge from petroleum industry: a review. JOURNAL OF HAZARDOUS MATERIALS 2013; 261:470-490. [PMID: 23978722 DOI: 10.1016/j.jhazmat.2013.07.069] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/29/2013] [Indexed: 06/02/2023]
Abstract
Oily sludge is one of the most significant solid wastes generated in the petroleum industry. It is a complex emulsion of various petroleum hydrocarbons (PHCs), water, heavy metals, and solid particles. Due to its hazardous nature and increased generation quantities around the world, the effective treatment of oily sludge has attracted widespread attention. In this review, the origin, characteristics, and environmental impacts of oily sludge were introduced. Many methods have been investigated for dealing with PHCs in oily sludge either through oil recovery or sludge disposal, but little attention has been paid to handle its various heavy metals. These methods were discussed by dividing them into oil recovery and sludge disposal approaches. It was recognized that no single specific process can be considered as a panacea since each method is associated with different advantages and limitations. Future efforts should focus on the improvement of current technologies and the combination of oil recovery with sludge disposal in order to comply with both resource reuse recommendations and environmental regulations. The comprehensive examination of oily sludge treatment methods will help researchers and practitioners to have a good understanding of both recent developments and future research directions.
Collapse
Affiliation(s)
- Guangji Hu
- Environmental Engineering Program, University of Northern British Columbia, Prince George, British Columbia, Canada V2N 4Z9
| | | | | |
Collapse
|
5
|
Zhang D, Zhu L, Li F. Influences and mechanisms of surfactants on pyrene biodegradation based on interactions of surfactant with a Klebsiella oxytoca strain. BIORESOURCE TECHNOLOGY 2013; 142:454-61. [PMID: 23751486 DOI: 10.1016/j.biortech.2013.05.077] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/19/2013] [Accepted: 05/20/2013] [Indexed: 05/22/2023]
Abstract
Surfactant-enhanced bioremediation has been proposed as a promising technology for the treatment of organic polluted soils; however its application has been hindered by the controversial influences and mechanisms of surfactants on the biodegradation of hydrophobic organic compounds. To address this problem, effects of five surfactants on the sorption and biodegradation of pyrene by Klebsiella oxytoca PYR-1, as well as their interactions with bacterial cell surface and membrane lipids were investigated. We found that surfactants enhanced or inhibited pyrene biodegradation depending on their effects on the sorption of pyrene onto bacterial cell, which occurred mainly through modifying cell surface hydrophobicity (such as Tween series surfactants) or disrupting bacterial membrane (such as Triton X-100), respectively. A relatively high positive correlation (P<0.0001) was observed between biodegradation promotion (Bs/B0) and enhancement of sorption coefficients (Kd,s(∗)/Kd,0(∗)) for pyrene in the presence of surfactant, indicating that surfactant-induced sorption played the dominant role during pyrene biodegradation.
Collapse
Affiliation(s)
- Dong Zhang
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | | | | |
Collapse
|
6
|
Smith KEC, Rein A, Trapp S, Mayer P, Karlson UG. Dynamic passive dosing for studying the biotransformation of hydrophobic organic chemicals: microbial degradation as an example. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:4852-4860. [PMID: 22458885 DOI: 10.1021/es204050u] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Biotransformation plays a key role in hydrophobic organic compound (HOC) fate, and understanding kinetics as a function of (bio)availability is critical for elucidating persistence, accumulation, and toxicity. Biotransformation mainly occurs in an aqueous environment, posing technical challenges for producing kinetic data because of low HOC solubilities and sorptive losses. To overcome these, a new experimental approach based on passive dosing is presented. This avoids using cosolvent for introducing the HOC substrate, buffers substrate depletion so biotransformation is measured within a narrow and defined dissolved concentration range, and enables high compound turnover even at low concentrations to simplify end point measurement. As a case study, the biodegradation kinetics of two model HOCs by the bacterium Sphingomonas paucimobilis EPA505 were measured at defined dissolved concentrations ranging over 4 orders of magnitude, from 0.017 to 658 μg L(-1) for phenanthrene and from 0.006 to 90.0 μg L(-1) for fluoranthene. Both compounds had similar mineralization fluxes, and these increased by 2 orders of magnitude with increasing dissolved concentrations. First-order mineralization rate constants were also similar for both PAHs, but decreased by around 2 orders of magnitude with increasing dissolved concentrations. Dynamic passive dosing is a useful tool for measuring biotransformation kinetics at realistically low and defined dissolved HOC concentrations.
Collapse
Affiliation(s)
- Kilian E C Smith
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark.
| | | | | | | | | |
Collapse
|
7
|
Agarry SE, Ogunleye OO. Factorial Designs Application to Study Enhanced Bioremediation of Soil Artificially Contaminated with Weathered Bonny Light Crude Oil through Biostimulation and Bioaugmentation Strategy. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/jep.2012.38089] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
8
|
|
9
|
Randall K, Cheng SW, Kotchevar AT. Evaluation of surfactants as solubilizing agents in microsomal metabolism reactions with lipophilic substrates. In Vitro Cell Dev Biol Anim 2011; 47:631-9. [PMID: 21898118 DOI: 10.1007/s11626-011-9449-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 08/19/2011] [Indexed: 10/17/2022]
Abstract
Solubilizing agents are routinely added when investigating the biotransformation of lipophilic substrates using hepatic microsomes. For highly lipophilic compounds, the concentration of solvent or surfactant necessary for dissolution can be detrimental to enzyme activity. This study evaluates the effect of 12 surfactants on microsomal metabolism and the ability of the same surfactants to improve the aqueous solubility of the pentabrominated diphenyl ether BDE-100, a lipophilic environmental contaminant previously found to be recalcitrant to in vitro metabolism. Of the surfactants investigated, Cremophor EL and Tween 80 displayed the best combination of increased BDE-100 solubility and minimal inhibition of microsomal metabolism. However, a comparison of the in vitro metabolism products of BDE-100 in the presence of the two surfactants revealed varying amounts of metabolites depending on the surfactant used.
Collapse
Affiliation(s)
- Kathleen Randall
- Department of Chemistry and Biochemistry, California State University, East Bay, Hayward, CA 94542, USA
| | | | | |
Collapse
|
10
|
Kanaly RA, Harayama S. Advances in the field of high-molecular-weight polycyclic aromatic hydrocarbon biodegradation by bacteria. Microb Biotechnol 2010; 3:136-64. [PMID: 21255317 PMCID: PMC3836582 DOI: 10.1111/j.1751-7915.2009.00130.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 05/22/2009] [Accepted: 05/26/2009] [Indexed: 11/26/2022] Open
Abstract
Interest in understanding prokaryotic biotransformation of high-molecular-weight polycyclic aromatic hydrocarbons (HMW PAHs) has continued to grow and the scientific literature shows that studies in this field are originating from research groups from many different locations throughout the world. In the last 10 years, research in regard to HMW PAH biodegradation by bacteria has been further advanced through the documentation of new isolates that represent diverse bacterial types that have been isolated from different environments and that possess different metabolic capabilities. This has occurred in addition to the continuation of in-depth comprehensive characterizations of previously isolated organisms, such as Mycobacterium vanbaalenii PYR-1. New metabolites derived from prokaryotic biodegradation of four- and five-ring PAHs have been characterized, our knowledge of the enzymes involved in these transformations has been advanced and HMW PAH biodegradation pathways have been further developed, expanded upon and refined. At the same time, investigation of prokaryotic consortia has furthered our understanding of the capabilities of microorganisms functioning as communities during HMW PAH biodegradation.
Collapse
Affiliation(s)
- Robert A Kanaly
- Department of Genome Systems, Faculty of Bionanoscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Kanagawa-ken, Yokohama 236-0027, Japan.
| | | |
Collapse
|
11
|
Biosurfactant's role in bioremediation of NAPL and fermentative production. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 672:222-35. [PMID: 20545286 DOI: 10.1007/978-1-4419-5979-9_17] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Surfactants and biosurfactants are amphipathic molecules with both hydrophilic and hydrophobic moieties that partition preferentially at the interface between fluid phases that have different degrees of polarity and hydrogen bonding which confers excellent detergency, emulsifying, foaming and dispersing traits, making them most versatile process chemicals. One of the major applications of (bio)surfactants is in environmental bioremediation field. Most synthetic organic compounds present in contaminated soils are only weakly soluble or completely insoluble in water, so they exist in the subsurface as separate liquid phase, often referred as a non-aqueous phase liquids (NAPL), which poses as threat to environment. Several studies have revealed the use of surfactants for remediation; however, several factors limit the use of surfactants in environmental remediation, mainly persistence of surfactants or their metabolites and thus potentially pose an environmental concern. Biosurfactants may provide a more cost-effective approach for subsurface remediation when used alone or in combination with synthetic surfactants. There are several advantages of biosurfactants when compared to chemical surfactants, mainly biodegradability, low toxicity, biocompatibility and ability to be synthesized from renewable feedstock. Despite having many commercially attractive properties and clear advantages compared with their synthetic counterparts, biosurfactants have not yet been employed extensively in industry because of their low yields and relatively high production and recovery costs. However, the use of mutants and recombinant hyperproducing microorganisms along with the use of cheaper raw materials and optimal growth and production conditions and more efficient recovery processes, the production of biosurfactant can be made economically feasible. Therefore, future research aiming for high-level production of biosurfactants must be focused towards the development of appropriate combinations of hyperproducing microbial strains, optimized cheaper production media and optimized process conditions, which will lead to economical commercial level biosurfactant production.
Collapse
|
12
|
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are toxic environmental pollutants that are known or suspected carcinogens or mutagens. Bioremediation has been used as a general way to eliminate them from the contaminated sites or aquifers, but their biodegradation is rather limited due to their low bioavailability because of their sparingly soluble nature. Surfactant-mediated biodegradation is a promising alternative. The presence of surfactants can increase the solubility of PAHs and hence potentially increase their bioavailability. However, inconclusive results have been reported on the effects of surfactant on the biodegradation of PAHs. In this work, surfactant-mediated biodegradation of PAHs is reviewed.
Collapse
|
13
|
Kalme S, Parshetti G, Gomare S, Govindwar S. Diesel and Kerosene Degradation by Pseudomonas desmolyticum NCIM 2112 and Nocardia hydrocarbonoxydans NCIM 2386. Curr Microbiol 2008; 56:581-6. [DOI: 10.1007/s00284-008-9128-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Accepted: 06/20/2007] [Indexed: 11/24/2022]
|
14
|
Dimitriou-Christidis P, Autenrieth RL. Kinetics of biodegradation of binary and ternary mixtures of PAHs. Biotechnol Bioeng 2007; 97:788-800. [PMID: 17115447 DOI: 10.1002/bit.21269] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The kinetics of biodegradation of mixtures of polycyclic aromatic hydrocarbons (PAHs) by Sphingomonas paucimobilis strain EPA505 were investigated. The investigation focused on three- and four-ring PAHs, specifically 2-methylphenanthrene, fluoranthene, and pyrene. Uptake rates in aerobic batch suspended cultivations were measured for the individual PAHs and their binary and ternary mixtures. It was observed that kinetics were influenced by the mixture composition and the kinetic properties of the components. A material balance equation containing the Monod model was numerically fitted to uptake data to determine extant kinetic parameters for the individual PAHs. Similarly, equations containing kinetic interaction models derived from enzyme kinetics were fitted to the uptake data obtained from experiments with binary and ternary mixtures. The investigation considered the following interaction types: no-interaction (Monod), pure competitive interaction, noncompetitive or mixed-type interaction, uncompetitive inhibition, and nonspecific interaction based on pure competition (SKIP). Model fit was evaluated based on probabilistic and statistical criteria and inferences were reached about underlying interaction mechanisms based on model fit. Mixture kinetics were most adequately simulated by the pure competitive interaction model with mutual substrate exclusivity. This model is fully predictive, relying only on parameters determined in the sole-PAH experiments. It was shown that for low percent inhibition values and with limited data, pure competitive interaction kinetics may not be evident, resembling no-interaction kinetics. This study is a reasonable starting point for understanding and modeling biodegradation of complex PAH mixtures in engineered and natural systems.
Collapse
Affiliation(s)
- Petros Dimitriou-Christidis
- Department of Civil Engineering, Environmental Engineering Division, Texas A&M University, 3136 TAMU, College Station, Texas 77843-3136, USA
| | | |
Collapse
|
15
|
Dimitriou-Christidis P, Autenrieth RL, McDonald TJ, Desai AM. Measurement of biodegradability parameters for single unsubstituted and methylated polycyclic aromatic hydrocarbons in liquid bacterial suspensions. Biotechnol Bioeng 2007; 97:922-32. [PMID: 17115446 DOI: 10.1002/bit.21268] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Substrate depletion experiments were conducted to characterize aerobic biodegradation of 20 single polycyclic aromatic hydrocarbons (PAHs) by induced Sphingomonas paucimobilis strain EPA505 in liquid suspensions. PAHs consisted of low molecular weight, unsubstituted, and methyl-substituted homologs. A material balance equation containing the Andrews kinetic model, an extension of the Monod model accounting for substrate inhibition, was numerically fitted to batch depletion data to estimate extant kinetic parameters including the maximal specific uptake rates, q(max), the affinity coefficients, K(S), and the substrate inhibition coefficients, K(I). Strain EPA505 degraded all PAHs tested. Applied kinetic models adequately simulated experimental data. A cell proliferation assay involving reduction of the tetrazolium dye WST-1 was used to evaluate the ability of strain EPA505 to utilize individual PAHs as sole energy and carbon sources. Of the 22 PAHs tested, 9 supported bacterial growth. Evaluation of the biokinetic data showed that q(max) correlated highly with transmembrane flux as theoretically estimated by a diffusion model, pointing to transmembrane transport as a potential rate-determining process. The biodegradability data generated in this study is essential for the development of quantitative structure-activity relationships (QSARs) for biodegradability and for modeling biodegradation of simple PAH mixtures.
Collapse
Affiliation(s)
- Petros Dimitriou-Christidis
- Environmental Engineering Division, Department of Civil Engineering, Texas A&M University, 3136 TAMU, College Station, Texas 77843-3136, USA
| | | | | | | |
Collapse
|
16
|
Desai AM, Autenrieth RL, Dimitriou-Christidis P, McDonald TJ. Biodegradation kinetics of select polycyclic aromatic hydrocarbon (PAH) mixtures by Sphingomonas paucimobilis EPA505. Biodegradation 2007; 19:223-33. [PMID: 17534722 DOI: 10.1007/s10532-007-9129-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Accepted: 04/24/2007] [Indexed: 11/24/2022]
Abstract
Many contaminated sites commonly have complex mixtures of polycyclic aromatic hydrocarbons (PAHs) whose individual microbial biodegradation may be altered in mixtures. Biodegradation kinetics for fluorene, naphthalene, 1,5-dimethylnaphthalene and 1-methylfluorene were evaluated in sole substrate, binary and ternary systems using Sphingomonas paucimobilis EPA505. The first order rate constants for fluorene, naphthalene, 1,5-dimethylnaphthalene, and 1-methylfluorene were comparable; yet Monod parameters were significantly different for the tested PAHs. S. paucimobilis completely degraded all the components in binary and ternary mixtures; however, the initial degradation rates of individual components decreased in the presence of competitive PAHs. Results from the mixture experiments indicate competitive interactions, demonstrated mathematically. The generated model appropriately predicted the biodegradation kinetics in mixtures using parameter estimates from the sole substrate experiments, validating the hypothesis of a common rate-determining step. Biodegradation kinetics in mixtures were affected by the affinity coefficients of the co-occurring PAHs and mixture composition. Experiments with equal concentrations of substrates demonstrated the effect of concentration on competitive inhibition. Ternary experiments with naphthalene, 1,5-dimethylnaphthalene and 1-methylfluorene revealed delayed degradation, where depletion of naphthalene and 1,5-dimethylnapthalene occurred rapidly only after the complete removal of 1-methylfluorene. The substrate interactions observed in mixtures require a multisubstrate model to account for simultaneous degradation of substrates. PAH contaminated sites are far more complex than even ternary mixtures; however these studies clearly demonstrate the effect that interactions can have on individual chemical kinetics. Consequently, predicting natural or enhanced degradation of PAHs cannot be based on single compound kinetics as this assumption would likely overestimate the rate of disappearance.
Collapse
Affiliation(s)
- Anuradha M Desai
- Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, USA.
| | | | | | | |
Collapse
|
17
|
Grochowalski AR, Cooper DG, Nicell JA. Effect of surfactants on plasticizer biodegradation by Bacillus subtilis ATCC 6633. Biodegradation 2006; 18:283-93. [PMID: 17080301 DOI: 10.1007/s10532-006-9062-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Accepted: 06/02/2006] [Indexed: 11/25/2022]
Abstract
The biodegradation of plasticizers has been previously shown to result in the accumulation of metabolites that are more toxic than the initial compound. The present work shows that the pattern of degradation of di-2-ethylhexyl adipate by Bacillus subtilis can be significantly altered by the presence of biosurfactants, such as surfactin, or synthetic surfactants, such as Pluronic L122. In particular, this work confirms that the monoester, mono-2-ethylhexyl adipate, is a metabolite in the breakdown of the plasticizer. This metabolite was proposed but not observed in earlier studies. Toxicity measurements showed it to be significantly more toxic than the plasticizer. Thus, the effect of the surfactants was to significantly increase the accumulation of one or both of the two most toxic metabolites; i.e., the monoester and 2-ethylhexanol. It was proposed that the most likely cause of the effect of the surfactants was the sequestering of these two metabolites into mixed micelles, resulting in their reduced availability for further degradation.
Collapse
Affiliation(s)
- Adam R Grochowalski
- Department of Chemical Engineering, McGill University, 3610 University, Montreal, Quebec, Canada
| | | | | |
Collapse
|
18
|
Xia XH, Yu H, Yang ZF, Huang GH. Biodegradation of polycyclic aromatic hydrocarbons in the natural waters of the Yellow River: effects of high sediment content on biodegradation. CHEMOSPHERE 2006; 65:457-66. [PMID: 16540147 DOI: 10.1016/j.chemosphere.2006.01.075] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Revised: 11/13/2005] [Accepted: 01/25/2006] [Indexed: 05/07/2023]
Abstract
The contamination of polycyclic aromatic hydrocarbons (PAHs) has become one of the major problems in the Yellow River of China. As the Yellow River is the most turbid large river in the world, it remains unknown to which extent the high suspended sediment content in the river may affect the fate and effect of PAHs. Here we report the effect of sediment on biodegradation of chrysene, benzo(a)pyrene and benzo(g,h,i)perylene with phenanthrene as a co-metabolism substrate in natural waters from the Yellow River. Biodegradation kinetics of the PAHs in the river water with various levels of sediment contents were studied in the laboratory by fitting with a biodegradation kinetics model for organic compounds not supporting growth. The results indicated that the biodegradation rates of PAHs increased with the sediment content in the water. When the sediment contents were 0, 4 and 10 g/l, the biodegradation rate constants of chrysene with the initial concentration of 3.80 microg/l were 0.053, 0.084 and 0.111 d(-1), respectively. Further studies suggested the enhanced biodegradation rate in the presence of sediment was caused by the following mechanisms: (1) the population of PAH-degrading bacteria in the water system was found to increase with the sediment content; the bacteria population on sediment phase was far greater than that on water phase during the cultivation process; (2) the sorption of PAHs on the sediment phase was well described by the dual adsorption-partition model. Although the sorption capacity of PAH per unit weight of sediment decreased with the increase of the sediment content, the amount of sorbed PAH increased with the sediment content; and, (3) the desorption of PAHs from the solid phase led to a higher concentration near the water-sediment interface. Since the bacteria were also attached to the interface, this resulted in an increased contact chance between the bacteria and PAHs.
Collapse
Affiliation(s)
- X H Xia
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | | | | | | |
Collapse
|
19
|
Christofi N, Ivshina IB. Microbial surfactants and their use in field studies of soil remediation. J Appl Microbiol 2003; 93:915-29. [PMID: 12452947 DOI: 10.1046/j.1365-2672.2002.01774.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- N Christofi
- Pollution Research Unit, School of Life Sciences, Napier University, Edinburgh, Scotland, UK.
| | | |
Collapse
|