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Feng JR, Ni HG. Effects of heavy metals and metalloids on the biodegradation of organic contaminants. ENVIRONMENTAL RESEARCH 2024; 246:118069. [PMID: 38160966 DOI: 10.1016/j.envres.2023.118069] [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: 09/03/2023] [Revised: 12/22/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Heavy metals and metalloids (HMMs) inhibit the biodegradation of organic pollutants. The degree of inhibition depends not only on the concentration and bioavailability of HMMs but also on additional factors, such as environmental variables (e.g., inorganic components, organic matter, pH, and redox potential), the nature of the metals, and microbial species. Based on the degradation pattern and metal concentrations causing half biodegradation rate reductions (RC50s), the inhibition of biodegradation was: Hg2+, As2O3 > Cu2+, Cd2+, Pb2+, Cr3+ > Ni2+, Co2+ > Mn2+, Zn2+ > Fe3+. Four patterns were observed: inhibition increases with increasing metal concentration; low concentrations stimulate, while high concentrations inhibit; high concentrations inhibit less; and mild inhibition remains constant. In addition, metal ion mixtures have more complex inhibitory effects on the degradation of organic pollutants, which may be greater than, similar to, or less than that of individual HMMs. Finally, the inhibitory mechanism of HMMs on biodegradation is reviewed. HMMs generally have little impact on the biodegradation pathway of organic pollutants for bacterial strains. However, when pollutants are biodegraded by the community, HMMs may activate microbial populations harbouring different transformation pathways. HMMs can affect the biodegradation efficiency of organic pollutants by changing the surface properties of microbes, interfering with degradative enzymes, and interacting with general metabolism.
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Affiliation(s)
- Jin-Ru Feng
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
| | - Hong-Gang Ni
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China.
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Zhao X, Jia P, Chen L, Yang Y, Yang Y, Gao D. Combination of biodegradation and fenton process for efficient removal of PDM/ZnO. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114013. [PMID: 34735834 DOI: 10.1016/j.jenvman.2021.114013] [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: 01/13/2021] [Revised: 09/26/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
In the present study, an investigation was conducted on the removal of polydiallyldimethylammonium chloride-acrylic-acrylamide-hydroxyethyl acrylate/ZnO nanocomposites (PDM/ZnO) through biodegradation and Fenton process coupled treatments. As revealed from the results of the chemical oxygen demand, the total organic carbon, the biochemical oxygen demand and the CO2 production analysis, PDM/ZnO could be partially biodegraded. The optimal initial pH, the mixed liquid suspended solids concentration and additional carbon source (glucose) dosage in the biodegradation were 7.0, 4.0 g/L and 1.0 g/L, respectively. On the whole, NaCl, the coexisted metal cations (Cu2+, Zn2+ and Cr3+) and additional NH4Cl inhibited the biodegradation of PDM/ZnO. PDM/ZnO was suggested to adversely affect on microbial community structure and activity. Optimum conditions for Fenton treatment were 50 mg/L Fe2+, 20 mL/L H2O2 and pH 2.0. Biodegradation showed that 64% of PDM/ZnO was removed. Besides, the combination of Fenton post-treatment could achieve an over 97% removal of PDM/ZnO. Thus, Fenton process combined biodegradation pre-treatment can act as an effective method to remove PDM/ZnO.
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Affiliation(s)
- Xia Zhao
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China; Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science & Technology, Xi'an, 710021, China.
| | - Pengju Jia
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China
| | - Ling Chen
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China
| | - Yong Yang
- School of Arts and Sciences, Shaanxi University of Science & Technology, Xi'an, 710021, China
| | - Yuhao Yang
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China; Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science & Technology, Xi'an, 710021, China
| | - Dangge Gao
- College of Bioresources Chemistry and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China
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Speciation transformation and bioavailability of heavy metals during biogas production from coal slime. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108208] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Inoue D, Tsunoda T, Sawada K, Yamamoto N, Sei K, Ike M. Stimulatory and inhibitory effects of metals on 1,4-dioxane degradation by four different 1,4-dioxane-degrading bacteria. CHEMOSPHERE 2020; 238:124606. [PMID: 31446278 DOI: 10.1016/j.chemosphere.2019.124606] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/26/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
This study evaluates the effects of various metals on 1,4-dioxane degradation by the following four bacteria: Pseudonocardia sp. D17; Pseudonocardia sp. N23; Mycobacterium sp. D6; and Rhodococcus aetherivorans JCM 14343. Eight transition metals [Co(II), Cu(II), Fe(II), Fe(III), Mn(II), Mo(VI), Ni(II), and Zn(II)] were used as the test metals. Results revealed, for the first time, that metals had not only inhibitory but also stimulatory effects on 1,4-dioxane biodegradation. Cu(II) had the most severe inhibitory effects on 1,4-dioxane degradation by all of the test strains, with significant inhibition at concentrations as low as 0.01-0.1 mg/L. This inhibition was probably caused by cellular toxicity at higher concentrations, and by inhibition of degradative enzymes at lower concentrations. In contrast, Fe(III) enhanced 1,4-dioxane degradation by Mycobacterium sp. D6 and R. aetherivorans JCM 14343 the most, while degradation by the two Pseudonocardia strains was stimulated most notably in the presence of Mn(II), even at concentrations as low as 0.001 mg/L. Enhanced degradation is likely caused by the stimulation of soluble di-iron monooxygenases (SDIMOs) involved in the initial oxidation of 1,4-dioxane. Differences in the stimulatory effects of the tested metals were likely associated with the particular SDIMO types in the test strains.
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Affiliation(s)
- Daisuke Inoue
- Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Tsubasa Tsunoda
- Environment and Medical Sciences Course, Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa, 252-0373, Japan
| | - Kazuko Sawada
- Department of Health Science, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa, 252-0373, Japan
| | - Norifumi Yamamoto
- Technology Center, Taisei Corporation, 344-1 Nase-cho, Totsuka-ku, Yokohama, Kanagawa, 245-0051, Japan
| | - Kazunari Sei
- Environment and Medical Sciences Course, Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa, 252-0373, Japan; Department of Health Science, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa, 252-0373, Japan
| | - Michihiko Ike
- Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Ningyan PENG, Guofei DAI, Wei ZHANG, Gang GE, Ping YANG, Chunjing GUO, Yuanyuan FANG. Differences in nutrition condition and algae population in different areas of Poyang Lake. ACTA ACUST UNITED AC 2018. [DOI: 10.18307/2018.0512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Kalidhasan S, Ben-Sasson M, Dror I, Carmieli R, Schuster EM, Berkowitz B. Oxidation of aqueous organic pollutants using a stable copper nanoparticle suspension. CAN J CHEM ENG 2016. [DOI: 10.1002/cjce.22652] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Sethu Kalidhasan
- Department of Earth and Planetary Sciences; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Moshe Ben-Sasson
- Department of Earth and Planetary Sciences; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Ishai Dror
- Department of Earth and Planetary Sciences; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Raanan Carmieli
- Department of Chemical Research Support; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Elaine M. Schuster
- Department of Earth and Planetary Sciences; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Brian Berkowitz
- Department of Earth and Planetary Sciences; Weizmann Institute of Science; Rehovot 7610001 Israel
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Aparicio J, Solá MZS, Benimeli CS, Amoroso MJ, Polti MA. Versatility of Streptomyces sp. M7 to bioremediate soils co-contaminated with Cr(VI) and lindane. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2015; 116:34-39. [PMID: 25749405 DOI: 10.1016/j.ecoenv.2015.02.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 06/04/2023]
Abstract
The aim of this work was to study the impact of environmental factors on the bioremediation of Cr(VI) and lindane contaminated soil, by an actinobacterium, Streptomyces sp. M7, in order to optimize the process. Soil samples were contaminated with 25 µg kg(-1) of lindane and 50 mg kg(-1) of Cr(VI) and inoculated with Streptomyces sp. M7. The lowest inoculum concentration which simultaneously produced highest removal of Cr(VI) and lindane was 1 g kg(-1). The influence of physical and chemical parameters was assessed using a full factorial design. The factors and levels tested were: Temperature: 25, 30, 35°C; Humidity: 10%, 20%, 30%; Initial Cr(VI) concentration: 20, 50, 80 mg kg(-1); Initial lindane concentration: 10, 25, 40 µg kg(-1). Streptomyces sp. M7 exhibited strong versatility, showing the ability to bioremediate co-contaminated soil samples at several physicochemical conditions. Streptomyces sp. M7 inoculum size was optimized. Also, it was fitted a model to study this process, and it was possible to predict the system performance, knowing the initial conditions. Moreover, optimum temperature and humidity conditions for the bioremediation of soil with different concentrations of Cr(VI) and lindane were determined. Lettuce seedlings were a suitable biomarker to evaluate the contaminants mixture toxicity. Streptomyces sp. M7 carried out a successful bioremediation, which was demonstrated through ecotoxicity test with Lactuca sativa.
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Affiliation(s)
- JuanDaniel Aparicio
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET. Av. Belgrano y Pasaje Caseros. 4000 Tucumán, Argentina; Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán. Ayacucho 491, 4000 Tucumán, Argentina
| | - María Zoleica Simón Solá
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET. Av. Belgrano y Pasaje Caseros. 4000 Tucumán, Argentina; Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán. Ayacucho 491, 4000 Tucumán, Argentina
| | - Claudia Susana Benimeli
- Unidad de Administración Territorial, Centro Científico Tecnológico, CCT-CONICET-Tucumán, Crisóstomo Álvarez 722, 4000 Tucumán, Argentina; Universidad del Norte Santo Tomás de Aquino (UNSTA), 4000 Tucumán, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Catamarca. Esquiú 799, 4700 Catamarca, Argentina
| | - María Julia Amoroso
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET. Av. Belgrano y Pasaje Caseros. 4000 Tucumán, Argentina; Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán. Ayacucho 491, 4000 Tucumán, Argentina; Universidad del Norte Santo Tomás de Aquino (UNSTA), 4000 Tucumán, Argentina
| | - Marta Alejandra Polti
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET. Av. Belgrano y Pasaje Caseros. 4000 Tucumán, Argentina; Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán. Miguel Lillo 205, 4000 Tucumán, Argentina.
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Wannoussa W, Masy T, Lambert SD, Heinrichs B, Tasseroul L, Al-Ahmad A, Weekers F, Thonar P, Hiligsmann S. Effect of Iron Nanoparticles Synthesized by a Sol-Gel Process on <i>Rhodococcus erythropolis</i> T902.1 for Biphenyl Degradation. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/jwarp.2015.73021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Xu G, Wang J. Biodegradation of decabromodiphenyl ether (BDE-209) by white-rot fungus Phlebia lindtneri. CHEMOSPHERE 2014; 110:70-77. [PMID: 24880601 DOI: 10.1016/j.chemosphere.2014.03.052] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 03/09/2014] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
This work investigated degradation of decabromodiphenyl ether (BDE-209) by Phlebia lindtneri under the influence of glucose and heavy metals (Cd(2+), Cu(2+) or Pb(2+)). The results showed that adding glucose could markedly promote BDE-209 biodegradation. In the absence of heavy metals, 77.3% BDE-209 was degraded within 30d when dealing with 20mgL(-1) BDE-209. BDE-209 degradation was stimulated at low concentrations of Cu and Pb, whereas inhibited at higher levels of metals. The culture pH tended to decrease with time. Adding lower concentrations of Cu (⩽5.0mgL(-1)) enhanced laccase activity. No stimulatory effect was observed on laccase activity in the presence of Cd or Pb. Ecotoxicity in the culture significantly increased at the late stage of the experiment. Bromine ions were released and the debromination rate of BDE-209 was much lower than its degradation rate. The fungus could degrade BDE-209 through debromination, hydroxylation, and ring-opening reactions.
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Affiliation(s)
- Guiying Xu
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400067, China.
| | - Jiangbo Wang
- Chongqing Hongyu Precision Industrial Co., Ltd., Chongqing 402760, China
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Pornwongthong P, Mulchandani A, Gedalanga PB, Mahendra S. Transition Metals and Organic Ligands Influence Biodegradation of 1,4-Dioxane. Appl Biochem Biotechnol 2014; 173:291-306. [DOI: 10.1007/s12010-014-0841-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 02/27/2014] [Indexed: 10/25/2022]
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Kim BN, Le TH, Hong E, Ahn JM, Kim YH, Min J. Effects of different mineral supplements on fertilization of phenol-contaminated soils by Corynebacterium glutamicum. BIOTECHNOL BIOPROC E 2014. [DOI: 10.1007/s12257-013-0768-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Shi G, Yin H, Ye J, Peng H, Li J, Luo C. Effect of cadmium ion on biodegradation of decabromodiphenyl ether (BDE-209) by Pseudomonas aeruginosa. JOURNAL OF HAZARDOUS MATERIALS 2013; 263 Pt 2:711-717. [PMID: 24220201 DOI: 10.1016/j.jhazmat.2013.10.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 10/13/2013] [Accepted: 10/17/2013] [Indexed: 06/02/2023]
Abstract
The influence of Cd(II) ions on the degradation of decabromodiphenyl ether (BDE-209) by an aerobic degrading strain, Pseudomonas aeruginosa, was investigated. The results demonstrated that the strain P. aeruginosa exhibited a high level of resistance against cadmium toxicity, and Cd(II) ions of different concentrations possessed mixed reactions on BDE-209 bioremoval. The degradation efficiency was stimulated at low concentrations of Cd(II) ions (≤ 1 mg L(-1)) but inhibited at higher levels (≥ 5 mg L(-1)). Subsequent analyses revealed that the increase of cell hydrophobicity and membrane permeability were two main factors for Cd(II) ions of low concentrations to accelerate BDE-209 degradation. However, inhibition effect by high concentrations of Cd(II) ions was mainly attributed to the negative impact of metals on growth and metabolism of the strain. It was also showed through cellular distribution of BDE-209 that different concentration of Cd(II) ions affected the amount of BDE-209 inside or outside the cell at different incubation time.
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Affiliation(s)
- Guangyu Shi
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640, China
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Moreira IS, Amorim CL, Carvalho MF, Ferreira AC, Afonso CM, Castro PML. Effect of the metals iron, copper and silver on fluorobenzene biodegradation by Labrys portucalensis. Biodegradation 2012; 24:245-55. [PMID: 22842857 DOI: 10.1007/s10532-012-9581-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 07/21/2012] [Indexed: 11/25/2022]
Abstract
Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe(2+) to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu(2+) was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag(+) was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag(+) to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag(+) resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu(2+) or Ag(+) suggest inhibition of the key enzyme of FB metabolism-catechol 1,2-dioxygenase.
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Affiliation(s)
- Irina S Moreira
- Centro de Biotecnologia e Química Fina (CBQF), Escola Superior de Biotecnologia, Centro Regional do Porto, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200-072, Porto, Portugal
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Fogel R, Limson JL. Probing fundamental film parameters of immobilized enzymes--towards enhanced biosensor performance. Part II-Electroanalytical estimation of immobilized enzyme performance. Enzyme Microb Technol 2011; 49:153-9. [PMID: 22112402 DOI: 10.1016/j.enzmictec.2011.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 02/17/2011] [Accepted: 05/07/2011] [Indexed: 11/17/2022]
Abstract
The method of immobilization of a protein has a great influence on the overall conformation, and hence, functioning of the protein. Thus, a greater understanding of the events undergone by the protein during immobilization is key to manipulating the immobilization method to produce a strategy that influences the advantages of immobilization while minimizing their disadvantages in biosensor design. In this, the second paper of a two-part series, we have assessed the kinetic parameters of thin-film laccase monolayers, covalently attached to SAMs differing in spacer-arm length and lateral density of spacer arms. This was achieved using chronoamperometry and an electroactive product (p-benzoquinone), which was modeled in a non-linear regressional fashion to extract the relevant parameters. Finally, comparisons between the kinetic parameters presented in this paper and the rheological parameters of laccase monolayers immobilized in the same manner (Part I of this two paper series) were performed. Improvements in the maximal enzyme-catalysed current, i(max), the apparent Michaelis-Menten constant, K(m) and the apparent biosensor sensitivity were noted for most of the surfaces with increasing linker length. Decreasing the lateral density of the spacer-arms brought about a general improvement in these parameters, which is attributed to the decrease in multiple points of immobilization undergone by functional proteins. Finally, comparisons between rheological data and kinetics data showed that the degree of viscosity exhibited by protein films has a negative influence on attached protein layers, while enhanced protein hydration levels (assessed piezoelectrically from data obtained in Paper 1) has a positive effect on those surfaces comprising rigidly bound protein layers.
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Affiliation(s)
- R Fogel
- Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, P.O. Box 94, Grahamstown, South Africa
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Ramakrishnan B, Megharaj M, Venkateswarlu K, Sethunathan N, Naidu R. Mixtures of environmental pollutants: effects on microorganisms and their activities in soils. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2011; 211:63-120. [PMID: 21287391 DOI: 10.1007/978-1-4419-8011-3_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Soil is the ultimate sink for most contaminants and rarely has only a single contaminant. More than is generally acknowledge, environmental pollutants exist as mixtures (organic-organic, inorganic-inorganic, and organic-inorganic). It is much more difficult to study chemical mixtures than individual chemicals, especially in the complex soil environment. Similarly, understanding the toxicity of a chemical mixture on different microbial species is much more complex, time consuming and expensive, because multiple testing designs are needed for an increased array of variables. Therefore, until now, scientific enquiries worldwide have extensively addressed the effects of only individual pollutants toward nontarget microorganisms. In this review, we emphasize the present status of research on (i) the environmental occurrence of pollutant mixtures; (ii) the interactions between pollutant mixtures and ecologically beneficial microorganisms; and (iii) the impact of such interactions on environmental quality. We also address the limitations of traditional cultivation based methods for monitoring the effects of pollutant mixtures on microorganisms. Long-term monitoring of the effects of pollutant mixtures on microorganisms, particularly in soil and aquatic ecosystems, has received little attention. Microbial communities that can degrade or can degrade or can develop tolerance to, or are inhibited by chemical mixtures greatly contribute to resilience and resistance in soil environments. We also stress in this review the important emerging trend associated with the employment of molecular methods for establishing the effects of pollutant mixtures on microbial communities. There is currently a lack of sufficient cogent toxicological data on chemical mixtures for making informed decision making in risk assessment by regulators. Therefore, not only more toxicology information on mixtures is needed but also there is an urgent need to generate sufficient, suitable, and long-term modeling data that have higher predictability when assessing pollutant mixture effects on microorganisms. Such data would improve risk assessment at contaminated sites and would help devise more effective bioremediation strategies.
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