Toxicity Testing in Wastewater Treatment Plants Using Microorganisms

Bitton, Gabriel

doi:10.1002/0471263397.env061

Cited by 16 publications

(20 citation statements)

References 60 publications

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“…Enzymes, namely, esterases, have been recognised as potentially useful for the detection of early responses to toxicants in a variety of microorganisms (Dorsey et al 1989;Blaise et al 2000;Bitton 2005;Peperzak and Brussaard 2011). Esterase activity has been evaluated using fluorescein diacetate (FDA).…”

Section: Introductionmentioning

confidence: 99%

Use of a fluorescence-based approach to assess short-term responses of the alga Pseudokirchneriella subcapitata to metal stress

Machado

Soares

2014

J Appl Phycol

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This work explores the use of fluorescent probes to evaluate the responses of the green alga Pseudokirchneriella subcapitata to the action of three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II) for a short time (6 h). The toxic effect of the metals on algal cells was monitored using the fluorochromes SYTOX Green (SG, membrane integrity), fluorescein diacetate (FDA, esterase activity) and rhodamine 123 (Rh123, mitochondrial membrane potential). The impact of metals on chlorophyll a (Chl a) autofluorescence was also evaluated. Esterase activity was the most sensitive parameter. At the concentrations studied, all metals induced the loss of esterase activity. SG could be used to effectively detect the loss of membrane integrity in algal cells exposed to 0.32 or 1.3 μmol L −1 Cu(II). Rh123 revealed a decrease in the mitochondrial membrane potential of algal cells exposed to 0.32 and 1.3 μmol L −1 Cu(II), indicating that mitochondrial activity was compromised. Chl a autofluorescence was also affected by the presence of Cr(VI) and Cu(II), suggesting perturbation of photosynthesis. In conclusion, the fluorescence-based approach was useful for detecting the disturbance of specific cellular characteristics. Fluorescent probes are a useful diagnostic tool for the assessment of the impact of toxicants on specific targets of P. subcapitata algal cells.

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Section: Introductionmentioning

confidence: 99%

Use of a fluorescence-based approach to assess short-term responses of the alga Pseudokirchneriella subcapitata to metal stress

Machado

Soares

2014

J Appl Phycol

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“…Esterases have been recognized as a potential useful biomarker and alternative endpoint for the detection of early responses in a variety of microorganisms (Dorsey et al 1989;Blaise et al 2000;Bitton 2005; Peperzak and Brussaard 2011) to different toxicants. Esterases were used to evaluate the toxicity of heavy metals, such as Cd, Cu, Hg, Pb, and Zn (Arsenault et al 1993;Snell et al 1996;Franklin et al 2001), organic compounds such as phenol and naphthol (Snell et al 1996), brominated flame retardant (Debenest et al 2011), pesticides and insecticides (Gilbert et al 1992;Snell et al 1996), and in natural samples like surface seawater (Gilbert et al 1992), freshwater sediments , interstitial water (Cote et al 1998), and acid mine drainage (Regel et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Optimization of a Microplate-Based Assay to Assess Esterase Activity in the Alga Pseudokirchneriella subcapitata

Machado

Soares

2012

Water Air Soil Pollut

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The present work describes the optimiza-tion of a short-term assay, based on the inhibition of the esterase activity of the alga Pseudokirchneriella subcapitata, in a microplate format. The optimization of the staining procedure showed that the incubation of the algal cells with 20 μmolL −1 fluorescein diac-etate (FDA) for 40 min allowed discrimination be-tween metabolic active and inactive cells. The short-term assay was tested using Cu as toxicant. For this purpose, algal cells, in the exponential or stationary phase of growth, were exposed to the heavy metal in growing conditions. After 3 or 6 h, cells were subse-quently stained with FDA, using the optimized proce-dure. For Cu, the 3-and 6-h EC 50 values, based on the inhibition of the esterase activity of algal cells in the exponential phase of growth, were 209 and 130 μg L −1 , respectively. P. subcapitata cells, in the stationary phase of growth, displayed higher effective concentra-tion values than those observed in the exponential phase. The 3-and 6-h EC50 values for Cu, for cells in the stationary phase, were 443 and 268 μgL−1, respectively. This short-term microplate assay showed to be a rapid endpoint for testing toxicity using the alga P. subcapitata. The small volume required, the simplicity of the assay (no washing steps), and the automatic reading of the fluorescence make the assay particularly well suited for the evaluation of the toxic-ity of a high number of environmental samples.

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“…The biological treatment of industrial wastewaters by mixed microbial communities is, however, often disrupted by organic (e.g., chlorinated organics, phenolic compounds, surfactants, and herbicides) and inorganic (e.g., heavy metals, sulfides, and ammonia) chemicals present in the wastewater stream (7,52). This disruption of biological processes results in inhibited nitrification, decreased carbon removal, and modification of sludge compaction properties (7,29). Little is known about the composition of mixed microbial communities in reactors when biological processes are disrupted by or recovering from xenobiotic shocks.…”

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confidence: 99%

Bioaugmentation as a Tool To Protect the Structure and Function of an Activated-Sludge Microbial Community against a 3-Chloroaniline Shock Load

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Top

Verstraete

et al. 2003

Appl Environ Microbiol

230

142

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Bioaugmentation of bioreactors focuses on the removal of xenobiotics, with little attention typically paid to the recovery of disrupted reactor functions such as ammonium-nitrogen removal. Chloroanilines are widely used in industry as a precursor to a variety of products and are occasionally released into wastewater streams. This work evaluated the effects on activated-sludge reactor functions of a 3-chloroaniline (3-CA) pulse and bioaugmentation by inoculation with the 3-CA-degrading strain Comamonas testosteroni I2 gfp. Changes in functions such as nitrification, carbon removal, and sludge compaction were studied in relation to the sludge community structure, in particular the nitrifying populations. Denaturing gradient gel electrophoresis (DGGE), real-time PCR, and fluorescent in situ hybridization (FISH) were used to characterize and enumerate the ammonia-oxidizing microbial community immediately after a 3-CA shock load. Two days after the 3-CA shock, ammonium accumulated, and the nitrification activity did not recover over a 12-day period in the nonbioaugmented reactors. In contrast, nitrification in the bioaugmented reactor started to recover on day 4. The DGGE patterns and the FISH and real-time PCR data showed that the ammonia-oxidizing microbial community of the bioaugmented reactor recovered in structure, activity, and abundance, while the number of ribosomes of the ammonia oxidizers in the nonbioaugmented reactor decreased drastically and the community composition changed and did not recover. The settleability of the activated sludge was negatively influenced by the 3-CA addition, with the sludge volume index increasing by a factor of 2.3. Two days after the 3-CA shock in the nonbioaugmented reactor, chemical oxygen demand (COD) removal efficiency decreased by 36% but recovered fully by day 4. In contrast, in the bioaugmented reactor, no decrease of the COD removal efficiency was observed. This study demonstrates that bioaugmentation of wastewater reactors to accelerate the degradation of toxic chlorinated organics such as 3-CA protected the nitrifying bacterial community, thereby allowing faster recovery from toxic shocks.The main purpose of a wastewater treatment plant is to convert the organics present in an incoming wastewater stream to N 2 and CO 2 as well as to reduce the amount of suspended solids entering the environment. The biological treatment of industrial wastewaters by mixed microbial communities is, however, often disrupted by organic (e.g., chlorinated organics, phenolic compounds, surfactants, and herbicides) and inorganic (e.g., heavy metals, sulfides, and ammonia) chemicals present in the wastewater stream (7,52). This disruption of biological processes results in inhibited nitrification, decreased carbon removal, and modification of sludge compaction properties (7,29). Little is known about the composition of mixed microbial communities in reactors when biological processes are disrupted by or recovering from xenobiotic shocks. Most investigators focus on xenobiotic degradation, bu...

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Toxicity Testing in Wastewater Treatment Plants Using Microorganisms

Abstract: Introduction Survey of Microbiotests for Monitoring Toxicity in Wastewater Treatment Plants

Cited by 16 publications

References 60 publications

Use of a fluorescence-based approach to assess short-term responses of the alga Pseudokirchneriella subcapitata to metal stress

Use of a fluorescence-based approach to assess short-term responses of the alga Pseudokirchneriella subcapitata to metal stress

Optimization of a Microplate-Based Assay to Assess Esterase Activity in the Alga Pseudokirchneriella subcapitata

Bioaugmentation as a Tool To Protect the Structure and Function of an Activated-Sludge Microbial Community against a 3-Chloroaniline Shock Load

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