Phenolic compounds in water and the implications for rapid detection of indicator micro-organisms using ß-D-Galactosidase and ß-D-Glucuronidase

Abboo, Sagaran

Title: Phenolic compounds in water and the implications for rapid detection of indicator micro-organisms using ß-D-Galactosidase and ß-D-Glucuronidase
Creator: Abboo, Sagaran
Subject: Water -- Purification -- Biological treatment
Subject: Pollutants -- Biodegradation
Subject: Phenol
Subject: Organic water pollutants
Subject: Water quality biological assessment
Subject: Water -- Pollution
Date Issued: 2009
Date: 2009
Type: Thesis
Type: Masters
Type: MSc
Identifier: vital:3978
Identifier: http://hdl.handle.net/10962/d1004037
Identifier: Water -- Purification -- Biological treatment
Identifier: Pollutants -- Biodegradation
Identifier: Phenol
Identifier: Organic water pollutants
Identifier: Water quality biological assessment
Identifier: Water -- Pollution
Description: Faecal contamination in water is detected using appropriate microbial models such as total coliforms, faecal coliforms and E. coli. Βeta-D-Galactosidase (β-GAL) and Beta-D-glucuronidase (β-GUD) are two marker enzymes that are used to test for the presence of total coliforms and E. coli in water samples, respectively. Various assay methods have been developed using chromogenic and fluorogenic substrates. In this study, the chromogenic substrates chlorophenol red β-D-galactopyranoside (CPRG) for β-GAL and p-nitrophenyl-β-D-galactopyranoside (PNPG) for β-GUD were used. Potential problems associated with this approach include interference from other organisms present in the environment (e.g. plants, algae and other bacteria), as well as the presence of certain chemicals, such as phenolic compounds in water. Phenolic compounds are present in the aquatic environment due to their extensive industrial applications. The USA Enviromental Protection Agency (EPA) lists 11 Priority Pollutant Phenols (PPP) due to their high level of toxicity. This study investigated the interfering effects of the eleven PPP found in water on the enzyme activities of both the β-GAL and β-GUD enzyme assays. The presence of these PPP in the β-GAL and β-GUD enzyme assays showed that over and underestimation of activity may occur due to inhibition or activation of these enzymes. Three types of inhibition to enzyme activities were identified from double reciprocal Lineweaver-Burk plots. The inhibition constants (Ki) were determined for all inhibitory phenolic compounds from appropriate secondary plots. Furthermore, this study presented a validated reverse phase high performance liquid chromatography (RP-HPLC) method, developed for the simultaneous detection, separation and determination of all eleven phenolic compounds found in the environment. This method demonstrated good linearity, reproducibility, accuracy and sensitivity. Environmental water samples were collected from rivers, streams, industrial sites and wastewater treatment plant effluent. These samples were extracted and concentrated using a solid phase extraction (SPE) procedure prior to analysis employing the newly developed HPLC method in this study. Seasonal variations on the presence of the PPP in the environment were observed at certain collection sites. The concentrations found were between 0.033 μg/ml for 2,4-dinitrophenol in a running stream to 0.890 mg/ml for pentachlorophenol from an tannery industrial site. These concentrations of phenolic compounds found in these environments were able to interfere with the β-GAL and β-GUD enzyme assays.
Format: xx, 103 p.: ill. (some co.), charts
Format: pdf
Publisher: Rhodes University
Publisher: Faculty of Science, Biochemistry, Microbiology and Biotechnology
Language: English
Rights: Abboo, Sagaran

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Abboo, Sagaran (Dr)

RU Department of Biochemistry, Microbiology and Biotechnology (end of 2014)

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