Assessing the capacity for micropollutants to induce changes in the biofilm EPS composition and yield
| dc.contributor.advisor | Wolfaardt, Gideon M. | en_ZA |
| dc.contributor.advisor | Stone, Wendy | en_ZA |
| dc.contributor.author | Rossouw, Johann Herman | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Science. Dept. of Microbiology. | en_ZA |
| dc.date.accessioned | 2021-12-06T12:34:09Z | |
| dc.date.accessioned | 2021-12-22T14:30:33Z | |
| dc.date.available | 2021-12-06T12:34:09Z | |
| dc.date.available | 2021-12-22T14:30:33Z | |
| dc.date.issued | 2021-12 | |
| dc.description | Thesis (MSc)--Stellenbosch University, 2021. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: A consequence of widespread chemical manufacturing and usage is the increasing presence of a new class of contaminant: micropollutants. Despite the investment of significant resources into the development of novel approaches to wastewater treatment, the removal efficiency of micropollutants has been varied and conflicting between different studies. A notable gap in current research efforts is assessing the capacity for chronic micropollutant exposure to alter the main mechanisms contributing to their removal in secondary wastewater treatment. The aim of this study was three-fold. First, to investigate the comparative homogeneity of the Slime-EPS matrix composition for multi- versus single-species biofilms. Secondly, to attempt to quantify the adsorptive capacity of the Slime-EPS fragment utilizing a published dye-probing analysis protocol. Finally, to assess the capacity for chronic (7-day) micropollutant exposure to influence the composition and yield of the Slime-EPS fragment for a known, biofilm producing Pseudomonas species. Single-species biofilms exhibited a more consistent Slime-EPS composition in terms of their protein: carbohydrate ratio. Dye-probing analysis efforts indicated the capacity for toluidine blue dye to exhibit altered spectral absorbance as a result of increased dimerization – which was found to be influenced by both the introduction of the Slime-EPS itself and increasing concentrations of NaCl. Increasing concentrations of TB dye was shown to induce hypsochromic (blue-) spectral shifts. Ciprofloxacin was found to significantly reduce the biofilm Slime-EPS yield (p < 0.05) following 7 days of continuous exposure, whereas exposure to diclofenac for the same interval had no significant effect on Slime-EPS yield. Neither ciprofloxacin nor diclofenac had a significant effect on the Slime-EPS protein: carbohydrate ratio following 7 days of exposure. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: ‘n Gevolg van chemiese vervaardiding en die gebruik van chemikalieë is die toenemende teenwoordigheid van ‘n nuwe klas van kontaminante: ‘micropollutants’. Ondanks die belegging van hulpbronne tot die ontwikkeling van nuwe benaderings met betrekking tot die behandeling van rioolwater, is die doeltreffendheid van hierdie benaderings wisselend en teenstrydig. 'n Opvallende leemte in huidige navorsingspogings is die beoordeling van die vermoë van chroniese ‘micropollutant’ blootstelling om die meganismes waardeur hulle verwyder word te beinvloed, spesifiek met betrekking to die sekondêre behandelingsproses in rioolwater suiwering. Die doel van hierdie studie was drievoudig. Eerstens om die homogeniteit van die ‘Slime-EPS’ matriks samestelling vir beide multispesie- en enkelspesie-biofilms te ondersoek. Tweedens, om die adsorpsievermoë van die ‘Slime-EPS’ fragment te probeer kwantifiseer deur gebruik te maak van 'n gepubliseerde kleurstof-ondersoek-analise-protokol. Ten slotte, om die vermoë van chroniese (7-dae) blootstelling aan ‘micropollutants’, in terme van laasgenoemde se impak op die samestelling en opbrengs van die ‘Slime-EPS’ fragment, te beoordeel vir 'n bekende, biofilm- produserende Pseudomonas-spesie. Enkel-spesie biofilms vertoon 'n meer konsekwente ‘Slime- EPS’ samestelling in terme van hul proteïen: koolhidraat verhouding. Pogings met die ontleding van kleurstofondersoeke het aangedui dat toluidien-blou kleurstof die vermoë het om veranderde spektrale absorbering te toon as gevolg van verhoogde kleurstof dimerisering – waarskynlik weens die invloed van die ‘Slime-EPS’ bindingsstof self en toenemende konsentrasies NaCl. Dit is bevind dat toenemende konsentrasies TB-kleurstof hipsochromiese (blou-) spektrale verskuiwings veroorsaak. Dit is bevind dat ciprofloxacin die biofilm ‘Slime-EPS’ opbrengs (p <0,05) aansienlik verlaag na 7 dae van deurlopende blootstelling, terwyl blootstelling aan diclofenac vir dieselfde tydsinterval geen noemenswaardige effek op die Slime-EPS opbrengs gehad het nie. Beide ciprofloxacin en diclofenac het geen beduidende uitwerking op die ‘Slime- EPS’ proteïen: koolhidraat verhouding getoon na 7 dae blootstelling nie. | af_ZA |
| dc.description.version | Masters | en_ZA |
| dc.format.extent | ix, 140 pages : illustrations (some color) | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/123943 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Ecotoxicology, EPS matrix | en_ZA |
| dc.subject | Micropollutants -- Purification | en_ZA |
| dc.subject | Biofilms -- Microbiology | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.title | Assessing the capacity for micropollutants to induce changes in the biofilm EPS composition and yield | en_ZA |
| dc.type | Thesis | en_ZA |