Ecology of biological sulfate removal

Liss, Jago Milan (2003-04)

Thesis (MSc)--Stellenbosch University, 2003.

Thesis

ENGLISH ABSTRACT: A laboratory-scale model was used to simulate biological sulfate removal. The focus of the research was microbial community response, such as the relative abundance of functional groups to changes in influent medium composition. Specific oligonucleotide probes were obtained that recognised sulfate reducing bacteria (SRB) within the biofilm community. Terminal restriction fragment length polymorphism (T-RFLP) and BIOLOG™ Ecoplate analyses were used to study the SRB community when provided with sodium lactate, sucrose or ethanol as carbon sources in complex Postgate C broth. These two analyses, as well as conventional methods, were applied to follow succession patterns in the laboratory scale reactors, and to determine the possible presence and relative abundance of microorganisms other than bacteria under sulfate reducing conditions. T-RFLP and BIOLOG™ Ecoplate analyses indicated a few dominant organisms in the community and a slight decline after a shift to another carbon source. Fluorescent hybridization showed higher numbers of SRB relative to the total microbial community than conventional culturing techniques. Furthermore, microscopic observations showed that not only SRB and other bacteria, but also yeast and filamentous fungi were integrated in a biofilm under sulfate reducing conditions. These microscopic observations were verified with fluorescent in situ hybridization (FISH) and yeast Live I Dead viability probes.

AFRIKAANSE OPSOMMING: Biologiese sulfaat-verwydering is met behulp van "n laboratoriumskaalmodel gesimuleer. Die doel van die navorsing was om die respons van "n mikrobiese gemeenskap met byvoorbeeld die relatiewe hoeveelheid van funksionele groepe op veranderinge in invloeiende medium samestelling te bestudeer. Spesifieke oligonukleotiedpeilers wat sulfaatreduserende bakterieë (SRB) in "n biofilmgemeenskap kan opspoor is gebruik. Die SRB gemeenskap is bestudeer met behulp van terminale-restriksiefragmentlengtepolimorfisme (TRFLP) en BIOLOGTM Ecoplate analise waar natriumlaktaat, sukrose of etanol as koolstofbronne toegevoeg is. Hierdie twee tipes analise en konvensionele metodes is aangewend om suksessiepatrone in die laboratoriumskaalreaktor te volg en die moontlike teenwoordigheid en relatiewe hoeveelheid van organismes, uitsluitende bakterieë, onder sulfaatreduserende kondisies te bepaal. Analise van T-RFLP en BIOLOGTM Ecoplate het aangedui dat In paar dominante organismes in die gemeenskap teenwoordig was, wat effens afgeneem het na verskuiwing na 'n ander koolstofbron. Fluoresserende hibridisasie het hoër getalle van SRB relatief tot die totale mikrobiese gemeenskap aangedui as konvensionele kultuur tegnieke. Mikroskopiese analises het verder getoon dat benewens SRB en ander bakterieë ook giste en filamentagtige swamme onder sulfaatreduserende kondisies in "n biofilm geïntegreer was. Hierdie mikroskopiese waarneminge is bevestig deur fluoresserende in situ hibridisasie (FISH) en gis Lewe / Dood lewensvatbaarheid peilers.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/53400
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