Graduation date: 1971

Includes bibliographical references. / 1v. (various pagings) ; / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Comprises four sections: published research papers; abstracts of major conference presentations; mycoplasmological subject and book reviews; and, academic theses. The published research papers comprising the main basis of the submission predominantly report original findings of laboratory investigations within microbiology dealing with Micobacteria, microbial water requirements, and Mollicutes (mycoplasms). / Thesis (D.Sc.)--University of Adelaide, Dept. of Microbiology and Immunology, 1995

Submitted in partial fulfillment of the requirements for the Degree of Master of Technology: Biological Sciences, Technikon Natal, 2000. / This study focussed on the anti-bacterial, anti-fungal and anti-protozoal activity of four plant extracts, maackiain and formononetin from Virgilia oroboides and chlorophorin and lroko from Chlorophora excelsa / M

A microcosm study was performed to investigate the biodegradation potential of BTX compounds in unsaturated soils under aerobic and anaerobic conditions. Toluene was used as a model compound at concentrations of 100 to 200 mg/L. An uncontaminated, groseclose soil ranging in depth from 0 to 18 feet was used in order to observe differences in microbial degradation abilities in shallow subsurface environments. Several metabolic groups were investigated including aerobes, denitrifyers and sulfate reducers. Bacterial densities of these groups were determined at each soil depth. Physical and chemical parameters of the subsurface environments were also investigated to observe their impact on microbial biodegradation potentials. These included changes in soil particle size, moisture content, and pH with increasing depth. Substantial toluene biodegradation took place in some, but not all soils under both aerobic and denitrifying conditions. Biodegradation rates varied considerably among aerobes and denitrifyers in similar environments. In acidic, poorly drained clay soils of 3, 6 and 9 feet, denitrifyers readily degraded toluene while aerobic microorganisms were unable to mineralize the compcund. Evidence of toluene biodegradation by anaerobic bacteria including sulfate reducers was also observed in moist, clay soils although the rates were much slower. Currently, in situ bioremediation techniques for benzene, toluene and xylene compounds almost always rely on indigenous, aerobic organisms to degrade the contaminants. However, results of this study indicate that aerobic organisms capable of biodegradation may not exist in some subsurface environments, even in soils very close to the surface. The physical/chemical properties of unsaturated environments have significant impacts on microbial capabilities as well as the biodegradation potential of contaminants. / Master of Science

There was good correlation between the presence of biochemical and cultural features indicating pathogenicity and the ability to produce enterotoxin, but not to such a degree that these features can be used as an indication of enterotoxin-producing ability. / Master of Science

Thesis (M.Sc. (Microbiology)) --University of Limpopo, 2015 / Five plant species: Ziziphus mucronata, Senna italica, Lantana camara, Ricinus communis and Lippia javanica, were selected for this study based on their use in traditional medicine. In preliminary screening, crude extracts were prepared using hexane, dichloromethane (dcm), acetone and methanol. Phytochemical profiles on Thin Layer Chromatography plates of the extracts were obtained by developing the plates in mobile phases of varying polarity. Tests for compounds such as tannins, flavonoids, alkaloids, phlobatannins, terpenes, steroids, cardiac glycosides and saponins were carried out. Antibacterial activity of the extracts was carried out using microdilution assay for Minimum Inhibitory Concentration and bioautography against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis. Antioxidant activity of the extracts was performed using the 2, 2, diphenyl-1-picrylhydrazyl (DPPH) assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay and Phagoburst test were used to investigate the toxic effects and anti-inflammatory activity of the extracts on mouse Raw 264.7 macrophage cells, respectively. The presence of phytochemicals was observed on the chromatograms after the plates were sprayed with vanillin sulphuric acid reagent. The dcm extracts of the plants showed antibacterial activity against the selected bacterial species on the bioautograms. Senna italica and Z. mucronata showed the most activity bands on the bioautograms. Lippia javanica had the lowest MIC average of 0.56 mg/ml. Antioxidant activity was observed in the extracts of L. javanica and R. communis. The extracts promoted proliferation of the mouse macrophage cells Raw 264.7 at concentrations ranging from 0.31 mg/ml and 0.08 mg/ml. Senna italica leaves were selected for isolation of antibacterial compounds. The isolated compound was analysed on 1H and 13C nuclear magnetic resonance (NMR) and Mass Spectrometry (MS) for structural analysis. The structure could not be elucidated due to impurities in the compound but the tentative structure is a branched chain alkane with at least one ether linkage per repeating unit. Therefore the study shows that there are plant components with biological activities against wound infecting bacteria and a single lead compound was identified. / the National Research Foundation

Please read the abstract in the section 00front of this document / Dissertation (MSc (Biochemistry))--University of Pretoria, 2005. / Biochemistry / unrestricted

The rumen microbiome constitutes a unique genetic resource of plant fiber degrading microbial enzymes that could be used for agricultural and industrial purposes. Anaeromyces mucronatus is a poorly characterized anaerobic lignocellulolytic fungus in the rumen. This thesis aimed at better understanding A. mucronatus YE505 and the particle associated rumen microbiota based on transcriptomic and metatranscriptomic approaches. High quality RNA was isolated from the fiber-associated rumen sample based on an improved RNA extraction method. A transcriptomic study was performed to investigate the expression of the fiber degrading system of A. mucronatus YE505, and the functional diversity of the fiber-associated eukaryotes from the rumen of muskoxen (Ovibos moschatus) was explored by a metatranscriptomic study. Much carbohydrate degradation related protein modules were detected. This study established effective approaches to characterizing the functional contents of rumen eukaryotic microbiome as well as rumen fungi, and identified several candidate genes that merit further investigation. / xiv leaves : ill. (some col.) ; 29 cm

Master of Science

As part of a large study aimed at searching for patterns of diversity in the genus Persephonella along the north to south geochemical gradient of the ELSC, ten novel strains of Alphaproteobacteria were isolated unexpectedly. Using defined media under microaerophilic conditions to enrich for Persephonella from chimney samples collected at the seven vent fields on the ELSC and the dilution to extinction by serial dilution method to purify cultures, a total of ten strains belonging to the Alphaproteobacteria were isolated. Two of these isolates, designate MN-5 and TC-2 were chosen for further characterization and are proposed as two new species of a novel genus to be namedThermopetrobacter. Both strains are aerobic, capable of chemoautotrophic growth on hydrogen and grow best at 55°C, pH 6 and 3.0% NaCl. Strain MN-5 is capable of heterotrophic growth on pyruvate and malate and TC-2 is only able to grow heterotrophically with pyruvate. The GC content of MN-5 is 69.1 and TC-2 is 67 mol%. GenBank BLAST results from the 16S rRNA gene reveal the most closely related sequence to MN-5 is 90% similar and the most closely related sequence to strain TC-2 is 89% similar. Sampling at a shallow marine vent on the coast of Vulcano Island, Italy in 2007 led to the isolation of a novel species of Hydrogenothermus, a genus within the Hydrogenothermaceae family. This isolate, designated NV1, represents the secondHydrogenothermusisolated from a shallow marine vent. NV1 cells are rod-shaped, approximately 1.5μm long and 0.7μm wide, motile by means of a polar flagellum and grow singularly or in short chains. Cells grow chemoautotrophically using hydrogen or thiosulfate as electron donors and oxygen as the sole electron acceptor. Growth was observed between 45 and 75°C with an optimum of 65°C (doubling time 140 min), pH 4.0-6.5 and requires NaCl (0.5-6.0% w/v). The G+C content of total DNA is 32 mol%.