Typescript (photocopy). / Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

In the present research, nicotine alkaloid production by Nicotiana tabacum (tobacco) hairy roots and tropane alkaloid production by Hyoscyamus niger hairy roots were investigated. The first objective of this research was to improve the oxygen mass transfer in hairy root cultures with microbubbles. Oxygen was shown as a critical nutrient for the growth of tobacco and H. niger hairy roots. In a 1-liter fermentor, microbubble dispersion improved the oxygen mass transfer, tobacco hairy root growth, and nicotine production in the medium. In a novel ground-joint column bioreactor, microbubbles enhanced the oxygen mass transfer and the growth of H. niger hairy roots. The second objective of this research was to enhance the release of alkaloids from the hairy roots into the culture medium. In a l-liter fermentor, nicotine concentration in medium was improved by adjusting the medium pH to 6. Unlike the nicotine alkaloid, hyoscyamine concentration in medium was not detectable at medium pH 6, whereas hyoscyamine in medium increased to 42 mg l-1 at medium pH 3. Similar to the hyoscyamine, scopolamine in medium increased from 0.1 to 11 mg l-1 when the medium pH was adjusted from 6 to 3. The release of alkaloids into culture medium provides opportunities to isolate a high-value alkaloid directly from the culture fluid, and reduces the cost of product recovery.

The technology of modern fermented milk production is not complicated and relies largely on the characteristics of the microorganisms used in its manufacture. Biochemical substances excreted by the starter cultures contribute to the chemical, physical and organoleptic properties of cultured milks. Chemical and organoleptic properties of yoghurt starter cultures have been widely studied over several decades. Conversely the biosynthetic processes and genetic control of the production of viscous extracellular material (slime) by selected thermophillic streptococci is still insufficiently understood. This study attempted to elucidate physiological aspects and the genetic control of slime production. An attempt to chemically induce ropiness was also preformed. Twenty strains of Gram positive, thermo-tolerant, milk dotting, catalase negative cocci were collected from a variety of sources. All strains were identified as Streptococcus thermophilus. Four of the isolates were identified as capable of producing an extracellular, ‘ropy’ capsular material. A negative staining method for highlighting capsular material under light microscopy was described. Ropy isolates displayed thick capsular zones of between 6-8 μm. The isolates graded as non-ropy produced only small capsular zones (less than 2 μm); two variants displayed no capsular material. Instability of the ropy phenotype during subculture and prolonged storage was described for all four ropy isolates at varied temperatures. Instability during transfer was reported as moderate with a loss of no more than 45% of ropy colonies after 15 subcultures at 48°C A significant increase in instability, during transfer, associated with an increase in incubation temperature (37-48°C) was also reported. Prolonged storage of ropy variants over ten days resulted in a drop in the number of ropy colonies. The loss was minimal when cultures were stored at 8°C, but excessive (approaching 100%) at 37°C This suggested the presence of capsular degradative substances. Analysis of the plasmid profiles of 20 strains identified only two strains harboured plasmid DNA. All plasmids were small, less than 23kilobases, and each strain possessed a single plasmid species. Only one ropy strain contained plasmid DNA that was shown, with the aid of curing experiments, not to be linked to production of the ropy phenotype. The amino acid analogue p-fluoro-DL-phenylalanine was unsuccessful in generating ropy colonies from non-ropy variants of Streptococcus thermophilus at low concentrations. Some technological considerations for the use of ropy variants of Streptococcus thermophilus in yoghurt starter cultures were made.

Coming Through, a novel based on factual events, explores elements of the alternative sub-culture in Australia in the period between 1959 and 1980. Dual protagonists, Anna Martin and Jack Rose, personify aspects of the movement that would later be known as 'psychedelic romanticism.' The narrative follows Jack Rose's disenchantment with the prevailing social system and his efforts to achieve personal integration and his conflict with societal pressures to conform. Likewise, in a parallel narrative, it describes the events that surround Anna Martin's early institutionalisation and her attempt to achieve personal authenticity. When the protagonists finally encounter one another they find that a common and binding philosophy has drawn them together. The thesis looks at the prevailing social notions of'normality' at the time and the problems associated with alienation and the struggle to found alternative life styles in a society they deem to be repressive.

No description available.

No description available.

Research on natural environments, over the last decade, is replete with microbial diversity studies that used culture-independent approaches. The cloning and sequencing of the 16S rRNA genes has been the driving force in the expansion of awareness about the great diversity of previously undiscovered microorganisms. Well-known uncultured groups of microorganisms are numerous, and half of the known phylogenetic divisions of bacteria are not represented in any culture collection. It is no longer assumed that cultures acquired from an environment represent the dominant or physiologically important organisms from that environment. A high throughput culturing (HTC) technique was developed in an attempt to bring into culture some of these widespread and uncultured microorganisms. Over the course of 3 years, 2,484 culturing attempts were screened for microbial growth from sample collections off the coast of Oregon and 576 attempts from groundwater at McClellan Air Force Base (MAFB). However, using the HTC approach up to 14% of the microorganisms counted by direct microscopy were cultured. In contrast, less than 1% of the microorganisms from natural environments that are observed under a microscope can be grown using standard agar plating techniques. This newly developed technique was successful at bringing into culture 11 previously uncultured or undescribed Proteobacteria. Four were isolated from the marine environment including, members of the SAR11 clade (alpha subclass), OM43 (beta-subclass), SAR92 (gamma subclass), and OM60/OM241 (gamma subclass). SAR11 was transiently cultured in this study but was later successfully brought into culture using these HTC techniques by Mike Rapp��. Eight were isolated from a trichioroethene (TCE) and cis-dichloroethene (cis-DCE) contaminated aquifer, including members of the MHP14 clade (alpha subclass), 4-Org1-14 dade (alpha subclass), Herbaspirillum/Oxalobacter clade (beta subclass), HTCC333 (beta subclass), HTCC410 (beta subclass), PM1 clade (beta subclass), Boom-7m-04 clade (beta subclass) and OM43 clade (beta subclass). Culturing microorganisms is an important step towards understanding their physiology and ecology, and in most cases is necessary for the formal systematic description of a new species. For microorganisms of global significance, such as the major uncultured bacterioplankton and soil microbiota, obtaining cultures is a prerequisite for obtaining complete genome sequences and understanding the relevance of these microorganisms to biogeochemical cycles. / Graduation date: 2003

Graduation date: 1999

Graduation date: 1997