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Molecular Phylogenetic Analysis Of Magnetotactic Prokaryotes, Peter A. Eden

Doctoral Dissertations

Of the many diverse forms of magnetotactic bacteria found in nature, very few have been isolated in axenic culture. Consequently, it has not been possible to address by conventional microbiological techniques the extent of phylogenetic conservation of magnetotaxis among prokaryotes. Modern methods of DNA amplification combined with nucleotide sequence analysis were considered, at the inception of this study, to provide a means of addressing phylogenetic relatedness among magnetotactic bacteria in the absence of axenic cultures. Analysis was made of the 16S ribosomal RNA of Aquaspirillum magnetotacticum strain MS1 and Bilophococcus magnetotacticus, to initiate phylogenetic characterization of magnetotactic organisms. These freshwater …

Expression Of The Murine Ornithine Decarboxylase Gene In Transgenic Nicotiana Tabacum Var Xanthi, Richard Anthony Descenzo

Doctoral Dissertations

Ornithine decarboxylase (ODC), arginine decarboxylase (ADC), and S-adenosyl-methionine decarboxylase (SAMDC) are the three key regulatory enzymes for polyamine (putrescine, spermidine, and spermine) biosynthesis. In order to gain more insight into the relationship between polyamine metabolism and other physiological processes, research was undertaken to obtain increased putrescine biosynthesis in tobacco by overexpression of a murine ODC cDNA.

Both a full-length and a truncated murine ODC cDNA were cloned into a binary expression vector containing the Cauliflower Mosaic Virus (CaMV) 35S promoter. Using standard leaf-disc transformation procedures, transgenic tobacco plants containing either the full length or the truncated ODC cDNA were obtained. …

Genetic Transformation Of Industrial Species Of Bacillus And Clostridium, Gregory Andrew Birrer

Doctoral Dissertations

The relationship between growth rate and competence for genetic transformation in B. subtilis 168 was investigated. B. subtilis grown in chemostat cultures expressed competence at a relatively rapid growth rate of 2.5 h (mass doubling time, t$\sb{\rm d}$). Since the literature suggested competence normally occurred at slower growth rates in batch cultures, B. subtilis was grown in a biomass recycling fermentor and extremely slow growth rates were examined for the expression of competence under carbon/energy limitation. No additional peaks on the number of competent cells were detected. However, major metabolic manifestations were observed at the growth rate where competence is …

Molecular Variation In Picea Rubens And Picea Mariana, Michael S. Bobola

Doctoral Dissertations

Restriction fragment length polymorphism (RFLP) variation was examined among samples from the entire range of red spruce (Picea rubens Sarg.), the eastern complex of black spruce (Picea mariana (Mill.) B.S.P.), control-cross red-on-black hybrids, and natural populations of red and black spruce. Within-species and population variation was examined. In addition an accurate species index capable of identifying red spruce, black spruce and hybridization between the two species was developed.

The nuclear rDNA repeat unit size in Picea ranged from a minimum of 32 kbp to greater than 40 kbp, two to three fold larger than the typical angiosperm rDNA unit. At …