Publication Date


Document Type


First Advisor

Starzyk, Marvin J.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Thermophilic bacteria; Plasmids; Thermus aquaticus


Plasmid analysis by the rapid alkaline method of plasmid DNA removal was performed on cultures of Thermus aquaticus YT1. Upon electrophoresis of the sample on an agarose gel, four plasmid bands were visualized. When measured against standard plasmids in coli V517, the molecular weights were estimated at 5.7, 8.9, 10.4 and 11.5 megadaltons. After electrophoresis, plasmid-ethidium bromide complexes were subjected to ultraviolet light and run in a second dimension to confirm that indeed the bands were covalently closed circle DMA. Molecular weights determined by contour measurements of spread DMA by an electron microscope corroborate with findings by agarose gel electrophoresis. Densitometer readings from negatives of gels provided a relative copy number in a ratio of 2:1 :1 :1 of the four plasmids, pTA1 through pTA4, respectively. Comparison with plasmids of Thermus species already established in literature and with environmental isolates showed that these species do not contain the same plasmids. However, laboratory strains of Thermus aquaticus, deviant by pigmentation or by high production of rotund bodies, produced similar banding patterns to that of the parent strain, indicating pigmentation and rotund body formation are characteristics probably coded for by chromosomal rather than plasmid DNA. Analysis of restriction endonuclease digests coincided with predicted results for DNA with a high guanine plus cytosine ratio.


Bibliography: pages [76]-81.


81 pages




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