Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted. Errata sheet inserted.

Thesis (doctoral)--University of Göteborg, 1987. / Extra t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 101-109). Also available on the World Wide Web.

Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted. Errata sheet inserted.

No description available.

Violacein is a purple pigment typically produced by species of Chromobacterium and Janthinobacterium. A soil isolate, identified as Janthinobacterium, was studied. Maximal pigmentation occurred at 250C under aerobic conditions in the Keeble and Cross medium. Intracellular pigment was shown to be located in the cell membrane. Comparision of pigment production and growth curves indicated that violacein is synthesized in the cell and released into the environment possibly as a result of cell lysis. Extracellular pigment is water soluble, makes up 60% of the total pigment and shows a blue shift when compared to solvent extracted pigment. Results from purification indicated that the pigment is non-covalently bound to a small protein and aggregated into a larger molecule.

LD2668 .T4 1954 H8 / Master of Science

Helix hand inversion exhibited by Bacillus subtilis macrofibers is induced by changes in culture medium composition. The kinetics of this inversion are compared to those of temperature-induced inversions. D-alanine evokes a similar inversion process. The role of left-twist proteins(s), the existence of "memory", and the asymmetry of left to right versus right to left kinetics are confirmed within the context of these inversion regimes. Initiation time of right to left inversions is correlated to degree of pre-shift twist. Evidence is presented suggesting effective twist of the wall is defined by (1) the average of that twist conformation inserted prior to a shift in culture conditions and that of wall inserted following the shift and (2) the location of left-handed material within the wall. A constant 50 minute delay is observed before initiation of left to right inversions, irregardless of twist. Evidence is presented for a protein in the left to right inversion process. A classification system of macrofiber phenotypes based upon hand and degree of structural organization has been established. Three major classes are identified. Subclasses are shown to be distinguishable. Isotwist phenotypes of seven strains are defined upon a matrix of temperature and medium composition. These plots reveal a fundamental pattern of hand and organization that is present in each of the strains studied. The polarity of the four axes, the range of attainable twist conformations, and the existence of a right-hand maximum in the 12.5% SPl domain remain virtually constant. Major variations include extent of a disorganized band and/or the shifting of conformational range either left or right. Several mutants were transformed into A734, a strain that produces the tightest structures at all four matrix corners. Multiple mutations are responsible for the phenotypes of several strains. Evidence is presented for single genes that express as extreme left-handedness and stress at high temperature, swelling and stress in TB at high temperature, and reduction in structural organization produced in high TB content at low temperature.

No description available.

Pathogenic bacteria colonise their host animals by means of a complex set of interactions. The host defensive mechanisms attack foreign microorganisms and attempt to rid the animal of the invaders, while the bacteria express a variety of functions to ensure their survival under adverse conditions, some of which damage the host and cause the clinical symptoms of disease. Adhesins are the bacterial structures which mediate adherence to specific host tissues and therefore permit the colonisation of areas from which the bacteria would normally be removed. T4. I have genetically cloned and analysed an adhesin from a pathogenic strain of Escherichia coli isolated from a child with enteritis. The genetic information was transferred to laboratory strains of E. coli and was expressed under similar conditions as in the parent strain, generating material with the same adherence and antigenic properties. Thus, the cloned genes enabled laboratory strains to adhere to human colon, but not to duodenum, in the same manner as the parent. This probably accounts in large part for the tissue specificity of the pathogen which caused dysentery-like symptoms consistent with colonisation of, and damage to, the colon. The cloned genes encoded the synthesis of the adhesin as fine fibrils ('fimbriae') on the bacterial surface, approximately 2 nm in diameter. The 14,000 dalton protein subunits were assembled into very high molecular weight aggregates and were purified by size fractionation. The genetic determinant occupied about 6,000 basepairs of DNA, indicating a system of genes for the synthesis, export and assembly of functional adhesin. The genetic map was very similar to those of adhesins from another enteritis isolate and a urinary tract pathogen, suggesting an evolutionary relationship between these E. coli strains. However, the protein subunits of the three adhesins appear to differ, indicating a degree of divergence.