Bacteriology Commons^™

Partial Characterization Of Lpss From Rhizobium Fredii Usda 205 Before And After Nod Gene Induction, Bradley Lawrence Reuhs

Masters Theses

The lipopolysaccharides (LPS) from Rhizobium fredii USDA 205 and its nod- mutant, HC 205, which has been cured of the 192-MDa symbiotic plasmid, were isolated by the phenol-water extraction method. The LPS from the wild-type strain which was grown in association with host-plant root extract or a flavone analog to a constituent of the root extract, which is required for the induction of at least a portion of the nodulation genes, was also isolated. The conditions required for the induction of the nod genes were determined by work with a nod- mutant of R. fredii USDA 201 which …

Restriction Analysis Of Bacteriophage, Ali Reza Mostaghimi

Loma Linda University Electronic Theses, Dissertations & Projects

A restriction map of DNA from bacteriophage P3-C₁ for the endonucleases BamH I, Bgl II, EcoR I, Hind III, Sac I and Sca I is described in this study. The phage DNA was determined to be a linear double stranded molecule with a unit genomic length of 31 kb. After electrophoresis in 0.5% agarose gels, the undigested DNA appeared as three molecules of 31, 62 and 93 kb in length. The Hind III digestion pattern of the individual 31 kb molecule was identical to the 62 kb and 93 kb Hind III pattern. With all enzymes except Hind III, …

A Comparison Of The Acidic Extracellular Polysaccharides From Rhizobium Trifolii Mutants Affected In Trifolium Repens Root Hair Curling, Brian Andrew Hanley

Masters Theses

The compositions and sugar linkages of the acidic extracellular polysaccharide (EPS) from several Rhizobium trifolii mutants were compared. These mutants were derived from a wild type Rhizobium trifolii, ANU843, and are unable to cause normal root hair curling, Hac-, or nodulate clover, Nod-. Three of the mutants contain a Tn5 insertion in a 5.3 kb BglII fragment of the symbiotic plasmid (pSym). A fourth mutant is missing the pSym, which includes much of the 5.3 kb BglII fragment, both of these deletions result in Hac-Nod- phenotypes. When the 5.3 kb BglII fragment is cloned (pRT150) and reinserted into the …

Cole1 Copy Number Mutants., Londa Schmidt, Joseph Inselburg

Dartmouth Scholarship

A deletion mutant of the colicin E1-derived plasmid, pDMS6642, exhibited an approximately fourfold increase in copy number. We subsequently isolated hydroxylamine-induced mutants of that plasmid that had a further increase in copy number. Analysis of them suggests that the increased copy number of pDMS6642 is associated with transcriptional readthrough from a Tn3 transposon into the region of ColE1 containing information that influences plasmid replication. The hydroxylamine mutation in one copy number mutant appeared to increase the plasmid copy number by stimulating readthrough transcription from the Tn3 transposon into the ColE1 replication control region, whereas the other hydroxylamine mutation acts by …

Biochemical Properties Of Salmonella Potsdam Bacteriophage P4/2, Clyde L. Roggenkamp

Loma Linda University Electronic Theses, Dissertations & Projects

Over 90% recovery of phage P4/2 was realized with differential centrifugation concentration and purification, whereas only about 16% was recovered from the aqueous two-phase polymer - Genetron - ECTEOLA-cellulose column system. Purity of preparations was greatest with the density gradient centrifugation (A₂₆₀ = 2.66 and A₂₈₀ = 1.80 per 10¹² plaque-forming units). With the chemical system of concentration and purification followed by an ECTEOLA anion exchange run, the A₂₆₀ was 6.6 and the A₂₈₀ was 4.3.

Three tests were employed to determine the configuration of P4/2 DNA: (1) a formalin denaturation test, (2) a thermal …