Microbiology 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 …

Quantitative Studies On Nodulation Competition Of Two Strains Of Bradyrhizobium Japonicum And Its Biological Control With A Bacteriophage, Jin Xiong

Masters Theses

Interstrain competition of Bradyrhizobium japonicum for nodulation of soybean (Glycine max) presents a serious problem to the field commercial inoculation practice. The more efficient, introduced strains are often outcompeted by the less efficient, indigenous strains. This study was conducted to determine if the competition could be effectively controlled by the massive introduction of a more efficient strain and/or the large scale reduction of a indigenous strain by the application of a bacteriophage specific to the indigenous one.

B. japonicum strain 61A123, common in Midwestern U.S. soils, and strain USDA110, representative of the strains used in commercial inocula, were chosen for …