Degree Name

MS (Master of Science)

Program

Biology

Date of Award

12-2008

Committee Chair or Co-Chairs

Ranjan N. Chakraborty

Committee Members

Dhirena Kumar, Bert C. Lampson

Abstract

Iron is the 4th most abundant metal on the earth's crust and is required by most organisms as a cofactor for many enzymes; however, at physiological pH and aerobic conditions iron forms insoluble ferric oxyhydroxide polymers. Siderophores are low molecular weight compounds that scavenge ferric ions, bind with high affinity, and transport it into the cell via multicomponent transport systems. Rhizobia are soil dwelling organisms that form symbiotic relationships with host plants and fix atmospheric nitrogen, while the bacteria receive nutrients. R. leguminosarum IARI 917 produces a siderophore characterized as 'schizokinen'. In the present study, we have characterized the binding and transport kinetics of 'schizokinen' and have also attempted to identify the genes involved in its biosynthesis using mini Tn5 random mutagenesis. DNA sequence analysis of a non siderophore producing transconjugant revealed a gene involved in PAC/PAS signal transduction systems that respond to many extracellular cues.

Document Type

Thesis - unrestricted

Copyright

Copyright by the authors.

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