The Effect of Leucine, Isoleucine, and Valine on the Growth of Agrobacterium tumefaciens C58 (2013)

Undergraduates: Kristina Stanson, Adriana Beltran Jennifer Rominger, Patrick Edmundson

Faculty Advisor: Ann Matthysse
Department: Biology

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The superpathway of valine, leucine, and isoleucine biosynthesis in Agrobacterium tumefaciens is an extensive pathway involving multiple genes in multiple operons that affect the growth and morphology of A. tumefaciens C58. In order to determine how these three branched-chain amino acids altered the growth of Agrobacterium tumefaciens, we prepared plasmid E. Coli DNA containing the transposon pRL27 and introduced it into competent A. tumefaciens. After selecting for those bacteria which in fact up took the plasmid and its transposon, we screened for mutants in which the transposon affected genes involved with the biosynthesis of leucine, isoleucine, and valine. Subsequently, we screened for mutants that were affected individually by the biosynthesis of a single amino acid. Valine was found to inhibit growth the least, followed by leucine and isoleucine, with isoleucine showing markedly smaller colonies.