Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment


Plant and Soil Sciences

First Advisor

Dr. Luke Moe


Several bacteria isolated from the broccoli rhizosphere were assayed to compare their ability to solubilize phosphate and release pyrroloquinoline quinone (PQQ) into the surrounding media. Subsequently, their genomes were sequenced and analyzed for PQQ biosynthesis operon structure. PQQ biosynthesis genes pqqA-F were found in all isolates. The order of PQQ biosynthesis genes and predicted amino acid sequences were compared to each other and the host’s ability to solubilize phosphate and release PQQ. In all Pseudomonas species, two putative protease genes, pqqF, and pqqG, flanked the canonical pqqA-pqqE biosynthesis operon. No mechanistic studies have confirmed the function of pqqF and pqqG.

Pseudomonas putida KT2440 is a versatile model organism, representing environmental, agronomical, and industrial interests. Like the broccoli isolates, P. putida KT2440 biosynthesizes and releases PQQ into its surroundings. To better understand their functions within PQQ synthesis in P. putida KT2440, ∆pqqF, ∆pqqG, and ∆pqqF/∆pqqG strains of P. putida KT2440 were generated and the resulting phenotypes were studied.

Digital Object Identifier (DOI)