Antibiotic Regulation in the Biological Control Bacterium Pseudomonas fluorescens Strain Pf-5

EPA Grant Number: U915213
Title: Antibiotic Regulation in the Biological Control Bacterium Pseudomonas fluorescens Strain Pf-5
Investigators: Whistler, Cheryl A.
Institution: Oregon State University
EPA Project Officer: Lee, Sonja
Project Period: January 1, 1997 through January 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text |  Recipients Lists
Research Category: Fellowship - Molecular Biology/Genetics , Academic Fellowships , Biology/Life Sciences


The objective of this research project is to understand the regulation of antibiotic production in the biological control bacterium Pseudomonas fluorescens Pf-5. When applied to seeds, this bacterium produces several antibiotics, including pyoluteorin and 2,4-diacetylphloroglucinol, which protect seeds and roots from infection by fungal plant pathogens including Pythium ultimum. This research will aid in understanding how different environmental factors can influence antibiotic production by Pf-5 and the success of this bacterium as a biological control agent.


An existing collection of Tn5 insertion mutants of Pf-5 with altered antibiotic production profiles is being utilized to identify previously undescribed genes that regulate antibiotic production. The role of a gene in antibiotic regulation is confirmed through marker-exchange mutagenesis. Sequence analysis of a corresponding wild-type gene provides theoretical information of its identity and role in antibiotic regulation, as well as possible environmental factors that may influence regulation. Identification of regulatory genes aids in the understanding of regulatory pathways. Of particular interest to me is how different genes interact to influence antibiotic production, perhaps in regulatory cascades, and the role of stress response in antibiotic regulation. To date, three genes that regulate antibiotic production have been identified: GacA, GacS, and RpoS.

Supplemental Keywords:

fellowship, Tn5 insertion mutant, pyoluteorin, antibiotic production, Pseudomonas fluorescens, regulatory genes, Pythium ultimum, Pf-5, fungal plant pathogens., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, exploratory research environmental biology, Genetics, Ecosystem/Assessment/Indicators, Ecological Effects - Environmental Exposure & Risk, Biochemistry, Ecology and Ecosystems, Molecular Biology/Genetics, Biology, Ecological Indicators, molecular genetics, molecular ecology, antibacterial agents, environmental stress-responsive gene expression, fungal plant pathogens, gene-environment interaction, antibiotic production, genetic consequences, pseudomonas fluorescens, biological control agents

Progress and Final Reports:

  • 1997
  • 1998
  • Final