Climate Science Program

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Larry Halverson

Associate Professor



Office: 351 Bessey

Phone: 515-294-0495









Department: Plant Pathology and Microbiology

Research Interests: genomics, bioinformatics

Brief description of current research:

My research group focuses on how water deprivation (low moisture contents, high salinity) influences biofilm growth and development, and survival (fitness), and the diversity of bacteria in residing in soil or in association with plants. Various environmental factors such as water content, salinity, temperature, nutrient availability, and the presence of organic and inorganic pollutants can strongly influence their metabolism, behaviors, and ecological competence (fitness) in soil environments. Our approach is to initially establish models systems for elucidating relationships between physiological, biochemical, and genetic responses bacteria employ to counter the detrimental effect those stresses impose on them. Consequently, it is essential to understand how those stresses affect bacteria to understand why certain behaviors are exploited to adapt to that stress. We scale-up the complexity of the systems to better reflect natural habitat conditions or examine those behaviors in soil systems. Ultimately, knowledge of microbial physiology provides a framework to better understand their ecological competence, and possibly how to manipulate and enhance their behaviors for beneficial purposes such as for detecting pollutant contamination, cleaning-up polluted soils, controlling of plant diseases, or promoting plant growth.

Recent publications:

Van de Mortel, M., and L. J. Halverson, 2004: Cell envelope constituents contributing to biofilm growth and survival of Pseudomonas putida in low-water-content habitats. Mol. Microbiol., 52, 735-750.

Chang, W. S., and L. J. Halverson, 2003: Reduced water availability influences the dynamics, development and ultrastructural properties of Pseudomonas putida biofilms. J. Bacteriology, 185, 6199-6204.

Cassavant, N. C., D. L. Thompson, G. A. Beattie, G. J. Phillips, and L. J. Halverson, 2003: Use of a site-specific recombination-based biosensor system for detecting bioavailable toluene and related compounds on plant roots. Environ. Microbiol., 5, 238-249.