Research Interests

The main focus of my research examines extremophiles such as the moderately halophilic eubacteria and the extremely halophilic archaea. These types of microorganisms are often found in environments such as hypersaline lakes and salterns. The existence of such profuse life at high salt concentrations leads to the question of how these organisms are able to respond to and survive the various stresses they encounter in this situation. The first moderate halophile Halomonas elongata (ATCC 33173) was was originally isolated by this laboratory from a solar salt facility located on Bonaire, Netherlands Antilles. Previous work with this organism has examined growth parameters, compatible solutes, enzyme activity, transport, lipopolysaccharide and the effects of UV radiation. At this juncture the research involving UV radiation has been extended to a range of gram-negative and gram-positive moderate halophiles, and selected extreme halophiles.

Another focus of my laboratory involves the cyanobacteria such as members of the genus Synechococcus and the cyanophages (e.g. viruses) which infect them. A current project involves the effect of UV radiation on selected marine Synechococcus strains both in the laboratory and on naturally occurring marine samples.

Recent Publications

• Sheldon, J.L., T.A. Kokjohn, and E.L. Martin. The effects of salt concentration and growth phase on MRSA solar and germicidal ultraviolet radiation resistance. Ostomy/Wound Management 51: (1):28-37, 2005.
• The effects of ultraviolet radiation on the gram-positive marine bacterium Microbacterium maritypicum. P.D. William, S.L. Eichstadt, T.A. Kokjohn and E.L. Martin. Curr. Microbiol. In press.
• Perlman, A.M., J.K. Wolfe, T.E. Bush, J.K. Dyer, and E.L. Martin. Adenine toxicity and transport in the moderately halophilic eubacterium Halomonas elongata. J. Basic Microbiol. 41:97-104, 2001.
• Shaffer, J.J., L.M. Jacobsen, J.O. Schrader, K.W. Lee, E.L. Martin and T.A. Kokjohn. Characterization of Pseudomonas aeruginosa bacteriophage UNL-1, a bacterial virus with a novel UV-A inducible DNA damage reactivation phenotype. Appl. Environ. Microbiol. 65:2606-2613, 1999.