Loyola University Maryland

Department of Biology

schoeffield

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As a microbial ecologist, I am extremely interested in the roles of bacteria in aquatic ecosystems; how bacterial populations are interacting with one another, and how their interactions with one another effect the ecosystem as well as other organisms within that ecosystem. Specifically, I am interested in the ecological roles of a unique group of bacteria that prey upon other bacteria, collectively known as bdellovibrios. Our lab has recently demonstrated bdellevibrios ability to prey on bacteria existing in a very different physiological state common in aquatic ecosystems, a sort of "hibernating form" of the prey that we refer to as a viable-non-culturable state. This is significant because it has been shown that pathogenic (disease causing) bacteria in a viable-non-culturable state can still cause human disease. Our research team here at Loyola has also been involved in understanding the interaction of bdellovibrios ability to 1) associate with and become a member of the biofilm community, 2) prey upon susceptible members of the community, and 3) reduce the number of attached prey bacteria. Because the role of biofilms range from extremely useful (they may function to cleanse water), to very harmful (they accumulate toxic compounds and recruit oyster larvae to cement themselves on these "toxin-contaminated" surfaces), the effects of bdellovibrios on biofilms may have far reaching consequences. Understanding these consequences is a major thrust of my current work and we are now assessing the effect of bdellovibrios on insecticide-contaminated biofilms.

 

Selected Publications

 

Schoeffield, A.J. and H.N. Williams (1990) Efficiencies of recovery of bdellovibrios from brackish-water environments by using various bacterial species as prey. Applied and Environmental Microbiology 56: 230-236.

Schoeffield, A.J., W.A. Falkler Jr., D. Desai, and H.N. Williams (1991) Serogrouping of halophilic bdellovibrios from Chesapeake Bay and environs by immunodiffusion and immunoelectrophoresis. Applied and Environmental Microbiology 57: 3470-3475.

Williams, H.N., A.J. Schoeffield, D. Guether, J. Kelley, D. Shah, and W.A. Falkler Jr. (1995) Recovery of bdellevibrios from submerged surfaces and other aquatic habitats. Microbial Ecology 29: 39-48.

Schoeffield, A.J., H.N. Williams, B-F. Turng, and W.A. Falkler Jr. (1996) A comparison of the survival of intraperiplasmic and attack phase bdellevibrios to reduced oxygen. Microbial Ecology 32: 35-46.