| Current Research Funding
"Do marine aggregates facilitate gene transfer of antibiotic resistance in nature?" (1 Jan 2009-30 Jun 2009), $81,782, Old Dominion University Seed-Money Grant. Co-PIs are Gary Schafran, Holly Gaff, Wayne Hynes, and Jin Wang, all at Old Dominion University.
"Effects of non-equilibrium plasma on eukaryotic cells" (1 Dec 2005-30 Nov 2008), $240,000, Air Force Office of Sponsored Research. Co-PI is Mounir Laroussi, Old Dominion University.
"Assessing, detecting, and managing the risks to the Great Lakes from non-indigenous microbes introduced by commercial ships" (15 Nov 2007-14 Nov 2009), $259,094, Great Lakes Protection Fund via Northeast-Midwest Institute.
Current Research Projects
My research collaborators and I have established four ongoing projects: a) microbial ecology of ships' ballast tanks; b) groundwater trophodynamics; c) microbial inventories of shallow-water sediments and their relationship to optical properties; d) "Bioelectrics". Although I have been Principal Investigator (PI) for most of the related funding, Dr. Lisa A. Drake and Dr. Martina A. Doblin have been co-PIs (and sometimes PI) on several grants with me.
Ballast-tank ecology is the largest of the four research programs. For a "popular science" overview of environmental and economic concerns with biological invasions mediated by ballast water, please see (http://www.epa.gov/owow/estuaries/coastlines/01apr.pdf). We are studying the presence, abundance, transport, and fate of microorganisms, including pathogens, in ballast tanks and are sampling not only water, but residual sediments and biofilms as well. In the latter half of 2001, I was on sabbatical at NOAA's Great Lakes Environmental Research Laboratory, where I extended my team's Chesapeake Bay operations to a multi-year study of ballast residuals in the Great Lakes (www.glerl.noaa.gov/pubs/brochures/nobob/nobob.pdf). Funding sources for ballast research include Maryland, Virginia, and National Sea Grant College Programs, NOAA, US Coast Guard, US Environmental Protection Agency, and the Great Lakes Protection Fund.
The transport of bacteria in groundwater is of great interest to the Department of Energy (DOE), as it is a process affecting the delivery of remediative bacteria to polluted subsurface horizons. At a nearby groundwater study site, DOE has created a multi-million dollar array of wells and multiple-level samplers and performs bacterial injection experiments. I hypothesized that following the injection of large numbers of bacteria, populations of groundwater protistan predators might well be stimulated. Indeed, our participation in injection experiments has shown a pronounced response, principally by flagellates. We have begun publishing the temporal and spatial dynamics of their response, as well as the implications of these predator-prey trophic interactions for groundwater carbon-biomass balances (Balkwill, D., et al. 2001. Breakthroughs in field-scale bacterial transport. EOS Trans. 82:417, 423-425 (and) Zhang, P., W.P. Johnson, T.D. Scheibe, K.-H. Choi, F.C. Dobbs, and B.J. Mailloux. 2001. Extended tailing of bacteria following breakthrough at the Narrow Channel focus area, Oyster, Virginia. Water Resour. Res. 37:2687-2698).
The Office of Naval Research has for more than five years supported a Coastal Benthic Optical Properties (CoBOP) program, with the ultimate intent of producing a working radiative-transfer model for sub-littoral environments. The model is to predict the inherent optical properties of selected benthic environments given input from physics, geochemistry, sedimentology, and microbiology. In the context of the last, we have investigated the biomass and membrane-lipid biomarkers of microbial communities associated with sediments and seagrass. Our rationale is that light must pass through a "microbial gateway" before it reaches the sediment or seagrass and prior to its return to the water column. To understand time-and-space variations in optical parameters, therefore, we must understand the microbial milieu in which they exist. (For more about the CoBOP program, see http://www.psicorp.com/cobop/cobop.html).
The fourth research program, "Bioelectrics", is one conducted in collaboration with Prof. Karl Schoenbach and Dr. Mounir Laroussi, electrical engineers here at ODU. One program element involves application of electrical discharges having very high voltage (up to 50 kV) and very short duration (50 msec or less) to suspensions of cells. The intent is to irreversibly electroporate the cells' membranes and thereby kill them. There are potential applications in food, juice, and drug processing technologies, and in treatment of ships' ballast water. In addition to electrical experiments, we have tested the effects of excimer ultraviolet radiation on bacteria and dinoflagellates (funding from NOAA's ballast-water treatment program) and of atmospheric plasma (also called "cold plasma") on bacteria living on surfaces. In the future of the "Bioelectrics" program, we will seek to expand our crude perception of killing mechanisms to a more refined and predictable understanding of subcellular effects. |
