Diversity and Ecology of Bdellovibrios-like Organisms in Nature

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The goal of this project is to determine the range in diversity and role of the bdellovibrio-like organisms (BLOs) in aquatic environments. Our specific aims are: 1) to reveal and characterize the genetic, cultural and physiological diversity of the predatory, bdellovibrio?like organisms (BLOs) in nature and to show a correlation between strain diversity and prey range; 2) to reveal the predominant uncultured and cultured strains of BLO, those most likely making the greatest contribution to bacterial mortality in nature, and show their spatial and temporal distribution in aquatic ecosystems; and 3) to monitor the population dynamics of BLO in phytoplankton/ bacterial blooms and assess their potential role in bacterial mortality. Genetic diversity will be analyzed for both cultured and uncultured BLOs. The initial effort will be to complete the diversity analysis on the 50 strains currently in the laboratory that have been recovered from water samples collected from lakes, oceans, seas, ponds and streams in the United States and abroad. Samples will be processed to detect both cultured and uncultured BLOs. The uncultured organisms will be identified by using molecular techniques employing BLO?specific oligonucleotide probes. The cultured strains will be recovered using the double agar overlay technique. In particular, we will sample to determine the potential interaction of the BLO community with phytoplankton blooms at the LEO? 15 site (a Long?Term Ecosystem Observatory site on the continental shelf offshore from the Rutgers University Marine Field Station) during upwelling-stimulated blooms. This work will be done in collaboration with Dr. Lee Kerkhof at the Institute of Marine and Coastal Sciences at Rutgers, the State University of New Jersey.