Aquatic Sciences Meeting, Albuquerque 2001

PC16 Microbial Dynamics

Date: Thursday, February 15, 2001

Location: Southwest Hall

Howard-Jones, M, H, Skidaway Institute of Oceanography, Savannah, USA, hhjones@skio.peachnet.edu

Ballard, V, D, Savannah State University, Savannah, USA, vdb_79@hotmail.com

Williams, S, C, Skidaway Institute of Oceanography, Savannah, USA, sam@skio.peachnet.edu

Hristov, R, , Skidaway Institute of Oceanography, Savannah, USA, ruslan@skio.peachnet.edu

Verity, P, G, Skidaway Institute of Oceanography, Savannah, USA, peter@skio.peachnet.edu

Frischer, M, E, Skidaway Institute of Oceanography, Savannah, USA, frischer@skio.peachnet.edu

DISTINGUISHING BETWEEN LIVING, NON-LIVING, AND INACTIVE CELLS IN THE MARINE ENVIRONMENT

The variability and dynamics of living, non-living, and inactive cells was examined in two diverse marine environments. The vital stain and probe (VSP) method was used to simultaneously evaluate samples for staining with DAPI, propidium iodide, and hybridization with 16S rRNA oligonucleotide probes. Samples were also evaluated for staining with CTC, and radiolabeling of amino acids. Low activity cells consistently make up 40-50% of the total cells, while dead but recently active cells are low (< 10%), regardless of the environment. In SAB samples, active cells (determined by CTC, probes, Leucine) are more abundant in inshore waters. Only a small fraction of the cells stain with CTC (4-12%), however a larger fraction hybridize with probes (25-55%). Samples from Norway indicate that active cells are greatest in the polar front and ice melt, while inactive cells are significant in all samples (20-70%). Combined, these observations suggest that inactive cells dominate marine bacterioplankton and the proportion of active cells fluctuate considerably. This study supports the hypothesis that natural environments are composed of dynamic populations that express varying levels of growth and activity.

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Aquatic Sciences Meeting, Albuquerque 2001

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