STRENGTHS AND LIMITATIONS OF PROPOSED RESEARCH 



The expected data will directly assess the proportion of growing versus nongrowing gram 

 negative bacterioplankton in the Hatteras collection site during the two sampling periods e.g. 

 March and June '94. In conjunction with Dr. Giovannoni's data analysis on rRNA/rDNA we 

 should also be able to comment on the most important taxa contributing to changing biomass. 



STATUS OF RESEARCH 



Pilot batch sample analysis has been completed using Pacific (OR) coastal water samples. 

 DnaK protein was successfully detected in these samples and quantitated by transmittance 

 densitometry of Western blots probed with an anti-DnaK monoclonal antibody. These data were 

 normalized to total protein to assess the growth state of the bulk cell population. In addition, 

 Hatteras samples have been collected (March '94 cruise) and are currently undergoing analysis. 



Extension of these methods will focus on the analysis of individual cells as a means of 

 refining "bulk" sample data. Significant effort is being devoted towards the development of 

 single cell analytical techniques for DnaK quantitation which will be crucial for determining the 

 contribution of individual dominant bacterioplankton taxa to carbon respiration. 



Keywords: microbial, growth rates, DNAK, protein 



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