PRINCIPAL 

 INVESTIGATOR(S) 



Sallie W. Chisholm 



Ralph M. Parsons Laboratory 



Department of Civil and Environmental Engineering 



Massachusetts Institute of Technology 



Cambridge, MA 02139 



Brian Binder 

 Institute of Ecology 

 The University of Georgia 

 Athens, GA 30602-2206 



PROJECT TITLE 



MEASUREMENT OF SYNECHOCOCCUS IN SITU GROWTH 

 RATES USING FLOW CYTOMETRY AND rRNA- 

 TARGETED PROBES 



AMOUNT OF FUNDING FY 1994: $128 K 



SUMMARY OF GOALS 



The ultimate goal of this project is to gain an understanding of the factors regulating the 

 dynamics of picoplankton populations and the contribution of these populations to primary 

 productivity in coastal environments. To this end, we are developing methods for the 

 measurement of Synechococcus growth rates in the field, free from the potential artifacts 

 associated with bottle incubations. Application of such measurements to coastal ecosystems 

 would greatly improve our understanding of the rate of primary production by this important 

 group of organisms, the role of different environmental factors in regulating this rate, and the 

 importance of grazing and other loss terms in the overall dynamics of these populations. 



Our immediate goals are: 



1- To establish protocols for the preservation and flow cytometric analysis of DNA, rRNA, and 

 protein in individual Synechococcus cells. 



2- To establish the relationship between these biochemical parameters and growth rate under a 

 range of environmental conditions, and among a variety of Synechococcus strains. 



3- To test these protocols and relationships in the field by comparing the results with more 

 traditional measures of growth rate and primary productivity. 



4- To use the method to measure in situ Synechococcus growth rates in coastal ecosystems. 



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