PRINCIPAL 



INVESTIGATOR(S) F. Robert Tabita 



Department of Microbiology 

 Ohio State University 

 484 W 12th Ave 

 Columbus, OH 43210 



PROJECT TITLE REGULATION OF PHOTOS YNTHETIC CARBON FIXATION 



ON THE OCEAN MARGINS 



AMOUNT OF FUNDING FY 1994: $76 K 



SUMMARY OF GOALS 



The goals are to 1) understand regulation of ribulose bisphosphate carboxylase 

 (RubisCO) in phytoplankton cultures in response to light regime 2) determine regulation of 

 RubisCO in response to light during nutrient limitation in these cultures 3) to determine 

 mechanisms of RubisCO regulation in natural populations of phytoplankton on the ocean 

 margins in the Gulf of Mexico and 4) to measure regulation of RubisCO in phytoplankton of 

 the Hatteras System. Two goals are laboratory-based, and two are ship-based. 



During the first year, the Tabita lab is primarily responsible for objectives 1 and 2 of 

 the overall project (see above). Specifically, we have initiated experiments to probe the 

 regulation of RubisCO in response to different light and nutrient limitation conditions in 

 representative marine cyanobacteria and diatoms. These studies have been performed to 

 understand the factors that control RubisCO gene transcription and RubisCO activity, and to 

 relate these molecular perturbations to changes in the marine environment that influence 

 overall C0 2 and carbon metabolism. 



SPATIAL AND TEMPORAL SAMPLING SCALES 



Participation in DOE cruises is highly desired. We would be interested in spatial 

 sampling across the shelf in conjunction with the spring bloom at least 4 stations along a 

 transect (for vertical profiles). During a second cruise, diel regulation and regulation under 

 various light regimes is required for us to complete our DOE mission. These studies last 

 24-48 hr/diel with sampling every 4 hr. 



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