bacterioplankton taxa. Other methods, based on microscopic visualization of single cells, are 

 under development in collaboration with Drs. Paul Kemp and Paul Blum. 



STRENGTHS AND LIMITATIONS OF PROPOSED RESEARCH 



The strength of this approach is the ability to measure significant elements of community 

 structure which were previously unknown. The main limitation is that current methods are 

 time-consuming. However, the pace of new developments is quick, with both the speed and 

 accuracy of methods increasing. 



STATUS OF RESEARCH 



Members of the bacterial group, the "SAR11 cluster", have been identified in samples 

 collected at the OMP study site. A suite of probes specific for the SAR11 cluster have been 

 designed and tested. A 16S rDNA clone library ( > 100 clones) prepared from Cape Hatteras 

 bacterioplankton assemblages is being screened to identify additional bacterioplankton taxa. The 

 most abundant of these taxa will become the focus of probe development and future study. In 

 May, 1994, over 100 samples were collected at the study site (in triplicate). These samples will 

 be used to verify the numerical importance of dominant bacterioplankton, and to test the 

 reproducibility of methods. 



Keywords: microbial, taxonomy, rRNA, rDNA, vertical stratification 



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