Science Serving Maryland's Coasts

Amanda (Klingensmith) Martino, Saint Francis University

Class Year: 

Project Title: 

Phylogenetic Screening of Ribosomal RNA Gene-Containing Clones in Fosmi Libraries from Chesapeake Bay Bacterioplankton


Bacteria are central players in many important processes within aquatic ecosystems, yet little is known about the diversity, distribution and precise functions of these organisms. This is due mainly to the difficulty in culturing these organisms in the laboratory. However, the application of molecular techniques to the field of marine microbiology is beginning to unveil the mysteries of bacterial roles in marine systems. The DNA of cells can be directly examined without need to grow the bacterial cells. In this study a fosmid library was created storing the genetic information of bacteria present in surface waters of the mid Chesapeake Bay. Partial analysis of the library via ITS-LH-PCR and limited sequencing has revealed some of the diversity of bacterioplankton in the bay. 60% of the bacterial groups identified belonged to the actinobacteria class, which was traditionally associated with freshwater bacteria only. 25% of the species identified belonged to the bacteroidetes phylum, 9% to the Roseobacter group and 6% to the gamma subclass of the proteobacteria phylum. Further analysis of the library may reveal a greater diversity of species and the genetic information stored could even be used for other purposes in the future such screening for genes of particular interest or searching for the presence of antibiotic-producing organisms.