Martino, D. P. Princeton University, martino@geo.princeton.edu
Ward, B. P. Princeton University, bbw@geo.princeton.edu

 
DIVERSITY OF DENITRIFYING BACTERIA FROM TOMALES BAY, CA, BASED ON RIBOSOMAL AND NITRITE REDUCTASE GENE SEQUENCES
 
Diversity in ribosomal and functional genes of known strains and marine sediment isolates of denitrifying bacteria was investigated using the PCR and DNA sequence analysis. Denitrification, a respiratory process in which nitrogenous oxides serve as terminal electron acceptors for heterotrophic bacteria in the absence of O2, serves as the major sink for fixed nitrogen in aquatic as well as terrestrial ecosystems. The ability to respire nitrate is widespread throughout bacterial divisions but the ability to respire nitrite is more restricted; therefore we wished to investrigate the relationship between phylogenetic (ribosomal) diversity and functional gene (nitrite reductase) diversity in denitrifiers. The nitrite reductase (NiR) gene was characterized by the use of two primers sets specific for the heme cd1 type NiR gene. Several unique marine sediment NiR sequences (~ 750 bp) were analyzed. Several marine NiR genes clustered closely with organisms from the genus Pseudomonas, the most commonly isolated denitrifying genus, but functional gene diversity was much greater than 16s rRNA gene diversity for cultures as well as environmental isolates. Most of the ribosomal sequences grouped with the genera Pseudomonas or Vibrio.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: CS55TH0468S