Wommack, K. University of Georgia, ewommack@arches.uga.edu
Chen, F. University of Georgia,
Hodson, R. E. University of Georgia, rhodson@arches.uga.edu

It is now believed that nitrogen fixation by marine prokaryotes may provide an important source of nitrogen in marine ecosystems. Besides the well studied filamentous cyanobacteria Trichodesmium, a taxonomically diverse range of marine bacteria have been shown recently to posses genetic elements homologus to nifH, which encodes the iron protein of nitrogenase. Detailed investigation of the distribution and abundance of nitrogen fixing prokaryotes in marine ecosystems has been restrained by a lack of suitable methods. Therefore, as part of a larger project to develop and employ an in situ molecular detection method for diazotrophic bacterioplankton, we have sequenced a large segment (ca. 650 bp) of nifH from members of the genus Vibrio. This fragment represents approximately 75% of the complete coding sequence of nifH. Sequence was obtained from a single PCR product, amplified using two 26-mer degenerate primers which we designed. Initial analysis of nifH from Vibrio natriegenes indicates this sequence is most similar to nifH from Klebsiella pneumonae and is grouped with nifH sequences from other gamma proteobacteria. Analysis of this large fragment of nifH will be of assistance in determining those regions of nifH which could be used to develop PCR based detection methods for specific groups of diazotrophs.
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
Code: CS55TH0857S