Stable isotope probing with 15N2 reveals novel noncultivated diazotrophs in soil.

ABSTRACT: Biological nitrogen fixation is a fundamental component of the nitrogen cycle and is the dominant natural process through which fixed nitrogen is made available to the biosphere. While the process of nitrogen fixation has been studied extensively with a limited set of cultivated isolates, examinations of nifH gene diversity in natural systems reveal the existence of a wide range of noncultivated diazotrophs. These noncultivated diazotrophs remain uncharacterized, as do their contributions to nitrogen fixation in natural systems. We have employed a novel 15N2-DNA stable isotope probing (5N2-DNA-SIP) method to identify free-living diazotrophs in soil that are responsible for nitrogen fixation in situ. Analyses of 16S rRNA genes from 15N-labeled DNA provide evidence for nitrogen fixation by t

SUBMITTER: Buckley DH 

PROVIDER: S-EPMC1907113 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature