Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils.

ABSTRACT: The genus Bradyrhizobium has served as a model system for studying host-microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbio

SUBMITTER: VanInsberghe D 

PROVIDER: S-EPMC4611507 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature