Development of a direct isolation procedure for free-living diazotrophs under controlled hypoxic conditions.

ABSTRACT: Free-living diazotrophs are diverse and ubiquitous in soil, contributing the nitrogen pool in natural ecosystems. The isolation of nitrogen-fixing microorganisms has relied on semisolid nitrogen-free medium enrichment, followed by multiple subculturing steps. These procedures limit the diversity of recovered isolates. In the current study, we investigated three different isolation strategies for free-living diazotrophs using a soil sample from the Amazon forest. The methods were (i) direct plating on solid nitrogen-free medium under a 2% O(2) concentration, (ii) enrichment in semisolid nitrogen-free medium before plating on solid nitrogen-free medium under 2% O(2), and (iii) enrichment followed by subculturing in the semisolid nitrogen-free medium before plating on nitrogen containing medi

SUBMITTER: Mirza BS 

PROVIDER: S-EPMC3406155 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature