Differential distribution and abundance of diazotrophic bacterial communities across different soil niches using a gene‐targeted clone library approach. Issue 2 (1st October 2014)

• Record Type: Journal Article
• Authors: Yousuf, Basit; Kumar, Raghawendra; Mishra, Avinash; Jha, Bhavanath
• Is Part Of: FEMS microbiology letters. Volume 360:Issue 2(2014:Nov.)
• Page Start: 117
• Page End: 125
• Publication Date: 2014-10-01
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1111/1574-6968.12593
• Languages: English
• ISSNs: 0378-1097

Abstract

<abstract abstract-type="main" id="fml12593-abs-0001"> <title>Abstract</title> <p>Diazotrophs are key players of the globally important biogeochemical nitrogen cycle, having a significant role in maintaining ecosystem sustainability. Saline soils are pristine and unexplored habitats representing intriguing ecosystems expected to harbour potential diazotrophs capable of adapting in extreme conditions, and these implicated organisms are largely obscure. Differential occurrence of diazotrophs was studied by the <italic>nifH</italic> gene‐targeted clone library approach. Four <italic>nifH</italic> gene clone libraries were constructed from different soil niches, that is saline soils (low and high salinity; EC 3.8 and 7.1 ds m<sup>−1</sup>), and agricultural and rhizosphere soil. Additionally, the abundance of diazotrophic community members was assessed using quantitative PCR. Results showed environment‐dependent metabolic versatility and the presence of nitrogen‐fixing bacteria affiliated with a range of taxa, encompassing members of the <italic>Alphaproteobacteria</italic>, <italic> Betaproteobacteria</italic>, <italic> Deltaproteobacteria</italic>, <italic> Gammaproteobacteria</italic>, <italic> Cyanobacteria</italic> and <italic>Firmicutes</italic>. The analyses unveiled the dominance of <italic>Alphaproteobacteria</italic> and <italic>Gammaproteobacteria</italic> (<italic>Pseudomonas</italic>, <italic> Halorhodospira</italic>, <italic> Ectothiorhodospira</italic>, <italic> Bradyrhizobium</italic>, <italic> Agrobacterium</italic>, <italic> Amorphomonas</italic>) as nitrogen fixers in coastal–saline soil ecosystems, and <italic>Alphaproteobacteria</italic> and <italic>Betaproteobacteria</italic> (<italic>Bradyrhizobium</italic>, <italic> Azohydromonas</italic>, <italic> Azospirillum</italic>, <italic> Ideonella</italic>) in agricultural/rhizosphere ecosystems. The results revealed a repertoire of novel nitrogen‐fixing bacterial guilds particularly in saline soil ecosystems.</p> </abstract>