title: Identification of diazotrophs in the culturable bacterial community associated with roots of Lasiurus sindicus, a perennial grass of Thar Desert, India.
abstract: Lasiurus sindicus is a highly nutritive, drought-tolerant, perennial grass that is endemic to the Thar Desert of Rajasthan, India. Analysis of 16S rRNA coding genes of the bacterial isolates enriched in nitrogen-free semisolid medium, from the surface-sterilized roots of L. sindicus, showed predominance of Gram-negative over Gram-positive bacteria. According to comparative sequence analysis of 16S rDNA sequence data, Gram-positive bacteria with low GC content (Staphylococcus warneri and Bacillus sp.) and high GC content (Micrococcus luteus, Microbacterium sp.) were identified. Gram-negative bacteria included Azospirillum sp., Rhizobium sp., Agrobacterium tumefaciens, and Inquilinus limosus (alpha-proteobacteria); Ralstonia sp., Variovorax paradoxus, and Bordetella petrii (beta-proteobacteria); and Pseudomonas pseudoalcaligenes, Stenotrophomonas sp. (gamma-proteobacteria). The occurrence of nifH sequences in Azospirillum sp., Rhizobium sp., and P. pseudoalcaligenes showed the possibility of supplying biologically fixed nitrogen by the root-associated diazotrophs to the host plant.
authors.affiliation: School of Biotechnology, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Soumitra Paul
authors.initials: SP
authors.lastname: Chowdhury
authors.forename: Michael
authors.initials: M
authors.lastname: Schmid
authors.forename: Anton
authors.initials: A
authors.lastname: Hartmann
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Tripathi
mesh_terms: D000114:Acetylene / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000145:classification; D003889:Desert Climate; D007194:India; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000737:chemistry / Q000145:classification; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D006109:Poaceae / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase; D000114:Acetylene