Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state

Brazilian Journal of Microbiology

Érica. L. Reinhardt²  Patrícia L. Ramos¹  Gilson P. Manfio¹  Heloiza R. Barbosa¹  Crodowaldo Pavan¹  Carlos A. Moreira-filho¹ 

[1] ,FundacentroSão Paulo SP ,Brasil

关键词: endophytic bacteria;    diazotrophs;    selective isolation;    molecular systematics;    bactéria endofítica;    diazotróficas;    isolamento seletivo;    sistemática molecular;   

DOI  :  10.1590/S1517-83822008000300002

来源: SciELO

【 摘 要 】

Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data.

【 授权许可】

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