Amplified Ribosomal DNA Restriction Analysis for the Preliminary Characterization of Native Diazotrophs Azotobacter, Acetobacter and Azospirillum

摘要

A 16S rRNA gene-based fingerprinting method was developed for the preliminary characterization of native diazotrophs bacterial isolates Azotobacter, Acetobacter and Azospirillum tested with reference strains belonging to the free-living nitrogen-fixing bacterial group. According to this method, the 16S rRNA gene was amplified using universal primers and PCR products were subsequently digested with TaqI, BamHI, Hinfl and Haelll. The analysis of the restriction profiles obtained showed that the methodis able to define a unique species-specific phylotype (SSP) for each of the native diazotrophic bacterial isolates. Phylogenetic analysis of I OS rRNA indicated that these diazotrophic bacterial isolates belonged to respective genus Azotobacter, Acetobacter and Azospirillum and closely related to standard strains.