Isolation and characterization of pgpb organisms from the rhizosphere of maize (zea mays. l)

PGPB (Plant growth promoting bacteria) are the group of bacteria which can able to enhance or influence the growth, development and yield of crop plants. The beneficial effect on the growth of crop plants actually due to ‘N’ fixation, Phosphorus solubilization and growth promoting substances production (IAA, GA3, etc.). PGPB includes the vital ‘N’ fixing diazotrophs namely Azospirillum and a known endophytic diazotroph Gluconacetobacter and also phosphorus solubilizer namely Bacillus and Pseudomonas. In the present research about ten isolates of Azospirillum, Bacillus and Pseudomonas were isolated from ten different rhizosphere soil samples of maize from Salem District. These isolates were purified, characterized and identified as Azospirillum brasilense, Bacillus megaterium and Pseudomonas fluorescens. In addition the isolation of Gluconacetobacter diazotrophicus from the rhizosphere soil samples of maize ends in failure whereas the same organisms was successfully isolated from root extract of maize and purified and all these isolates were maintained for further study.