Abstract

Production of the crop is affected by deficiency of fertilizers and low number of plant growth promoting rhizobacteria in soil. At the present study, Pseudomonas fluorescens isolates possess a variety of promising properties which make it a good plant growth promoting traits. A total of twenty-five Pseudomonas fluorescens isolates were obtained and characterized on the basis of their colony morphology, microscopy and biochemical test. Isolates growing P. fluorescens isolates on the King’s B medium at 25ºc to 30ºc for 48 hours. The plates were exposed to UV light for 30 seconds and the isolate with pigment were exhibiting the fluorescence. All the isolates showed creamy translucent, mucoid, and circular shape colony morphology. Colonies having Pseudomonas like morphology were microscopically analyzed and those depicting rod shaped, gram negative bacteria were selected. All Pseudomonas isolates were further characterized by different biochemical test. It showed positive results in all the biochemical tests (Citrate utilization test, Methyl red test, Catalase test, Oxidase test, Nitrate reduction test, Urease test). Further, antibiotic sensitivity profiling of these isolates was done all the isolates were found resistant to Amoxyclav and Erythromycin and all were inhibited by the Ciprofloxacin by forming a clear zone of 15mm. These Pseudomonas isolates were tested for physiological efficiency on different pH (6, 7, and 8). All isolates grew well on alkaline medium of pH value 8. P. fluorescens for plant growth promoting activities in green house showed a positive result. These isolates can be used as potential biofertilizers and plant growth promoter.