Isolation, characterization and identification of plant growth-promoting rhizobacteria (PGPR) from the rhizosphere soil of turmeric plant

Plant growth-promoting rhizobacteria (PGPR) are beneficial soil microorganisms that promote plant growth in a several ways that includes phosphate solubilization, nitrogen fixation, and phytohormone synthesis and control of plant diseases. The medicinally valuable crop turmeric (Curcuma longa) also provides an ideal rhizospheric site on which to investigate microorganisms. The knowledge of the associated PGPR can be used to help have a sustainable agriculture practice and have better crop productivity. This study explored the effects of rhizospheric soil-derived plant growth-promoting rhizobacteria (PGPR). Six of the fifty bacterial strains that were identified were chosen. for further analysis, these isolates were characterized based on functional traits, including phosphorus, zinc, siderophore synthesis, indole-3-acetic acid synthesis, and potassium solubilization, and salt tolerance. Isolates A and B showed significantly higher siderophore synthesis, phosphate solubilization, and IAA synthesis. Three isolates synthesized exopolysaccharides, two solubilized zinc, and three solubilized potassium. According to molecular identification using 16S rDNA sequencing, these strains are Bacillus spp.