Isolation and Characterization of Indole Acetic Acid, Gibberellic Acid, and Phosphate Solubilizing Microorganisms from the Rhizospheric Soil of Ocimum sanctum.

Abstract

This research paper investigates the rhizospheric soil of Ocimum sanctum, commonly known as holy basil, to isolate and characterize microorganisms capable of producing indole acetic acid (IAA), gibberellic acid (GA), and phosphate solubilization. The rhizosphere, the region of soil surrounding plant roots, harbors a diverse community of microorganisms that play crucial roles in plant growth and development. Among these microorganisms, those capable of producing phytohormones like IAA and GA, as well as phosphate solubilizers, hold significant potential for enhancing plant growth and nutrient uptake.

The study employed various isolation and characterization techniques to identify and assess the functional attributes of the isolated microorganisms. Initial isolation was conducted using selective media supplemented with specific substrates to enrich for IAA, GA, and phosphate solubilizing microorganisms.

Subsequent characterization included morphological, biochemical, and molecular analyses to identify the isolates at the species level and evaluate their plant growth-promoting abilities.The results revealed a diverse array of microorganisms inhabiting the rhizospheric soil of Ocimum sanctum, with a notable proportion exhibiting the ability to produce IAA, GA, or solubilize phosphate.

 Morphological characterization indicated the presence of both bacteria and fungi, suggesting a complex microbial community associated with the rhizosphere. Biochemical tests provided insights into the metabolic capabilities of the isolates, while molecular techniques such as PCR and sequencing facilitated their taxonomic identification. Functional assays demonstrated the plant growth-promoting potential of the isolated microorganisms. IAA and GA-producing strains exhibited significant stimulatory effects on root elongation and shoot growth in bioassays, indicating their potential role in enhancing plant growth and development. Similarly, phosphate solubilizing isolates demonstrated the ability to release phosphate from insoluble sources, which could contribute to improved nutrient availability for plants.