Isolation and Biochemical Characterization of Indole-3-Acetic Acid (IAA) Produced in Pseudomonas Sp. Isolated from Rhizospheric Soil

Abstract

A phytohormone is a molecule that controls the development of plants. Auxin and cytokines, which may be acquired as synthetic compounds or produced by microorganisms, which promote plant growth, are employed to enhance crop yield. Indole-3-Acetic Acid (IAA) is a key phytohormone that controls a number of physiological processes in plants. Indole-3-acetic acid (IAA), the most prevalent endogenous auxin, is involved in stem elongation and root formation. Auxin levels are usually higher in the rhizosphere. The possibility of rhizosphere bacteria to encourage direct plant development has been recognised as a crucial component of auxin (IAA) production. They promote the growth of lateral roots, which increases the surface area available for nutrition absorption and enhances nutrient and water absorption from the soil. The objective of this research is to isolate, characterise, and identify bacteria that produce indole acetic acid in rhizospheric soil. Bacterial colonies were isolated using the serial dillution technique on nutrient agar medium from rhizospheric soil samples of a rice crop. Five rhizospheric bacterial isolates (RIPB-1 to RIPB-30) were identified as effective Indole acetic acid makers after qualitative screening. The quantity of Indole acetic acid produced by five bacterial strains was tested for up to 120 hours. The amount of Indole acetic acid they could generate ranged from 1 to 11.2 g/ml. The bacterial strain RIPB-20 (11.2 g/ml) generated the highest Indole acetic acid after 72 hours of incubation, followed by RIPB-14. Based on morphological, physiological, and biochemical features, the bacterial isolate RIPB-20 was tentatively identified as Bacillus sp. Finally, the finding shows that the bacteria, which have capacity to produce Indole acetic acid, are good biofertilizer inoculants for growth of plant.