Isolation, Characterization and Identification of Azorhizophilus Paspali SHF1

The symbiotic relationship between nitrogen-fixing bacteria and plants plays a crucial role in improving soil fertility and promoting sustainable agricultural practices. This study focuses on the isolation, characterization, and molecular identification of a nitrogen-fixing bacterial strain, Azorhizophilus paspali SHF1, obtained from the rhizosphere of different plant species. Soil samples were collected from agricultural fields of Latur region known for high productivity, and bacterial isolation was performed using nitrogen-free selective media, specifically Jensen’s medium, to enrich nitrogen-fixing bacterial colonies. The isolated strain SHF1 underwent a series of morphological and biochemical characterizations. Gram staining revealed the strain to be a Gram-negative, rod-shaped bacterium, with colony morphology being mucoid and circular. Biochemical assays, including catalase, oxidase, nitrate reduction, and indole production tests, were conducted to further characterize the isolate. The strain exhibited nitrogen-fixing capabilities, as indicated by positive nitrogenase activity using the acetylene reduction assay (ARA). For molecular identification, 16S rRNA gene sequencing was employed. The sequence obtained was compared against the GenBank database using BLAST, which confirmed a close similarity to Azorhizophilus paspali, with 99% sequence identity. Phylogenetic analysis also confirmed the taxonomic position of SHF1 within the Azorhizophilus genus. The strain demonstrated significant nitrogenase activity, indicating its potential application in biofertilizer production. Additionally, plant growth-promoting attributes such as the production of indole acetic acid (IAA) and phosphate solubilization were observed, highlighting the strain’s ability to enhance plant growth. The findings of this study suggest that Azorhizophilus paspali SHF1 could serve as an effective biofertilizer, contributing to nitrogen cycling in agricultural ecosystems and reducing reliance on synthetic fertilizers. Its potential to improve plant growth and productivity offers promising avenues for sustainable agriculture, particularly in low-input farming systems.