Isolation and Characterization of Nitrogen-Fixing Bacteria and Producing IAA (Indole Acetic Acid) From Rice Rhizosphere from The Soppeng Regency

Rhizosphere microorganisms in the plant root area can increase the ability of plants to utilize nutrients, tether free nitrogen in the air, and can produce Indole Acetic Acid compounds. This study aims to obtain rice rhizosphere bacteria as nitrogen-fixing and producing Indole Acetic Acid which has the potential as a booster for plant growth. Rhizosphere bacteria are isolated from the soil around the roots of rice plants through serial dilution. There were thirty isolates of rhizosphere bacteria that could grow on agar nutrient medium. Morphological and biochemical characterization results obtained seventeen isolates that had different morphological, gram reaction, and catalase enzyme content. Ten isolates of rhizosphere bacteria that can grow on Burk's nitrogen medium and produce growth hormone Indole Acetic Acid. The highest concentration of Indole Acetic Acid was found in bacteria with HR2P isolate code, followed by HR15P isolate and HR29P isolate. The rhizosphere bacterial isolate is an isolate that has the potential as a bacterium for plant growth.