Asian Journal of Microbiology and Biotechnology

Soybean (Glycine max) is a leguminous crop that relies on symbiotic nitrogen fixation by rhizobacteria for optimal growth and productivity. This study focuses on the isolation and functional characterization of Rhizobium spp. from the Ratlam district of Madhya Pradesh, India. Soybean nodule samples were collected from different soybean-growing regions and rhizobium spp. were isolated by using Yeast Extract Mannitol Agar (YEMA) media. A total of 110 bacteria were isolated from root nodule samples collected from five villages of Ratlam district, Madhya Pradesh, India. Out of 110 isolates, 14 different bacterial isolates were selected for, colony morphology and characterized on the basis of microscopy and biochemically. The isolates could survive at temperatures between 4 and 45 °C (optimum 30 °C), and pH 5–11 (optimum 8). Additionally we have determine the plant growth promoting trails i.e., phosphate solubilizaion, potassium solubilization, production of indole-3-acetic acid (IAA), ammonia, and hydrogen cyanide (HCN). Most of the isolates exhibited plant growth-promoting (PGP) traits. The study concludes that native Rhizobium isolates from the Malwa region possess distinct physiological and plant growth-promoting capabilities. These findings highlight their potential as region-specific bioinoculants to improve soil fertility and support sustainable soybean production under local agroclimatic conditions. This significance of this work to identifies and evaluates native Rhizobium from the Malwa region that can enhance soybean growth, yield, and soil fertility.