BIO STIMULATION OF INDIGENOUS SOIL BACTERIA USING STIMULATING MEDIUM (KH₂PO₄)

Abstract

This study investigated the isolation, identification, and bio stimulation of indigenous soil bacteria obtained from soil samples collected behind the Vice Chancellor’s quarters at Usmanu Danfodiyo University, Sokoto (UDUS). The research aimed to isolate and characterize bacterial species and evaluate their growth response using a stimulating medium composed of nutrient agar supplemented with urea and phosphate buffer (KH₂ PO₄). Soil samples were serially diluted and cultured on nutrient agar, and distinct bacterial colonies were purified for morphological and biochemical characterization. The isolates were identified based on Gram staining and biochemical tests, including catalase, citrate, indole, oxidase, urease, and sugar fermentation reactions. Four bacterial species were identified: Enterococcus casseliflavus (VC A), Citrobacter freundii (VC B), and Micrococcus luteus (VC C). Among them, E. casseliflavus and C. freundii exhibited strong urease activity, indicating their potential role in urea hydrolysis and nitrogen transformation. All isolates showed significant growth on urea–phosphate-enriched media, demonstrating that the stimulating medium effectively enhanced bacterial proliferation compared to the control. These findings confirm that indigenous soil bacteria in the UDUS environment possess metabolic versatility and adaptability to nutrient-enriched conditions. This study concludes that urea and phosphate supplementation can significantly promote the growth and metabolic activities of indigenous soil bacteria. Such bacteria, particularly E. casseliflavus and C. freundii, can be harnessed as potential biofertilizers or biostimulants to enhance soil fertility and support sustainable agricultural practices in semi-arid regions like Sokoto.