Bacterial Isolation from Groundnut Farm Soil in Katagum, Bauchi State, Nigeria

Background and Objective: Soil is a dynamic ecosystem containing diverse microbial communities that significantly impact crop health and productivity. In groundnut (Peanut) farming, both beneficial and pathogenic soil bacteria influence yield. This study aimed to isolate and identify bacterial species in groundnut farm soil from Katagum, Bauchi State, Nigeria, and to assess its physical and chemical properties to determine their agricultural implications. Materials and Methods: Soil samples were collected from a groundnut farm and analyzed using standard microbiological and physicochemical procedures. Bacteria were isolated through spread plating on nutrient agar and incubated at 37°C for 24 hrs. Biochemical tests, including methyl red, oxidase, catalase, Voges-Proskauer, Indole, Gram staining, and Cot analysis, were employed for bacterial identification. Mineral and heavy metal contents were quantified using atomic absorption spectrophotometry (AAS) following microwave digestion with nitric acid and hydrogen peroxide. Soil texture was evaluated through the sedimentation method using Calgon solution. Results: Two dominant bacterial species, Staphylococcus aureus and Escherichia coli, were isolated and identified. The soil samples showed notable textural differences: One sample contained higher silt (76%) and sand (60%), while the other had increased clay content (46.8%). All procedures were conducted using analytical-grade reagents and calibrated equipment. Conclusion: The study reveals a strong link between soil texture and microbial composition, providing foundational knowledge for improving soil health and enhancing groundnut productivity. The results serve as a basis for future research on microbial interventions and inform soil management strategies for sustainable agriculture in the region.