Isolation and molecular characterization of microorganisms with biofertilizer potential

Abstract

Biofertilizers are microbial-agro products containing mixed culture of microorganisms that promote plant growth, yield, soil quality and disease control. This study aimed to isolate, identify and screen microorganisms with biofertilizer potentials for application in farms. Soil samples were collected from farmland and waste-dump soils around University of Port Harcourt. The various microorganisms were isolated and estimated using nutrient agar, potato dextrose agar, cetrimide agar and Ashby’s agar. The microorganisms were screened for biofertilizer potentials based on nitrogen fixation, potassium and phosphate solubilization using Pikovskaya media. The results obtained from this study showed that thefarmland soil sample had a total heterotrophic bacterial and fungal counts of 5.045±0.02 and 4.220±0.02 Log₁₀Cfu/gwhile the corresponding values in the waste-dump soil was 4.890±0.30 and 3.505±0.30 Log₁₀Cfu/g respectively. After screening, the microorganisms with biofertilizer potentials were identified as Aspergillus niger, Penicillium chrysogenum, Bacillus cereus, Bacillus licheniformis, Pseudomonas fluorescens and Azotobacter chroococcum. Findings from this study have demonstrated that the microorganisms isolated from the farmland soil were more adept at nitrogen fixation and solubilizing insoluble potassium and phosphate compounds than their counterparts in waste-dump soil. These microorganisms have shown potentials to improve soil fertility and crop productivity in a sustainable way.