Bambara Groundnut Rhizobacteria Antimicrobial and Biofertilization Potential

Abstract

Bambara groundnut, an underutilized crop has been proved to be an indigenous crop in Africa with the potential for food security. The rhizosphere of Bambara groundnut like other legumes contains several important bacteria that have not been explored for their plant growth-promoting properties. The aim of this research was to determine the potentials of rhizobacteria from Bambara groundnut soil samples as either biofertilizer or biocontrol agents or both to help provide sustainable agriculture in Africa and globally. Analyses of Bambara groundnut rhizospheric soil samples included chemical analysis such as nitrogen content analysis using extractable inorganic nitrogen method as well as cation exchangeable capacity using ammonium acetate method. Plant growth-promoting properties of isolated rhizobacteria tested include indole acetic acid, hydrogen cyanide, phosphate solubilization, 1-aminocyclopropane-1-carboxylate and ammonia production activities using standard methods. In addition, antifungal assay dual culture method was used to analyze the biocontrol properties of the isolates. Phylogenetic analysis using 16S rRNA was also carried out on the isolates. Isolated rhizobacteria from bambara groundnut rhizosphere were cultured. All the isolates were able to produce ammonia and 1-aminocyclopropane-1-carboxylate while 4.65%, 12.28% and 27.91% produced Hydrogen cyanide, Indole acetic acid and solubilized phosphate respectively, making them important targets as biocontrol and biofertilizer agents. The growth of Fusarium graminearum was suppressed in vitro by 6.98% of the isolates. Plant growth promoting activities of rhizobacteria from bambara groundnut rhizosphere reveals that it has great potentials in food security as biofertilizer and biocontrol agent against fungal and bacterial pathogens.