International Journal of Biology Research

Authors
Babangida Isa, Junaidu Sanusi, Haruna Yahaya Ismail, Bashir Aliyu

Abstract
Plant growth is a major index in sustainable crop production and food security. Plant growth is controlled by a number of factors that often create stress conditions. Among the prominent biotic factors are microorganisms including plant growth-promoting rhizobacteria. In the present study, the rhizosphere of cowpea was explored with a view to detecting and identifying plant growth-promoting bacteria. Soil samples were collected from the cowpea root zone and subjected to microbial analysis using standard procedures. The isolates were screened for their ability to produce and exhibit plant growth properties. A total of 17 bacterial species were isolated and identified as Paenibacillus spp. (11.76%), Pseudomonas spp. (11.76%), Corynebacterium spp. (11.76%), Micrococcus spp. (11.76%), Paraburkholderia sprentiae CRA1 (5.88%), Burkholderia gladioli CRA4 (5.88%), Arthrobacter sp. URR2 (5.88%) with the predominance of Bacillus spp. (35.29%). Some species including Pseudomonas aeruginosa CRD2, Micrococcus varians CRA3 and Corynebacterium kutsceri CRB5 were able to show multiple traits including cellulase and pectinase production; ammonium and indole acetic acid (IAA) production and phosphate solubilization. Paraburkholderia sprentiae CRA1 showed the highest (144.4%) phosphate solubilization efficiency followed by Paenibacillus validus CRD1 (137.5%) and Paenibacillus alvei CRB4 (133.3%). As majority of the isolates were cellulase, pectinase, and ammonium producers, more than 50% of the isolates were phosphate solubilizers. The ability of the bacteria to express one or more of these traits is an indication of their ability to enhance plant growth and performance. The need to explore their individual and additive effect with a view to harnessing their potential is therefore recommended.