Some Characteristics of a Plant Growth Promoting Enterobacter sp. Isolated from the Roots of Maize

Some properties of an Enterobacter sp. isolated from the roots of maize are described. Isolation was carried out using the semisolid enrichment culture technique and subsequent plating, both on nitrogen free biotin medium. Morphological, biochemical and phylogenetic characterization using the MicroSeq 16S rDNA technique were employed in identification of isolate, which was revealed to be closest matched at 99.4% with Enterobacter asburiae. The isolate possessed properties of plant growth promoting bacteria. Thus, it produced indole-3-acetic, plant polymer hydrolyzing enzymes, pectinase and cellulase as well as ammonia in vitro. The isolate grew well in the presence of both 3% NaCl and 10 μg of streptomycin. In plate bioassays, isolate promoted the germination of both maize and rice seeds as well as root and lateral root growth resulting in weight increases of seedlings over their controls. Experiments to quantify ability of isolate to promote plant growth was performed using hydroponics solutions and as appropriate, an inoculum of the isolate. Pot experiments were also employed. Results from these studies showed that isolate enhanced nitrogen accumulation and significantly (P < 0.05), improved the growth of maze seedlings over controls. Isolate has potential for utilizetion as inocula for sustainable production of cereals.