Isolation and characterization of plant growth-promoting strain Pantoea NII-186. From Western Ghat forest soil, India

To isolate plant growth-promoting bacterium from Western Ghat forests in India. A Gram-negative, rod shaped, cream white coloured strain Pantoea NII-186 isolated from Western Ghat soil sample. The taxonomic position of the bacterium was confirmed by sequencing of 16S rRNA and phylogenetic analysis. A strain grew at a wide range of temperature ranging from 5-40 degrees C, but optimum growth was observed at 28-30 degrees C.

It showed multiple plant growth-promoting attributes such as phosphate solubilization activity, indole acetic acid (IAA) production, siderophore production and HCN production. It was able to solubilize (28 microg of Ca(3)PO(4) ml(-1) day(-1)), and produce IAA (59 microg) at 28 degrees C. The solubilization of insoluble phosphate was associates with a drop in the pH of the culture medium.

Pantoea sp. NII-186 tolerate to different environmental stresses like 5-40 degrees C, 0-7% salt concentration and 4-12 pH range. The 16S rRNA gene sequence confirmed that the isolate NII-186 was belongs to Pantoea genus and showed considerable differences in physiological properties with previously reported species of this genus.

Isolate NII-186 possessed multiple attributes of plant growth-promoting activity. Hence in the context it is proposed that Pantoea sp. NII-186, could be deployed as an inoculant to attain the desired plant growth-promoting activity in agricultural environment.