Isolation and characterization of plant growth-promoting strain pantoea NII-186. from western ghat forest soil, India

Abstract

Aims: To isolate plant growth-promoting bacterium from Western Ghat forests in India. Methods and Results: 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 mu g of Ca(3)PO(4) ml(-1) day(-1)), and produce IAA (59 mu g) 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.

Conclusions: 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.

Significance and Impact of the Study: 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.