Journal of Pure and Applied MicrobiologyVol. 8 No. 6

Assess the Role of Exopolysaccharide (EPS) Producing Bacteria in Soil Moisture Stress Alleviation

Devendra Singh1, Rajendra Prasad Meena2, Sukumar Taria3 and Geeta Singh*

1Division of Microbiology, Indian Agricultural Research Institute 2National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi - 110012, India. 3Division of Plant Physiology, Indian Agricultural Research Institute *Principal Scientist, Division of Microbiology, Indian Agricultural Research Institute, New Delhi - 110012, India.

Received on 06 August 2014 and accepted on 01 October 2014

 

ABSTRACT

A pot experiment was conducted to elucidate the effect of inoculating three exopolysaccharide (EPS) producing bacterial isolates namely Bacillus cereus, Microbacterium resistens and Pseudomonas sp. on the soil physical properties in the rhizosphere of Triticum aestivum L. Inoculation of wheat seeds with above three isolates caused a significant increase in the root-adhering soil (RAS) dry mass (dm) per root tissue (RT) dry mass (RAS/RT). The increase recorded due to Microbacterium resistens inoculation at -0.55 MPa hydric level after 20 DAS in RAS/RT was 157 % over the uninoculated control. Intense colonization of the wheat rhizosphere by these EPS producing bacteria was also associated with significant increase of mean weight diameter (MWD) and water stable aggregate (>250?m). Scanning electron microscopic studies showed the formation of biofilm of inoculated bacteria on the root surface and this, along with a better soil structure, might have protected the plants from the water stress. We demonstrate that EPS-producing bacteria were able to alleviate soils water stress and that EPS-producing bacterial populations play an important role in the rhizosphere through their contribution to soil aggregation.

Keywords : Exopolysaccharide. RAS/RT. Mean Weight Diameter (MWD). Water Stable Aggregate (WSA). Scanning Electron Microscope, Biofilm.