A. Banerjee, P. Acharyya and S. Tripathi
Abstract
Cadmium resistant bacteria were isolated from contaminated soil and were examined for production of extracellular polymeric substances to understand the characteristic feature of the selected bacterium under cadmium toxicity. The morphological identifications followed by carbohydrate utilization and 16S rDNA analysis along with phylogenetic connection of the selected bacterium linked it to Mammaliicoccus sciuri. The Scanning electron microscopic images showed the presence of extracellular polymeric substances under the influence of cadmium and the Fourier Transform Infrared Spectroscopy spectral images confirmed the presence of extracellular polymeric substances. The spectral images show different peaks of the stretching vibrations for related ligand bindings and presence of polysaccharides, amides and lipids. The Energy Dispersive X-ray report confirms the absorption of cadmium within the bacterial extracellular polymeric substances. An experiment was conducted in grow bags separately containing sterile soil and Amaranthus seeds along with 10 pmm, 50 ppm and 100 ppm of Cadmium solution. Similar setups were prepared along with the selected bacterial strain to study the influence of the bacterium on Amaranthus under cadmium toxicity. The result shows a successful development of cadmium tolerance in Amaranthus on application of cadmium tolerant extracellular polymeric substances producing bacterium that lowered the absorption of the metal at different parts of the plant.