Joshi, P M and Juwarkar, A (2009) In Vivo Studies to Elucidate the Role of Extracellular Polymeric Substances from Azotobacter in Immobilization of Heavy Metals. Environmental Science & Technology, 43. pp. 5884-5889.

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The role of extracellular polymeric substances (EPS) produced by the heavy metal-resistant strain of Azotobacter spp. in restricting the uptake of cadmium (Cd) and chromium (Cr) by wheat plants cultivated in soils contaminated with the respective heavy metals has been demonstrated. A heavy metalresistant strain of Azotobacter spp. was isolated and identified. Minimum inhibitory concentrations (MIC) of Cd2+ and CrO4 2- were determined to be 20 and 10 mg L-1, respectively. Under in vitro conditions, the EPS produced by the strain could bind 15.17 ( 0.58 mg g-1 of Cd2+ and 21.9 ( 0.08 mg g-1 of CrO4 2-. Fourier transform infrared spectra of the EPS revealed the presence of functional groups like carboxyl (-COOH)andhydroxyl (-OH), primarily involved in metal ion binding. Under pot culture experiments, the isolated strain of Azotobacter was added to the metal-contaminated soils in the form of free cells and immobilized cells. The total Azotobacter count and plant metal concentrations under different treatments showed a negative coefficient between the Azotobacter population and plant Cd (-0.496) and Cr (-0.455). Thus it could be inferred that Azotobacter spp. is involved in metal ion complexation either throughEPSor through cell wall lipopolysaccharides (LPS)

Item Type: Article
Subjects: Environmental Biotechnology
Depositing User: Users 6 not found.
Date Deposited: 14 Mar 2012 05:51
Last Modified: 14 Mar 2012 05:51

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