Surface chemical studies of Thiobacillus ferrooxidans with reference to copper tolerance

Das, Amitabha and Modak, Jayant M and Natarajan, KA (1998) Surface chemical studies of Thiobacillus ferrooxidans with reference to copper tolerance. In: Antonie van Leeuwenhoek, 73 (03). pp. 215-222.

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Abstract

A strain of Thiobacillus ferrooxidans was adapted to grow at higher concentrations of copper by single step culturing in the presence of 20 g/L (0.314 mol/L) cupric ions added to 9K medium. Exposure to copper results in change in the surface chemistry of the microorganism. The isoelectric point of the adapted strain (pI=4.7) was observed to be at a higher pH than that of the wild unadapted strain(pI=2.0). Compared to the wild strain, the copper adapted strain was found to be more hydrophobic and showed enhanced attachment efficiency to the pyrite mineral. The copper adsorption ability of the adapted strain was also found to be higher than that of the wild strain. Fourier transform infrared spectroscopy of adapted cells suggested that a proteinaceous new cell surface component is synthesized by the adapted strain. Treatment of adapted cells with proteinase-K, resulted in complete loss of tolerance to copper, reduction in copper adsorption and hydrophobicity of the adapted cells. These observations strongly suggest a role played by cell surface modifications of Thiobacillus ferrooxidans in imparting the copper tolerance to the cells and bioleaching of sulphide minerals.

Item Type:	Journal Article
Publication:	Antonie van Leeuwenhoek
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Keywords:	Thiobacillus ferrooxidans;copper tolerance;cell surface modifications.
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	11 Dec 2009 09:48
Last Modified:	19 Sep 2010 05:27
URI:	http://eprints.iisc.ac.in/id/eprint/19333

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