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Microbially induced selective flotation of sphalerite from galena using mineral-adapted strains of Bacillus megaterium

Vasanthakumar, B and Ravishankar, H and Subramanian, S (2013) Microbially induced selective flotation of sphalerite from galena using mineral-adapted strains of Bacillus megaterium. In: COLLOIDS AND SURFACES B-BIOINTERFACES, 112 . pp. 279-286.

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Official URL: http://dx.doi.org/10.1016/j.colsurfb.2013.07.034

Abstract

The selective flotation of sphalerite from a sphalerite-galena mineral mixture has been achieved using cells and extracellular secretions of Bacillus megaterium after adaptation to the chosen minerals. The extracellular secretions obtained after thermolysis of bacterial cells adapted to sphalerite yield the highest flotation recovery of sphalerite with a selectivity index value of 24.5, in comparison to the other cellular and extra-cellular bio-reagents studied. The protein profile for the unadapted and mineral-adapted cells has been found to differ distinctly, attesting to variation in the yield and nature of extra-cellular polymeric substances (EPS). The changes induced in the bacterial cell wall components after adaptation to sphalerite or galena with respect to the contents of phosphate, uronic acid and acetylated sugars of B. megaterium have been quantified. The role of the dissolved metal ions from the minerals as well as that of the constituents of extracellular secretions in modulating the surface charge of the bacterial cells as well as the minerals under study has been confirmed using various enzymatic treatments of the bacterial cells. It has been demonstrated that the induction of additional molecular weight protein fractions as well as the higher amount of extracellular proteins and phosphate secreted after adaptation to sphalerite vis-A-vis galena are contributory factors for the selective separation of sphalerite from galena. (C) 2013 Elsevier B.V. All rights reserved.

Item Type: Journal Article
Additional Information: Copyright for this article belongs to the ELSEVIER SCIENCE BV, NETHERLANDS
Keywords: Bacillus megaterium; Mineral adaptation; Sphalerite; Galena; Bioflotation
Department/Centre: Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Depositing User: Id for Latest eprints
Date Deposited: 03 Feb 2014 11:31
Last Modified: 03 Feb 2014 11:31
URI: http://eprints.iisc.ac.in/id/eprint/48303

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