Please use this identifier to cite or link to this item: http://hdl.handle.net/10603/2561
Title: Study of ability and role of native bacteria on the Bioleaching of Zinc and optimization of growth conditions
Researcher: Mansoor, Fahimeh Nemati
Guide(s): Shitole, M G
Keywords: Biotechnology
Bioleaching of Zinc
Upload Date: 1-Sep-2011
University: University of Pune
Completed Date: 2009
Abstract: The term bioleaching refers to the conversion of an insoluble metal (usually a metal sulfide, e.g., CuS, NiS, and ZnS) into a soluble form (usually the metal sulfate, e.g., CuSO4, NiSO4, ZnSO4). When this happens, the metal is extracted into water; this process is called bioleaching. These processes are oxidative in nature and when microorganisms mediate these, they are termed as biooxidation. Here the recovery of a metal is enhanced by microbial decomposition of the mineral. In this process the metal being recovered remains in insoluble form. An example is the recovery of gold from arsenopyrite ores where the gold remains in the mineral after biooxidation and is extracted by cyanide in a subsequent steps. Hence the term bioleaching is clearly inappropriate when referring to gold recovery (although arsenic, iron, and sulfur are bioleached from the mineral). Biomining is a general term that may be used to refer to both the processes. Populations of leaching bacteria are found ubiquitously and may be isolated with little difficulty wherever oxidizable ore bodies are exposed to the surface. However, newly isolated bacterial populations cannot be expected to oxidize ores at very high rates. The challenge to the biotechnologist is to improve the rate of cell growth and ore oxidation by the microbes responsible for leaching. Different types of bacteria have been isolated from industrial leaching operations or from natural leaching sites or mines etc. These strains are capable of attacking sulfides. These are classified according to their preferred temperatures for growth Mesophilic bacteria such as Aciditiobacilus ferroxidans , Aciditiobacilus thiooxidans and Leptosprillium ferooxidans operating at ~ 40° C are the most extensively used microorganisms for the bioleaching of sulphide minerals with commercial interest. All three of these species are highly acidophilic (optimal pH 1.5 2), obligate autotrophs, and grow optimally at temperatures ranging from 25 to 35°C.
Pagination: 213p.
URI: http://hdl.handle.net/10603/2561
Appears in Departments:Department of Biotechnology

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02_certificate.pdf11.64 kBAdobe PDFView/Open
03_declaration.pdf12.86 kBAdobe PDFView/Open
04_acknowledgement.pdf54.1 kBAdobe PDFView/Open
05_dedication.pdf13.69 kBAdobe PDFView/Open
06_abstract.pdf61.14 kBAdobe PDFView/Open
07_contents.pdf31.26 kBAdobe PDFView/Open
08_abbreviations.pdf19.83 kBAdobe PDFView/Open
09_chapter 1.pdf529.89 kBAdobe PDFView/Open
10_chapter 2.pdf233.8 kBAdobe PDFView/Open
11_chapter 3.pdf913.52 kBAdobe PDFView/Open
12_chapter 4.pdf236.69 kBAdobe PDFView/Open
13_chapter 5.pdf49.99 kBAdobe PDFView/Open
14_references.pdf205.93 kBAdobe PDFView/Open


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