https://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&feed=atom&action=historyCopper Mining Using Acidothiobacillus - Revision history2024-03-29T13:24:56ZRevision history for this page on the wikiMediaWiki 1.39.6https://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=65062&oldid=prevBarichD at 14:30, 23 July 20112011-07-23T14:30:24Z<p></p>
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<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">{{Curated}}</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:BioleachingPlantKCCLUganda.jpg|thumb|400px|right|Figure 1. A copper bioleaching plant in Uganda. (http://promine.gtk.fi/about/WorkPackage4.html)]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:BioleachingPlantKCCLUganda.jpg|thumb|400px|right|Figure 1. A copper bioleaching plant in Uganda. (http://promine.gtk.fi/about/WorkPackage4.html)]]</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Introduction=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Introduction=</div></td></tr>
</table>BarichDhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64879&oldid=prevGipsonAndrew: /* Copper Bioleaching Techniques */2011-05-12T21:06:27Z<p><span dir="auto"><span class="autocomment">Copper Bioleaching Techniques</span></span></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Modern biomining processes are large-scale operations that involve the mining of ores and processing for several months (Fig. 1). Either through strip-mining or blasting, raw ore is obtained.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Modern biomining processes are large-scale operations that involve the mining of ores and processing for several months (Fig. 1). Either through strip-mining or blasting, raw ore is obtained <ins style="font-weight: bold; text-decoration: none;">for extraction of copper</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64878&oldid=prevGipsonAndrew: /* Improvements to the Biomining Process */2011-05-12T21:05:54Z<p><span dir="auto"><span class="autocomment">Improvements to the Biomining Process</span></span></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Improvements to the Biomining Process==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Improvements to the Biomining Process==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure <del style="font-weight: bold; text-decoration: none;">#</del>. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. <del style="font-weight: bold; text-decoration: none;">#</del>). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure <ins style="font-weight: bold; text-decoration: none;">4</ins>. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. <ins style="font-weight: bold; text-decoration: none;">4</ins>). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions and in the presence of certain toxic metals such as arsenic ''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates. Improvement of the nutrient conditions in the heap reactor can increase the ''At. ferrooxidans'' population, which can be achieved through the addition of phosphate (Varela ''et al.'' 1998).</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions and in the presence of certain toxic metals such as arsenic ''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates. Improvement of the nutrient conditions in the heap reactor can increase the ''At. ferrooxidans'' population, which can be achieved through the addition of phosphate (Varela ''et al.'' 1998).</div></td></tr>
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</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64877&oldid=prevGipsonAndrew at 21:05, 12 May 20112011-05-12T21:05:17Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A more inexpensive and immediately practical way than genetic modification to improve biomining is through optimization of industrial techniques. <i>In situ</i> biomining does away with the ore mining process altogether; acidified leach liquor is pumped directly into the ground and the copper is solubilized utilizing preexisting bacteria in the ore deposits. The copper-rich liquor is extracted from wells dug beneath the deposits (Rawlings 2002). By eliminating the physical act of ore mining, a significant portion of the costs is cut from the process.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A more inexpensive and immediately practical way than genetic modification to improve biomining is through optimization of industrial techniques. <i>In situ</i> biomining does away with the ore mining process altogether; acidified leach liquor is pumped directly into the ground and the copper is solubilized utilizing preexisting bacteria in the ore deposits. The copper-rich liquor is extracted from wells dug beneath the deposits (Rawlings 2002). By eliminating the physical act of ore mining, a significant portion of the costs is cut from the process.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">=Conclusion=</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Bioming has proved to be a cheaper, more efficient, and more environmentally-friendly alternative than non-biologically mediated techniques for copper mining, and the chemolithotrophic bacteria ''At. ferrooxidans'' has proven to be an essential part of this process. Much research is still underway to develop improvements, and future applications have included using biologically-engineered bacteria to mine extraterrestrial bodies such as the moon and large meteors (Ragozzine 2004). Whatever directions biomining will take in the future, it will doubtlessly prove to be immensely beneficial in a future with dwindling resources.</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=References=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=References=</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.australianminesatlas.gov.au/education/fact_sheets/copper.jsp Australian Atlas of Minerals, Resources, and Processing Centres.]<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.australianminesatlas.gov.au/education/fact_sheets/copper.jsp Australian Atlas of Minerals, Resources, and Processing Centres.]<br></div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Rawlings DE, Coram NJ, Gardner MN, Deane SM (1999) ''Thiobacillus caldus'' and ''Leptospirillum ferrooxidans'' are widely distributed in continuous flow biooxidation tanks used to treat a variety of metal containing ores and concentrates. In ''Biohydrometallurgy and the Environment Towards the 21st Century. Part A'', ed. Amils R and Ballester A. 777-786. Amsterdam: Elsevier<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Rawlings DE, Coram NJ, Gardner MN, Deane SM (1999) ''Thiobacillus caldus'' and ''Leptospirillum ferrooxidans'' are widely distributed in continuous flow biooxidation tanks used to treat a variety of metal containing ores and concentrates. In ''Biohydrometallurgy and the Environment Towards the 21st Century. Part A'', ed. Amils R and Ballester A. 777-786. Amsterdam: Elsevier<br></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.annualreviews.org/doi/full/10.1146/annurev.micro.56.012302.161052?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed& Rawlings DE (2002) Heavy metal mining using microbes. ''Annu. Rev. Microbiol.'' '''56''': 65-91.]<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.annualreviews.org/doi/full/10.1146/annurev.micro.56.012302.161052?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed& Rawlings DE (2002) Heavy metal mining using microbes. ''Annu. Rev. Microbiol.'' '''56''': 65-91.]<br></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[http://www.niac.usra.edu/files/library/meetings/fellows/mar04/Ragozzine_Darin.pdf Rizzone D (2004) Biomining for ''In-Situ'' Resource Utilization. Accessed May 2011.]<br></ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sand W and Gehrke T (2006) Extracellular polymeric substances mediate bioleaching/biocorrosion via</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sand W and Gehrke T (2006) Extracellular polymeric substances mediate bioleaching/biocorrosion via</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>interfacial processes involving iron(III) ions and acidophilic bacteria. ''Research in Microbiology'' '''157''': 49-56.<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>interfacial processes involving iron(III) ions and acidophilic bacteria. ''Research in Microbiology'' '''157''': 49-56.<br></div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64874&oldid=prevGipsonAndrew: /* Improving the Process */2011-05-12T20:55:12Z<p><span dir="auto"><span class="autocomment">Improving the Process</span></span></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>A more inexpensive and immediately practical way than genetic modification to improve biomining is through optimization of industrial techniques. <i>In situ</i> </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>A more inexpensive and immediately practical way than genetic modification to improve biomining is through optimization of industrial techniques. <i>In situ</i> <ins style="font-weight: bold; text-decoration: none;">biomining does away with the ore mining process altogether; acidified leach liquor is pumped directly into the ground and the copper is solubilized utilizing preexisting bacteria in the ore deposits. The copper-rich liquor is extracted from wells dug beneath the deposits (Rawlings 2002). By eliminating the physical act of ore mining, a significant portion of the costs is cut from the process.</ins></div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=References=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=References=</div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64870&oldid=prevGipsonAndrew: /* Copper Bioleaching Techniques */2011-05-12T20:50:44Z<p><span dir="auto"><span class="autocomment">Copper Bioleaching Techniques</span></span></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Modern biomining processes are large-scale operations that involve the mining of ores and processing for several months. Either through strip-mining or blasting, raw ore is obtained.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Modern biomining processes are large-scale operations that involve the mining of ores and processing for several months <ins style="font-weight: bold; text-decoration: none;">(Fig. 1)</ins>. Either through strip-mining or blasting, raw ore is obtained.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64868&oldid=prevGipsonAndrew: /* Copper Bioleaching Techniques */2011-05-12T20:50:19Z<p><span dir="auto"><span class="autocomment">Copper Bioleaching Techniques</span></span></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=Copper Bioleaching Techniques=</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Rawlings 2002 Heap leaching of copper-containing ore.jpeg|thumb|350px|right|Figure 2. Outline of the heap leaching process. After irrigating the heap with a lixiviant, the copper-containing leach liquor is collected and processed by solvent extraction and electrowinning to yield copper metal. (Rawlings 2002)]]</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Modern biomining processes are large-scale operations that involve the mining of ores and processing for several months. Either through strip-mining or blasting, raw ore is obtained.</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Heap Irrigation===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ores obtained from mining are crushed and piled up to 10 meters high atop plastic irrigation pads, whereupon water seeded with acid, called the lixiviant, is irrigated through the heaps and collected (Fig. 2). After performing the next steps to extract the copper dissolved in the leach liquor, it is recycled and used to irrigate the heap again (Rawlings 2002).<br></div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64867&oldid=prevGipsonAndrew at 20:48, 12 May 20112011-05-12T20:48:38Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure #. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. #). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure #. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. #). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions and in the presence of certain toxic metals such as arsenic ''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates. Improvement of the nutrient conditions in the heap reactor can increase the ''At. ferrooxidans'' population, which can be achieved through the addition of phosphate (</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions and in the presence of certain toxic metals such as arsenic ''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates. Improvement of the nutrient conditions in the heap reactor can increase the ''At. ferrooxidans'' population, which can be achieved through the addition of phosphate (<ins style="font-weight: bold; text-decoration: none;">Varela ''et al.'' 1998).</ins></div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sugio T, Wakabayashi M, Kanao T, Takeuchi F (2008) Isolation and Characterization of Acidithiobacillus ferrooxidans Strain D3-2 Active in Copper Bioleaching from a Copper Mine in Chile. ''Biosci. Biotechnol. Biochem.'' '''72'''(4): 998–1004.<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sugio T, Wakabayashi M, Kanao T, Takeuchi F (2008) Isolation and Characterization of Acidithiobacillus ferrooxidans Strain D3-2 Active in Copper Bioleaching from a Copper Mine in Chile. ''Biosci. Biotechnol. Biochem.'' '''72'''(4): 998–1004.<br></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Valdés J, Pedroso I, Quatrini R, Dodson RJ, Tettelin H, Blake R, Eisen JA, Holmes DS (2008) Acidithiobacillus ferrooxidans metabolism: from genome sequence to industrial applications. ''BMC Genomics'' '''9''': 597.<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Valdés J, Pedroso I, Quatrini R, Dodson RJ, Tettelin H, Blake R, Eisen JA, Holmes DS (2008) Acidithiobacillus ferrooxidans metabolism: from genome sequence to industrial applications. ''BMC Genomics'' '''9''': 597.<br></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Varela P, Levican G, Rivera F, Jerez CA (1998) An immunological strategy to monitor in situ the phosphate starvation state in ''Thiobacillus ferrooxidans''. ''Applied and Environmental Microbio.'' '''64'''(12): 4990-4993.</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Edited by student of [mailto:slonczewski@kenyon.edu Joan Slonczewski] for [http://biology.kenyon.edu/courses/biol238/biol238syl10.html BIOL 238 Microbiology], 2011, [http://www.kenyon.edu/index.xml Kenyon College].</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Edited by student of [mailto:slonczewski@kenyon.edu Joan Slonczewski] for [http://biology.kenyon.edu/courses/biol238/biol238syl10.html BIOL 238 Microbiology], 2011, [http://www.kenyon.edu/index.xml Kenyon College].</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><!--Do not edit or remove this line-->[[Category:Pages edited by students of Joan Slonczewski at Kenyon College]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><!--Do not edit or remove this line-->[[Category:Pages edited by students of Joan Slonczewski at Kenyon College]]</div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64863&oldid=prevGipsonAndrew: /* Improving the Organism */2011-05-12T20:46:12Z<p><span dir="auto"><span class="autocomment">Improving the Organism</span></span></p>
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 20:46, 12 May 2011</td>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Organism===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure #. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. #). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:Sugio_et_al_2008_Solubilization_of_Cu2+_from_a_Chalcopyrite_Concentrate.png|thumb|350px|right|Figure #. Concentrations of copper solubilized from chalcopyrite in low-pH cultures of different <i>At. ferrooxidans</i> strains. White bar = 7 d after inoculation, gray bar = 14 d, and black bar = 30 d. (Sugio <i>et al.</i> 2008)]]A study done on the copper solubilizing activity of <i>At. ferrooxidans</i> strains isolated from a low-grade copper mine in Chile revealed that when grown in a chalcopyrite-containing medium, a particular strain called D3-2 had a greatly enhanced solubilizing activity in relation to other strains (Fig. #). The reason for this increased activity is connected to the D3-2 strain's resistance to sulfite (SO<sub>3</sub><sup>2-</sup>), a toxic intermediate in sulfur oxidation. Sulfite hinders the activity of iron oxidase, an important enzyme in the bacterium's iron oxidation pathway which provides ferric ions for the solubilization of sulfides (Sugio <i>et al.</i> 1994). Most organisms including <i>At. ferrooxidans</i> possess a sulfite oxidase enzyme that converts sulfite to sulfate under low sulfite conditions (Feng ''et al.'' 2007), but this activity tends to be inhibited at higher concentrations. However, the D3-2 strain has a sulfite reductase that is more resistant to sulfite and thus can oxidize it faster, resulting in a lowered sulfite concentration that doesn't inhibit the iron oxidation pathway (Sugio <i>et al.</i> 2008).<br></div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"><br></del>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions<del style="font-weight: bold; text-decoration: none;">, </del>''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One cause for concern regarding the efficiency of the process in regards to the organism is the makeup of the microbial community in a heap reactor. Studies on the composition of the bacterial community have showed that under lower-nutrient conditions <ins style="font-weight: bold; text-decoration: none;">and in the presence of certain toxic metals such as arsenic </ins>''At. ferrooxidans'' is not the majority member, but rather non-iron oxidizing bacteria such as ''Thiobacillus caldus'' (Rawlings ''et al.'' 1999). This is problematic because the metabolic activities of these other species do not produce the ferric ions responsible for solubilizing copper sulfates. <ins style="font-weight: bold; text-decoration: none;">Improvement of the nutrient conditions in the heap reactor can increase the ''At. ferrooxidans'' population, which can be achieved through the addition of phosphate (</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Improving the Process===</div></td></tr>
</table>GipsonAndrewhttps://microbewiki.kenyon.edu/index.php?title=Copper_Mining_Using_Acidothiobacillus&diff=64856&oldid=prevGipsonAndrew at 20:39, 12 May 20112011-05-12T20:39:01Z<p></p>
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 20:39, 12 May 2011</td>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Leduc LG and Ferroni GD (1994) The chemolithotrophic bacterium ''Thiobacillus ferrooxidans''. ''FEMS Microbiology Reviews'' '''14''':103-120.<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Leduc LG and Ferroni GD (1994) The chemolithotrophic bacterium ''Thiobacillus ferrooxidans''. ''FEMS Microbiology Reviews'' '''14''':103-120.<br></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://journals.ohiolink.edu/ejc/pdf.cgi/Mignone_C.F.pdf?issn=1369703x&issue=v18i0003&article=211_arfgamoib Mignone CF and Donati ER (2004) ATP requirements for growth and maintenance of iron-oxidizing bacteria. ''Biochemical Engineering Journal'' '''18''': 211–216.]<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://journals.ohiolink.edu/ejc/pdf.cgi/Mignone_C.F.pdf?issn=1369703x&issue=v18i0003&article=211_arfgamoib Mignone CF and Donati ER (2004) ATP requirements for growth and maintenance of iron-oxidizing bacteria. ''Biochemical Engineering Journal'' '''18''': 211–216.]<br></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Rawlings DE, Coram NJ, Gardner MN, Deane SM (1999) ''Thiobacillus caldus'' and ''Leptospirillum ferrooxidans'' are widely distributed in continuous flow biooxidation tanks used to treat a variety of metal containing ores and concentrates. In ''Biohydrometallurgy and the Environment Towards the 21st Century. Part A'', ed. Amils R and Ballester A. 777-786. Amsterdam: Elsevier<br></ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.annualreviews.org/doi/full/10.1146/annurev.micro.56.012302.161052?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed& Rawlings DE (2002) Heavy metal mining using microbes. ''Annu. Rev. Microbiol.'' '''56''': 65-91.]<br></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[http://www.annualreviews.org/doi/full/10.1146/annurev.micro.56.012302.161052?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed& Rawlings DE (2002) Heavy metal mining using microbes. ''Annu. Rev. Microbiol.'' '''56''': 65-91.]<br></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sand W and Gehrke T (2006) Extracellular polymeric substances mediate bioleaching/biocorrosion via</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Sand W and Gehrke T (2006) Extracellular polymeric substances mediate bioleaching/biocorrosion via</div></td></tr>
</table>GipsonAndrew