From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems
In the actual mining scenario, copper bioleaching, mainly raw mined material known as run-of-mine (ROM) copper bioleaching, is the best alternative for the treatment of marginal resources that are not currently considered part of the profitable reserves because of the cost associated with leading te...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-03-01
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| Series: | Genes |
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| Online Access: | https://www.mdpi.com/2073-4425/12/4/474 |
| _version_ | 1797540007847657472 |
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| author | Sabrina Marín Mayra Cortés Mauricio Acosta Karla Delgado Camila Escuti Diego Ayma Cecilia Demergasso |
| author_facet | Sabrina Marín Mayra Cortés Mauricio Acosta Karla Delgado Camila Escuti Diego Ayma Cecilia Demergasso |
| author_sort | Sabrina Marín |
| collection | DOAJ |
| description | In the actual mining scenario, copper bioleaching, mainly raw mined material known as run-of-mine (ROM) copper bioleaching, is the best alternative for the treatment of marginal resources that are not currently considered part of the profitable reserves because of the cost associated with leading technologies in copper extraction. It is foreseen that bioleaching will play a complementary role in either concentration—as it does in Minera Escondida Ltd. (MEL)—or chloride main leaching plants. In that way, it will be possible to maximize mines with installed solvent-extraction and electrowinning capacities that have not been operative since the depletion of their oxide ores. One of the main obstacles for widening bioleaching technology applications is the lack of knowledge about the key events and the attributes of the technology’s critical events at the industrial level and mainly in ROM copper bioleaching industrial operations. It is relevant to assess the bed environment where the bacteria–mineral interaction occurs to learn about the limiting factors determining the leaching rate. Thus, due to inability to accurately determine in-situ key variables, their indirect assessment was evaluated by quantifying microbial metabolic-associated responses. Several candidate marker genes were selected to represent the predominant components of the microbial community inhabiting the industrial heap and the metabolisms involved in microbial responses to changes in the heap environment that affect the process performance. The microbial community’s predominant components were <i>Acidithiobacillus ferrooxidans</i>, <i>At. thiooxidans</i>, <i>Leptospirillum ferriphilum</i>, and <i>Sulfobacillus</i> sp. Oxygen reduction, CO<sub>2</sub> and N<sub>2</sub> fixation/uptake, iron and sulfur oxidation, and response to osmotic stress were the metabolisms selected regarding research results previously reported in the system. After that, qPCR primers for each candidate gene were designed and validated. The expression profile of the selected genes vs. environmental key variables in pure cultures, column-leaching tests, and the industrial bioleaching heap was defined. We presented the results obtained from the industrial validation of the marker genes selected for assessing CO<sub>2</sub> and N<sub>2</sub> availability, osmotic stress response, as well as ferrous iron and sulfur oxidation activity in the bioleaching heap process of MEL. We demonstrated that molecular markers are useful for assessing limiting factors like nutrients and air supply, and the impact of the quality of recycled solutions. We also learned about the attributes of variables like CO<sub>2</sub>, ammonium, and sulfate levels that affect the industrial ROM-scale operation. |
| first_indexed | 2024-03-10T12:53:57Z |
| format | Article |
| id | doaj.art-2a0e1089e9134870a0aacf14dfd73c2b |
| institution | Directory Open Access Journal |
| issn | 2073-4425 |
| language | English |
| last_indexed | 2024-03-10T12:53:57Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Genes |
| spelling | doaj.art-2a0e1089e9134870a0aacf14dfd73c2b2023-11-21T12:03:12ZengMDPI AGGenes2073-44252021-03-0112447410.3390/genes12040474From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching SystemsSabrina Marín0Mayra Cortés1Mauricio Acosta2Karla Delgado3Camila Escuti4Diego Ayma5Cecilia Demergasso6Centro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileCentro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileCentro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileCentro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileCentro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileDepartamento de Matemáticas, Facultad de Ciencias, Universidad Católica del Norte, Antofagasta 1240000, ChileCentro de Biotecnología, Universidad Católica del Norte, Antofagasta 1240000, ChileIn the actual mining scenario, copper bioleaching, mainly raw mined material known as run-of-mine (ROM) copper bioleaching, is the best alternative for the treatment of marginal resources that are not currently considered part of the profitable reserves because of the cost associated with leading technologies in copper extraction. It is foreseen that bioleaching will play a complementary role in either concentration—as it does in Minera Escondida Ltd. (MEL)—or chloride main leaching plants. In that way, it will be possible to maximize mines with installed solvent-extraction and electrowinning capacities that have not been operative since the depletion of their oxide ores. One of the main obstacles for widening bioleaching technology applications is the lack of knowledge about the key events and the attributes of the technology’s critical events at the industrial level and mainly in ROM copper bioleaching industrial operations. It is relevant to assess the bed environment where the bacteria–mineral interaction occurs to learn about the limiting factors determining the leaching rate. Thus, due to inability to accurately determine in-situ key variables, their indirect assessment was evaluated by quantifying microbial metabolic-associated responses. Several candidate marker genes were selected to represent the predominant components of the microbial community inhabiting the industrial heap and the metabolisms involved in microbial responses to changes in the heap environment that affect the process performance. The microbial community’s predominant components were <i>Acidithiobacillus ferrooxidans</i>, <i>At. thiooxidans</i>, <i>Leptospirillum ferriphilum</i>, and <i>Sulfobacillus</i> sp. Oxygen reduction, CO<sub>2</sub> and N<sub>2</sub> fixation/uptake, iron and sulfur oxidation, and response to osmotic stress were the metabolisms selected regarding research results previously reported in the system. After that, qPCR primers for each candidate gene were designed and validated. The expression profile of the selected genes vs. environmental key variables in pure cultures, column-leaching tests, and the industrial bioleaching heap was defined. We presented the results obtained from the industrial validation of the marker genes selected for assessing CO<sub>2</sub> and N<sub>2</sub> availability, osmotic stress response, as well as ferrous iron and sulfur oxidation activity in the bioleaching heap process of MEL. We demonstrated that molecular markers are useful for assessing limiting factors like nutrients and air supply, and the impact of the quality of recycled solutions. We also learned about the attributes of variables like CO<sub>2</sub>, ammonium, and sulfate levels that affect the industrial ROM-scale operation.https://www.mdpi.com/2073-4425/12/4/474acidophilic bacteriametabolic monitoringheap leachingdecision makingrelative gene expressiongenetic markers |
| spellingShingle | Sabrina Marín Mayra Cortés Mauricio Acosta Karla Delgado Camila Escuti Diego Ayma Cecilia Demergasso From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems Genes acidophilic bacteria metabolic monitoring heap leaching decision making relative gene expression genetic markers |
| title | From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems |
| title_full | From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems |
| title_fullStr | From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems |
| title_full_unstemmed | From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems |
| title_short | From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems |
| title_sort | from laboratory towards industrial operation biomarkers for acidophilic metabolic activity in bioleaching systems |
| topic | acidophilic bacteria metabolic monitoring heap leaching decision making relative gene expression genetic markers |
| url | https://www.mdpi.com/2073-4425/12/4/474 |
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