Adhesion forces between cells of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans or Leptospirillum ferrooxidans and chalcopyrite

2012 ◽  
Vol 94 ◽  
pp. 95-100 ◽  
Author(s):  
Jianyu Zhu ◽  
Qian Li ◽  
Weifeng Jiao ◽  
Hao Jiang ◽  
Wolfgang Sand ◽  
...  
Respuestas ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 72-83
Author(s):  
Lina M. Miranda Arroyave ◽  
Marco Antonio Márquez Godoy ◽  
Luz Marina Ocampo Carmona

One of the main characteristics of the microorganisms used in the leaching process is their capacity to adapt to aggressive environments, characterized by a notable presence of heavy metals. In this study the adaptation of the strains Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans was evaluated on a sphalerite concentrate from mining waste. In the adaptation tests, the energy source (ferrous sulphate) was gradually replaced by percentages of mineral pulp, ending with subcultures without the addition of an external energy source. The results show that the strains A. ferrooxidans and A. thiooxidans are more resistant to high concentrations of sphalerite, compared to the strain of L. ferrooxidans, since, in the case of this strain, it was necessary to repeat some tests (8% of pulp), since a deficient development was evident. This was associated with factors such as the decrease of the Fe+2 energy source, the increase of the pulp density, the accumulation of toxic metals and secondary products of the dissolution of minerals and the increase of the pH.


Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 653 ◽  
Author(s):  
Mohammad Jafari ◽  
Mehdi Golzadeh ◽  
Sied Shafaei ◽  
Hadi Abdollahi ◽  
Mahdi Gharabaghi ◽  
...  

Bioleaching is an environment-friendly and low-investment process for the extraction of metals from flotation concentrate. Surfactants such as collectors and frothers are widely used in the flotation process. These chemical reagents may have inhibitory effects on the activity of microorganisms through a bioleaching process; however, there is no report indicating influences of reagents on the activity of microorganisms in the mixed culture which is mostly used in the industry. In this investigation, influences of typical flotation frothers (methyl isobutyl carbinol and pine oil) in different concentrations (0.01, 0.10, and 1.00 g/L) were examined on activates of bacteria in the mesophilic mixed culture (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Acidithiobacillus thiooxidans). For comparison purposes, experiments were repeated by pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans in the same conditions. Results indicated that increasing the dosage of frothers has a negative correlation with bacteria activities while the mixed culture showed a lower sensitivity to the toxicity of these frothers in comparison with examined pure cultures. Outcomes showed the toxicity of Pine oil is lower than methyl isobutyl carbinol (MIBC). These results can be used for designing flotation separation procedures and to produce cleaner products for bio extraction of metals.


Author(s):  
Gerardo Andrés Caicedo Pineda ◽  
Marco Antonio Márquez Godoy

<p>Se llevaron a cabo procesos de biodesulfurización de dos carbones colombianos ricos en azufre (“Mina Vieja” y “Vampiro”), en reactores de lecho empacado a nivel de erlenmeyer, utilizando un consorcio de Acidithiobacillus ferrooxidans (ATCC 23270) y Acidithiobacillus thiooxidans (ATCC 15494), evaluando la adición de cisteína a la solución lixiviante. Los ensayos fueron monitoreados por medidas de hierro en solución, pH y potencial redox. Adicionalmente, se hicieron análisis mineralógicos por difracción de rayos X (DRX) antes y después de los experimentos. Los ensayos sin adición de cisteína alcanzaron una oxidación de pirita de 45.3% y 57.9% para “Mina Vieja” y “Vampiro” respectivamente. Cuando se adicionó cisteína, la oxidación aumentó en 14.9% para “Mina Vieja” y 6.4% para “Vampiro”. Por otra parte, todos los ensayos evidenciaron remoción de caolinita, debido a su interacción con el ácido sulfúrico del medio. Con base en los resultados obtenidos, los componentes del carbón influenciaron tanto crecimiento bacteriano como la eficiencia de la cisteína sobre el grado de pirita oxidada.</p>


2008 ◽  
Vol 92 (3-4) ◽  
pp. 102-106 ◽  
Author(s):  
Blanca Escobar ◽  
Karina Bustos ◽  
Gabriela Morales ◽  
Oriana Salazar

2012 ◽  
Vol 512-515 ◽  
pp. 2500-2504 ◽  
Author(s):  
Yu Yang ◽  
Gai Mei Ren ◽  
Xiang Wang ◽  
Li Yang

The removal of sulfur in coal before its combustion can reduce its environmental pollution, and microbial desulfurization should have good application prospects. Some species of bacteria have been used in the process of coal desulfurization, and our previous study demonstrated that mixed culture should be more efficient than pure culture by shaking cultivation. In this study, column leaching was investigated, due to its similarity to the industrial heap leaching. The mixed culture consisted of three strains of bacteria, which were Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans respectively. The ratio of the three strains of bacteria was 1: 1: 1. The column (50 cm height, 650 mm Inner Diameter) bioleaching experiments were carried out at ambient temperature. After desulfurization for 18 days, the ultimate desulfurization rate was 28.66% for total sulfur, which was higher than the previous study of J.Cara (with total sulfur desulfurization rate for 24% after 125 days). This study showed that ferric ions should be in proper concentration, and Leptospirillum ferrooxidans might be in lower ratio for reducing the precipitation of jarosite and improving the efficient of coal desulfurization.


Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 406 ◽  
Author(s):  
Qian Li ◽  
Baojun Yang ◽  
Jianyu Zhu ◽  
Hao Jiang ◽  
Jiaokun Li ◽  
...  

Adhesion plays an important role in bacterial dissolution of metal sulfides, since the attached cells initiate the dissolution. In addition, biofilms, forming after bacterial attachment, enhance the dissolution. In this study, interactions between initial adhesion force, attachment behavior and copper recovery were comparatively analyzed for Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferrooxidans during bioleaching of chalcopyrite. The adhesion forces between bacteria and minerals were measured by atomic force microscopy (AFM). L. ferrooxidans had the largest adhesion force and attached best to chalcopyrite, while A. ferrooxidans exhibited the highest bioleaching of chalcopyrite. The results suggest that the biofilm formation, rather than the initial adhesion, is positively correlated with bioleaching efficiency.


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