scholarly journals Sulfur Oxygenase Reductase (Sor) in the Moderately Thermoacidophilic Leaching Bacteria: Studies in Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus

2015 ◽  
Vol 3 (4) ◽  
pp. 707-724 ◽  
Author(s):  
Claudia Janosch ◽  
Francisco Remonsellez ◽  
Wolfgang Sand ◽  
Mario Vera
2009 ◽  
Vol 71-73 ◽  
pp. 239-242 ◽  
Author(s):  
Claudia Janosch ◽  
Christian Thyssen ◽  
Mario A. Vera ◽  
Violaine Bonnefoy ◽  
Thore Rohwerder ◽  
...  

The elemental sulfur oxidising enzyme Sulfur Oxygenase Reductase (SOR) is very well investigated in acidothermophilic archaea, such as Acidianus brierleyi and Sulfolobus metallicus. In contrast, not much is known about the biochemistry of elemental sulfur oxidation in acidophilic bacteria. Recently, however, the SOR-encoding gene has been found also in a bacterial strain closely related to the moderate thermophile Acidithiobacillus caldus. Confusingly, for the latter species, also the involvement of the SOX system as well as thiosulfate:quinone oxidoreductase (TQO) and tetrathionate hydrolase (TTH) in sulfur compound oxidation has been proposed based on genome analysis. In this study, we have detected the sor-gene in other Acidithiobacillus caldus-like strains, isolated from various bioleaching habitats, indicating that SOR plays an important role in sulfur oxidation in this species. Based on sequence comparison, the new bacterial sor-genes are closely related and distant from the known archaeal sequences as well as from the SOR found in the neutrophilic bacterium Aquifex aeolicus. In addition, SOR activity has been detected in crude cell extracts from all Acidithiobacillus caldus-like strains tested. The enzyme is truly thermophilic as highest activities were achieved at 65 °C, which is far beyond the growth optimum of Acidithiobacillus caldus. This finding may give rise to the question whether the presence of SOR in Acidithiobacillus caldus is only relevant while growing at elevated temperatures. Currently, experiments are performed for testing this hypothesis (comparing growth and enzyme activities at 30 vs. 45 °C).


2018 ◽  
Vol 777 ◽  
pp. 277-281
Author(s):  
He Shang ◽  
Biao Wu ◽  
Jian Kang Wen ◽  
Xing Lan Cui

High-throughput sequencing technology also known as "next generation" sequencing technology, compared with the traditional sequencing method has the characteristics of fast speed, high flux, low cost. In recent years the technology in the detection of microbial diversity has been fully applied. In this study, the microbial community of ore heap in different area and different depth was studied by using this method. The results showed the bio - heap leaching of low - grade secondary copper sulfide ore in Zijinshan from China could effectively recover the copper in the ore. The number of microorganisms in the center was significantly larger than that on the edge of ore heap, and as the depth increases in the heap, the number of microorganisms decreases. The dominant bacteria in the ore heap center was Acidithiobacillus ferrooxidans, in addition there were also some Sulfobacillus thermosulfidooxidans, Ferroplasma cupricumulans, Acidithiobacillus caldus and a small amount of Leptospirillum ferriphilum in the center of the ore heap. Unlike the ore heap center, Sulfobacillus thermosulfidooxidans was the main species on the edge of the ore heap, moreover Acidithiobacillus ferrooxidans, Ferroplasma cupricumulans, Acidithiobacillus caldus and a small amount of Leptospirillum ferriphilum were found on the edge of the ore heap. In addition, some heterotrophic bacteria such as Pseudomonas, Serratia, Sediminibacterium, Stenotrophomonas, Brevundimonas and Variovorax were found both in the center and the edge of the sample, these heterotrophic bacteria may be beneficial for the leaching of valuable metals.


2013 ◽  
Vol 825 ◽  
pp. 472-476 ◽  
Author(s):  
Wen Qing Qin ◽  
Cong Ren Yang ◽  
Jun Wang ◽  
Yansheng Zhang ◽  
Fen Jiao ◽  
...  

The electrochemical behavior of massive chalcopyrite in presence of Acidithiobacillus caldus, Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans and Sulfobacillus thermosulfidooxidans has been studied by cyclic voltammetry. The effect of Fe2+ and Cu2+ ion addition on the electrochemical behavior of massive chalcopyrite in bioleaching system were also investigated. The voltammograms illustrated that current densities of peaks were obviously increased with adding Fe2+ into the electrolyte. A series of anodic peaks were observed at more than 0 V when adding Fe2+ and Cu2+ ions, and these peaks are similar to the peaks of the step oxidation of chalcocite, thus proving that the formation of intermediate CuS2. Especially, the 9 g/L Fe2+ and 1.5 g/L Cu2+ were added. Therefore, appropriate ferrous and cupric ions concentration could enhance the formation of intermediate CuS2 leading to accelerate dissolution of chalcopyrite.


2013 ◽  
Vol 825 ◽  
pp. 107-110
Author(s):  
Sören Bellenberg ◽  
Robert Barthen ◽  
Mario Vera ◽  
Nicolas Guiliani ◽  
Wolfgang Sand

A functional luxIR-type Quorum Sensing (QS) system is present in Acidithiobacillus ferrooxidans. However, cell-cell communication among various acidophilic chemolithoautotrophs growing on pyrite has not been studied in detail. These aspects are the scope of this study with emphasis on the effects exerted by the N-acyl-homoserine lactone (AHL) type signaling molecules which are produced by Acidithiobacillus ferrooxidans. Their effects on attachment and leaching efficiency by other leaching bacteria, such as Acidithiobacillus ferrivorans, Acidiferrobacter spp. SPIII/3 and Leptospirillum ferrooxidans in pure and mixed cultures growing on pyrite is shown.


2012 ◽  
Vol 524-527 ◽  
pp. 1997-2003
Author(s):  
Hai Yun Xie ◽  
Zhuo Yue Lan ◽  
Shu Ming He ◽  
Li Kun Gao ◽  
Xiong Tong

The usage of high-arsenic sulfide copper concentrate were limited because the arsenic in the concentrate harms the qualities of copper product and pollutes the environment. In this paper an innovative process for high-arsenic copper sulfide concentrate with with bio-oxidation respectively Thiobacillus ferrooxidans and moderate thermophile Sulfobacillus thermosulfidooxidans has been studied out, and the influencing factors have been comparative studied during the leaching process, such as concentration particle size, leaching methods, pulp concentration, leaching time and the initial concentration of Fe3+, etc. Under the suitable leaching conditions, the experiments results show that the concentrate is leached 47.13% of Cu,50.09% of As and 52.46% of Fe by Thiobacillus ferrooxidans and 82.39% of Cu,78.21% of As and 40.38% of Fe by moderate thermophile Sulfobacillus thermosulfidooxidans. The high concentration initial Fe3+ has speeded leaching process up in the presence of moderate thermophile Sulfobacillus thermosulfidooxidans, and when the pulp initial concentration of Fe3+ is in the range of 0.08~0.32mol/L, the leaching rate of Cu is 86.34~97.06%, As 89.22~94.13%. It is concluded that Sulfobacillus thermosulfidooxidans have a better effect on bioleaching high-arsenic sulfide copper concentrate than Thiobacillus ferrooxidans.


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