Sulfur Oxygenase Reductase in Different Acidithiobacillus Caldus-Like Strains

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).

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Insight into the Sulfur Metabolism by Thermoacidophilic Archaeon Metallosphaera cuprina with Genomic, Proteomic and Biochemical Tools

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1130.145 ◽

2015 ◽

Vol 1130 ◽

pp. 145-148 ◽

Cited By ~ 4

Author(s):

Jin Long Song ◽

Cheng Ying Jiang ◽

Shuang Jiang Liu

Keyword(s):

Transfer Reaction ◽

Elemental Sulfur ◽

Hot Spring ◽

Sulfur Metabolism ◽

Genomic Data ◽

Sulfur Oxidation ◽

Low Grade ◽

Hypothetical Model ◽

Insight Into ◽

Sulfur Oxygenase Reductase

Abstract. The thermoacidophilic archaeon Metallosphaeracuprina was isolated from a sulfuric hot spring. M. cuprina is able to oxidize elemental sulfur, tetrathionate (S4O62+) pyrite, and a range of low-grade ores, thus is attractive to biomining industry. Dissimilatory sulfur metabolism with a sulfur oxygenase reductase (SOR) system has been reported for members of Sulfolobus and Acidianus. But SOR system was not identified in the genome of M. cuprina. Recently, we have explored the sulfur metabolism of M. cuprina with genomic, proteomic, and biochemical tools. A hypothetical model of sulfur metabolism in M. cuprina was proposed on proteomic and genomic data, and proteins that involved in sulfur metabolism have been identified in our following studies. Specifically, DsrE/TusA homologs were biochemically characterized, and a novel thiosulfate transfer reaction was found during sulfur oxidation with M. cuprina. More recently, we cloned and identified a CoA-dependent NAD(P)H sulfur oxidoreductase from M.cuprina. The study will cover new understandings of the sulfur metabolism with M. cuprina.

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Acidithiobacillus caldus Sulfur Oxidation Model Based on Transcriptome Analysis between the Wild Type and Sulfur Oxygenase Reductase Defective Mutant

PLoS ONE ◽

10.1371/journal.pone.0039470 ◽

2012 ◽

Vol 7 (9) ◽

pp. e39470 ◽

Cited By ~ 66

Author(s):

Linxu Chen ◽

Yilin Ren ◽

Jianqun Lin ◽

Xiangmei Liu ◽

Xin Pang ◽

...

Keyword(s):

Transcriptome Analysis ◽

Sulfur Oxidation ◽

Wild Type ◽

Model Based ◽

Acidithiobacillus Caldus ◽

Defective Mutant ◽

Oxidation Model ◽

Sulfur Oxygenase Reductase

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Distribution, Diversity, and Activities of Sulfur Dioxygenases in Heterotrophic Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.03281-13 ◽

2014 ◽

Vol 80 (5) ◽

pp. 1799-1806 ◽

Cited By ~ 28

Author(s):

Honglei Liu ◽

Yufeng Xin ◽

Luying Xun

Keyword(s):

Elemental Sulfur ◽

Heterotrophic Bacteria ◽

Sulfur Oxidation ◽

Wide Distribution ◽

Content Type ◽

Ethylmalonic Encephalopathy ◽

Cell Extracts ◽

Gene Coding ◽

Chemolithotrophic Bacteria ◽

Specific Activities

ABSTRACTSulfur oxidation by chemolithotrophic bacteria is well known; however, sulfur oxidation by heterotrophic bacteria is often ignored. Sulfur dioxygenases (SDOs) (EC 1.13.11.18) were originally found in the cell extracts of some chemolithotrophic bacteria as glutathione (GSH)-dependent sulfur dioxygenases. GSH spontaneously reacts with elemental sulfur to generate glutathione persulfide (GSSH), and SDOs oxidize GSSH to sulfite and GSH. However, SDOs have not been characterized for bacteria, including chemolithotrophs. The gene coding for human SDO (human ETHE1 [hETHE1]) in mitochondria was discovered because its mutations lead to a hereditary human disease, ethylmalonic encephalopathy. Using sequence analysis and activity assays, we discovered three subgroups of bacterial SDOs in the proteobacteria and cyanobacteria. Ten selected SDO genes were cloned and expressed inEscherichia coli, and the recombinant proteins were purified. The SDOs used Fe2+for catalysis and displayed considerable variations in specific activities. The wide distribution of SDO genes reveals the likely source of the hETHE1 gene and highlights the potential of sulfur oxidation by heterotrophic bacteria.

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Distinct Roles of Acidophiles in Complete Oxidation of High-Sulfur Ferric Leach Product of Zinc Sulfide Concentrate

Microorganisms ◽

10.3390/microorganisms8030386 ◽

2020 ◽

Vol 8 (3) ◽

pp. 386 ◽

Cited By ~ 3

Author(s):

Maxim Muravyov ◽

Anna Panyushkina

Keyword(s):

Microbial Community ◽

Zinc Sulfide ◽

Elemental Sulfur ◽

Waste Product ◽

Sulfur Oxidation ◽

Low Grade ◽

Sulfide Concentrates ◽

Sulfide Concentrate ◽

Elemental Sulfur Oxidation ◽

Ferric Leaching

A two-step process, which involved ferric leaching with biologically generated solution and subsequent biooxidation with the microbial community, has been previously proposed for the processing of low-grade zinc sulfide concentrates. In this study, we carried out the process of complete biological oxidation of the product of ferric leaching of the zinc concentrate, which contained 9% of sphalerite, 5% of chalcopyrite, and 29.7% of elemental sulfur. After 21 days of biooxidation at 40 °C, sphalerite and chalcopyrite oxidation reached 99 and 69%, respectively, while the level of elemental sulfur oxidation was 97%. The biooxidation residue could be considered a waste product that is inert under aerobic conditions. The results of this study showed that zinc sulfide concentrate processing using a two-step treatment is efficient and promising. The microbial community, which developed during biooxidation, was dominated by Acidithiobacillus caldus, Leptospirillum ferriphilum, Ferroplasma acidiphilum, Sulfobacillus thermotolerans, S. thermosulfidooxidans, and Cuniculiplasma sp. At the same time, F. acidiphilum and A. caldus played crucial roles in the oxidation of sulfide minerals and elemental sulfur, respectively. The addition of L. ferriphilum to A. caldus during biooxidation of the ferric leach product proved to inhibit elemental sulfur oxidation.

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Groundwater cable bacteria conserve energy by sulfur disproportionation

The ISME Journal ◽

10.1038/s41396-019-0554-1 ◽

2019 ◽

Vol 14 (2) ◽

pp. 623-634 ◽

Cited By ~ 7

Author(s):

Hubert Müller ◽

Sviatlana Marozava ◽

Alexander J. Probst ◽

Rainer U. Meckenstock

Keyword(s):

16S Rrna ◽

Electron Donor ◽

Nitrate Reduction ◽

Elemental Sulfur ◽

Single Cells ◽

Sulfur Oxidation ◽

Metabolic Reconstruction ◽

Rrna Gene ◽

Long Distance ◽

Sulfur Disproportionation

AbstractCable bacteria of the family Desulfobulbaceae couple spatially separated sulfur oxidation and oxygen or nitrate reduction by long-distance electron transfer, which can constitute the dominant sulfur oxidation process in shallow sediments. However, it remains unknown how cells in the anoxic part of the centimeter-long filaments conserve energy. We found 16S rRNA gene sequences similar to groundwater cable bacteria in a 1-methylnaphthalene-degrading culture (1MN). Cultivation with elemental sulfur and thiosulfate with ferrihydrite or nitrate as electron acceptors resulted in a first cable bacteria enrichment culture dominated >90% by 16S rRNA sequences belonging to the Desulfobulbaceae. Desulfobulbaceae-specific fluorescence in situ hybridization (FISH) unveiled single cells and filaments of up to several hundred micrometers length to belong to the same species. The Desulfobulbaceae filaments also showed the distinctive cable bacteria morphology with their continuous ridge pattern as revealed by atomic force microscopy. The cable bacteria grew with nitrate as electron acceptor and elemental sulfur and thiosulfate as electron donor, but also by sulfur disproportionation when Fe(Cl)2 or Fe(OH)3 were present as sulfide scavengers. Metabolic reconstruction based on the first nearly complete genome of groundwater cable bacteria revealed the potential for sulfur disproportionation and a chemo-litho-autotrophic metabolism. The presence of different types of hydrogenases in the genome suggests that they can utilize hydrogen as alternative electron donor. Our results imply that cable bacteria not only use sulfide oxidation coupled to oxygen or nitrate reduction by LDET for energy conservation, but sulfur disproportionation might constitute the energy metabolism for cells in large parts of the cable bacterial filaments.

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

Microorganisms ◽

10.3390/microorganisms3040707 ◽

2015 ◽

Vol 3 (4) ◽

pp. 707-724 ◽

Cited By ~ 14

Author(s):

Claudia Janosch ◽

Francisco Remonsellez ◽

Wolfgang Sand ◽

Mario Vera

Keyword(s):

Acidithiobacillus Caldus ◽

Sulfobacillus Thermosulfidooxidans ◽

Leaching Bacteria ◽

Sulfur Oxygenase Reductase

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Kinetic Constant Variability in Bacterial Oxidation of Elemental Sulfur

Applied and Environmental Microbiology ◽

10.1128/aem.02549-06 ◽

2007 ◽

Vol 73 (11) ◽

pp. 3752-3754 ◽

Cited By ~ 18

Author(s):

Blanka Pokorna ◽

Martin Mandl ◽

Sarka Borilova ◽

Pavla Ceskova ◽

Romana Markova ◽

...

Keyword(s):

Acidithiobacillus Ferrooxidans ◽

Elemental Sulfur ◽

Kinetic Constant ◽

Sulfur Oxidation ◽

Growth Yields ◽

Resting Cells ◽

Michaelis Constant ◽

Bacterial Oxidation ◽

Batch Cultures ◽

Oxidation Rates

ABSTRACT Wide ranges of growth yields on sulfur (from 2.4 × 1010 to 8.1 × 1011 cells g−1) and maximum sulfur oxidation rates (from 0.068 to 1.30 mmol liter−1 h−1) of an Acidithiobacillus ferrooxidans strain (CCM 4253) were observed in 73 batch cultures. No significant correlation between the constants was observed. Changes of the Michaelis constant for sulfur (from 0.46 to 15.5 mM) in resting cells were also noted.

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