scholarly journals Homologs from sulfur oxidation (Sox) and methanol dehydrogenation (Xox) enzyme systems collaborate to give rise to a novel pathway of chemolithotrophic tetrathionate oxidation

2018 ◽  
Vol 109 (2) ◽  
pp. 169-191 ◽  
Author(s):  
Prosenjit Pyne ◽  
Masrure Alam ◽  
Moidu Jameela Rameez ◽  
Subhrangshu Mandal ◽  
Abhijit Sar ◽  
...  
Keyword(s):  
Sulfur Oxidation ◽  
Methanol Dehydrogenation ◽  
Enzyme Systems ◽  
Tetrathionate Oxidation

scholarly journals Two pathways for thiosulfate oxidation in the alphaproteobacterial chemolithotrophParacoccus thiocyanatusSST

2019 ◽  
Author(s):  
Moidu Jameela Rameez ◽  
Prosenjit Pyne ◽  
Subhrangshu Mandal ◽  
Sumit Chatterjee ◽  
Masrure Alam ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Sulfur Oxidation ◽  
Substrate Affinity ◽  
No Production ◽  
Direct Oxidation ◽  
Knock Out ◽  
Thiosulfate Oxidation ◽  
Multienzyme System ◽  
Chemolithotrophic Bacteria ◽  
Tetrathionate Oxidation

AbstractChemolithotrophic bacteria oxidize various sulfur species for energy and electrons, thereby operationalizing biogeochemical sulfur cycles in nature. The best-studied pathway of bacterial sulfur-chemolithotrophy, involving direct oxidation of thiosulfate to sulfate (without any free intermediate) by the SoxXAYZBCD multienzyme system, is apparently the exclusive mechanism of thiosulfate oxidation in facultatively chemolithotrophic alphaproteobacteria. Here we explore the molecular mechanisms of sulfur oxidation in the thiosulfate- and tetrathionate-oxidizing alphaproteobacteriumParacoccus thiocyanatusSST, and compare them with the prototypical Sox process characterized inParacoccus pantotrophus. Our results revealed the unique case where, an alphaproteobacterium has Sox as its secondary pathway of thiosulfate oxidation, converting ∼10% of the thiosulfate supplied whilst 90% of the substrate is oxidized via a Tetrathionate-Intermediate pathway. Knock-out mutation, followed by the study of sulfur oxidation kinetics, showed that thiosulfate-to-tetrathionate conversion, in SST, is catalyzed by a thiosulfate dehydrogenase (TsdA) homolog that has far-higher substrate-affinity than the Sox system of this bacterium, which, remarkably, is also less efficient than theP. pantotrophusSox.soxB-deletion in SST abolished sulfate-formation from thiosulfate/tetrathionate while thiosulfate-to-tetrathionate conversion remained unperturbed. Physiological studies revealed the involvement of glutathione in SST tetrathionate oxidation. However, zero impact of the knock-out of a thiol dehydrotransferase (thdT) homolog, together with no production of sulfite as an intermediate, indicated that tetrathionate oxidation in SST is mechanistically novel, and distinct from its betaproteobacterial counterpart mediated by glutathione, ThdT, SoxBCD and sulfite:acceptor oxidoreductase. All the present findings collectively highlight extensive functional diversification of sulfur-oxidizing enzymes across phylogenetically close, as well as distant, bacteria.

scholarly journals Molecular mechanism of sulfur chemolithotrophy in the betaproteobacterium Pusillimonas ginsengisoli

2019 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Moidu Jameela Rameez ◽  
Prosenjit Pyne ◽  
Sabyasachi Bhattacharya ◽  
Jagannath Sarkar ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Genome Sequencing ◽  
Consumption Rate ◽  
Sulfur Oxidation ◽  
Whole Genome ◽  
Wild Type ◽  
Knock Out ◽  
Whole Cells ◽  
Sulfur Oxidizing ◽  
Tetrathionate Oxidation

AbstractMolecular mechanism of chemolithotrophic sulfur oxidation in Betaproteobacteria is less explored than that in Alphaproteobacteria. Here we carried out whole genome sequencing and analysis of a new betaproteobacterial isolate Pusillimonas ginsengisoli SBSA which oxidizes thiosulfate via formation tetrathionate as an intermediate. The 4.7-Mb SBSA genome was found to encompass a complete soxCDYZAXOB operon, plus one thiosulfate dehydrogenase (tsdA) and sulfite:acceptor oxidoreductase (sorAB) genes. Recombination-based knock-out of tsdA revealed that the entire thiosulfate oxidized by SBSA is first converted to tetrathionate, and no thiosulfate is directly converted to sulfate as typical of the Alphaproteobacterial Sox pathway whereas its tetrathionate-oxidizing ability was as good as that of the wild-type. The ∆soxYZ knock-out mutant exhibited wild-type-like phenotype for thiosulfate/tetrathionate oxidation, whereas ∆soxB oxidized thiosulfate only up to tetrathionate and had complete impairment of tetrathionate oxidation. However, substrate-dependent O2-consumption rate of whole cells, and sulfur-oxidizing enzyme activities of cell-free extracts, measured in the presence/absence of thiol-inhibitors/glutathione, indicated that glutathione plays a key role in SBSA tetrathionate oxidation. All the present findings collectively indicated that glutathione:tetrathionate coupling in Pusillimonas ginsengisoli may involve some unknown proteins other than thiol dehydrotransferase(ThdT), while subsequent oxidation of the potential glutathione:sulfodisulfane and sulfite molecules produced may proceed via soxBCD action.

scholarly journals Molecular mechanism of sulfur chemolithotrophy in the betaproteobacterium Pusillimonas ginsengisoli SBSA

Microbiology ◽  
2020 ◽  
Vol 166 (4) ◽  
pp. 386-397 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Moidu Jameela Rameez ◽  
Sumit Chatterjee ◽  
Jagannath Sarkar ◽  
Prosenjit Pyne ◽  
...  
Keyword(s):  
Type Species ◽  
Sulfur Oxidation ◽  
Content Type ◽  
Whole Cells ◽  
Link Type ◽  
Dual Functional ◽  
Knockout Mutants ◽  
Sulfur Oxidizing ◽  
Sulfur Intermediates ◽  
Tetrathionate Oxidation

Chemolithotrophic sulfur oxidation represents a significant part of the biogeochemical cycling of this element. Due to its long evolutionary history, this ancient metabolism is well known for its extensive mechanistic and phylogenetic diversification across a diverse taxonomic spectrum. Here we carried out whole-genome sequencing and analysis of a new betaproteobacterial isolate, Pusillimonas ginsengisoli SBSA, which is found to oxidize thiosulfate via the formation of tetrathionate as an intermediate. The 4.7 Mb SBSA genome was found to encompass a soxCDYZAXOB operon, plus single thiosulfate dehydrogenase (tsdA) and sulfite : acceptor oxidoreductase (sorAB) genes. Recombination-based knockout of tsdA revealed that the entire thiosulfate is first converted to tetrathionate by the activity of thiosulfate dehydrogenase (TsdA) and the Sox pathway is not functional in this bacterium despite the presence of all necessary sox genes. The ∆soxYZ and ∆soxXA knockout mutants exhibited a wild-type-like phenotype for thiosulfate/tetrathionate oxidation, whereas ∆soxB, ∆soxCD and soxO::KanR mutants only oxidized thiosulfate up to tetrathionate intermediate and had complete impairment in tetrathionate oxidation. The substrate-dependent O2 consumption rate of whole cells and the sulfur-oxidizing enzyme activities of cell-free extracts, measured in the presence/absence of thiol inhibitors/glutathione, indicated that glutathione plays a key role in SBSA tetrathionate oxidation. The present findings collectively indicate that the potential glutathione : tetrathionate coupling in P. ginsengisoli involves a novel enzymatic component, which is different from the dual-functional thiol dehydrotransferase (ThdT), while subsequent oxidation of the sulfur intermediates produced (e.g. glutathione : sulfodisulfane molecules) may proceed via the iterative action of soxBCD .

scholarly journals Water-Soluble Ions in Atmospheric Aerosol Measured in a Semi-Arid and Chemical-Industrialized City, Northwest China

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 456
Author(s):  
Huimin Jiang ◽  
Zhongqin Li ◽  
Feiteng Wang ◽  
Xi Zhou ◽  
Fanglong Wang ◽  
...  
Keyword(s):  
Sulfur Oxidation ◽  
Northwest China ◽  
Water Soluble ◽  
Heterogeneous Reactions ◽  
Anthropogenic Source ◽  
Heating Period ◽  
Qinghai Province ◽  
Soluble Ions ◽  
Water Soluble Ions ◽  
Semi Arid

We investigated water-soluble ions (WSIs) of aerosol samples collected from 2016 to 2017 in Lanzhou, a typical semi-arid and chemical-industrialized city in Northwest China. WSIs concentration was higher in the heating period (35.68 ± 19.17 μg/m3) and lower in the non-heating period (12.45 ± 4.21 μg/m3). NO3−, SO42−, NH4+ and Ca2+ were dominant WSIs. The concentration of SO42− has decreased in recent years, while the NO3− level was increasing. WSIs concentration was affected by meteorological factors. The sulfur oxidation and nitrogen oxidation ratios (SOR and NOR) exceeded 0.1, inferring the vital contribution of secondary transformation. Meanwhile higher O3 concentration and temperature promoted the homogeneous reaction of SO2. Lower temperature and high relative humidity (RH) were more suitable for heterogeneous reactions of NO2. Three-phase cluster analysis illustrated that the anthropogenic source ions and natural source ions were dominant WSIs during the heating and non-heating periods, respectively. The backward trajectory analysis and the potential source contribution function model indicated that Lanzhou was strongly influenced by the Hexi Corridor, northeastern Qinghai–Tibetan Plateau, northern Qinghai province, Inner Mongolia Plateau and its surrounding cities. This research will improve our understanding of the air quality and pollutant sources in the industrial environment.

Eight-membered ring petal-shaped V8 cluster: An efficient heterogeneous catalyst for selective sulfur oxidation

2021 ◽  
Vol 517 ◽  
pp. 120198
Author(s):  
Qing-Dong Ping ◽  
Jia-Peng Cao ◽  
Ye-Min Han ◽  
Mu-Xiu Yang ◽  
Ya-Lin Hong ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Sulfur Oxidation ◽  
Membered Ring ◽  
Efficient Heterogeneous Catalyst

Transcriptional response of Thialkalivibrio versutus D301 to different sulfur sources and identification of the sulfur oxidation pathways

2021 ◽  
Vol 329 ◽  
pp. 160-169
Author(s):  
Zhi-Xia Liu ◽  
Mao-Hua Yang ◽  
Ting-Zhen Mu ◽  
Jin-Long Liu ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Transcriptional Response ◽  
Sulfur Oxidation
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