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Ambio Feb 2022Dimethyl sulphide (DMS) and carbon monoxide (CO) are climate-relevant trace gases that play key roles in the radiative budget of the Arctic atmosphere. Under global... (Review)
Review
Dimethyl sulphide (DMS) and carbon monoxide (CO) are climate-relevant trace gases that play key roles in the radiative budget of the Arctic atmosphere. Under global warming, Arctic sea ice retreats at an unprecedented rate, altering light penetration and biological communities, and potentially affect DMS and CO cycling in the Arctic Ocean. This could have socio-economic implications in and beyond the Arctic region. However, little is known about CO production pathways and emissions in this region and the future development of DMS and CO cycling. Here we summarize the current understanding and assess potential future changes of DMS and CO cycling in relation to changes in sea ice coverage, light penetration, bacterial and microalgal communities, pH and physical properties. We suggest that production of DMS and CO might increase with ice melting, increasing light availability and shifting phytoplankton community. Among others, policy measures should facilitate large-scale process studies, coordinated long term observations and modelling efforts to improve our current understanding of the cycling and emissions of DMS and CO in the Arctic Ocean and of global consequences.
Topics: Arctic Regions; Carbon Monoxide; Climate; Ice Cover; Oceans and Seas; Sulfides
PubMed: 34480730
DOI: 10.1007/s13280-021-01612-z -
Journal of Environmental Management Sep 2022The depletion of primary ores, the environmental concerns related to mining activities, and the need to promote circular economy has drawn attention to the recycling of...
The depletion of primary ores, the environmental concerns related to mining activities, and the need to promote circular economy has drawn attention to the recycling of metallic compounds. Bio-based technologies are suitable for metal recovery, as they operate under mild conditions (ambient temperature and pressure) and are ideal for treating low-concentration waters. This study compared the effectiveness of adsorption and precipitation for the removal and recovery of gallium, germanium and zinc. Adsorption of the metallic ions on elemental forms of sulfur (S), selenium (Se) and tellurium (Te), both of chemical and biological sources, was tested. Biosorption onto elemental forms of S, Se and Te effectively removed Ga and Zn. The highest removal efficiency (ղ) was obtained for Ga onto the adsorbent Te (69 ± 0.4%), with an adsorption capacity (q) of 74 mg Ga (g Te), followed by Zn (ղ = 40 ± 0.7%) with 43 mg Zn (g Te). Precipitation with chemical and biogenic sulfide at different metal to sulfide (Me/S) ratios was also assessed. Biologically produced sulfide was more efficient for Ga and Zn compared to chemical sulfide. Precipitation with biogenic sulfide was efficient for the removal of Ga (ղ = 59.9 ± 2.6%) and Zn (ղ = 44.2 ± 3.0%). The lowest ratio between metal to sulfide (Me/S = 0.2) achieved higher zinc removal efficiencies, whereas gallium removal was more efficient at Me/S = 1.5. None of the tested methods allowed for recovery of Ge. Biosorption and bioprecipitation gave nevertheless high removal and recovery of Ga and Zn.
Topics: Adsorption; Biomineralization; Gallium; Germanium; Hydrogen-Ion Concentration; Sulfides; Water Pollutants, Chemical; Zinc
PubMed: 35751242
DOI: 10.1016/j.jenvman.2022.115396 -
Chemosphere May 2023Total Dissolved Sulfide (TDS) concentrations can either be derived from simultaneous measurement of pH and one of the sulfide species or determined indirectly in samples...
Total Dissolved Sulfide (TDS) concentrations can either be derived from simultaneous measurement of pH and one of the sulfide species or determined indirectly in samples following an acidification step. Here we report a microsensor that allows for direct measurement of TDS in aquatic media without the need for pH monitoring. An acidic chamber placed in front of a commercial, amperometric HS microsensor allows for the in-situ conversion of dissolved ionic sulfide species to HS, which in turn is oxidized at the transducer anode. A typical sensor had a tip opening of 30 μm, a response time of <50 s and linear range between 0.5 and 650 μM. The sensor performance can be largely tuned by altering the geometry of the chamber. Sensors of different sensitivity (0.04-2.93 pA/μM) showed no noticeable change in zero current and sensitivity during continuous polarization over 7 weeks. The sensor was successfully applied to resolve microscale TDS gradients in freshwater and marine sediments. Other avenues of application include the online monitoring of industrial and urban sewers.
Topics: Hydrogen Sulfide; Electrodes; Sulfides
PubMed: 36841451
DOI: 10.1016/j.chemosphere.2023.138229 -
The Science of the Total Environment Oct 2023Hydrogen sulphide (HS) removal from biogas is of high relevance as it damages combustion engines used for heat and power generation and causes adverse public health and... (Review)
Review
Hydrogen sulphide (HS) removal from biogas is of high relevance as it damages combustion engines used for heat and power generation and causes adverse public health and environmental effects. Biological processes have been reported as a cost-effective and promising approach to desulfurize biogas. This review presents a detailed description of the biochemical foundations of the metabolic apparatus of HS oxidizing bacteria, namely chemolithoautotrophs and anoxygenic photoautotrophs. The review focuses on the current and future applications of biological processes for biogas desulfurization and provides insights into their mechanism and main factors influencing their performance. The advantages, drawbacks, limitations, and technical improvements of the biotechnological applications currently based on chemolithoautotrophic organisms are covered extensively. Recent advances, sustainability and economical aspects of biological biogas desulfurization are also discussed. Anoxygenic photoautotrophic-bacteria-based photobioreactors were herein identified as useful tools to improve the sustainability and safety of biological biogas desulfurization. The review addresses gaps in the existing studies concerning the selection of the most suitable desulfurization techniques, their benefits and consequences. The research is useful for all stakeholders involved in the management and optimization of biogas and its findings are directly applicable in the development of new sustainable technologies for biogas upgrading processes on waste treatment plants.
Topics: Biofuels; Bioreactors; Sulfides; Hydrogen Sulfide; Biotechnology; Photobioreactors
PubMed: 37315597
DOI: 10.1016/j.scitotenv.2023.164689 -
Water Research Dec 2022For over 30 years, biological gas desulfurization under halo-alkaline conditions has been studied and optimized. This technology is currently applied in already 270...
For over 30 years, biological gas desulfurization under halo-alkaline conditions has been studied and optimized. This technology is currently applied in already 270 commercial installations worldwide. Sulfur particle separation, however, remains a challenge; a fraction of sulfur particles is often too small for liquid-solid separation with conventional separation technology. In this article, we report the effects of a novel sulfidic reactor, inserted in the conventional process set-up, on sulfur particle size and morphology. In the sulfidic reactor polysulfide is produced by the reaction of elemental sulfur particles and sulfide, which is again converted to elemental sulfur in a gas-lift reactor. We analyzed sulfur particles produced in continuous, long term lab-scale reactor experiments under various sulfide concentrations and sulfidic retention times. The analyses were performed with laser diffraction particle size analysis and light microscopy. These show that the smallest particles (< 1 µm) have mostly disappeared under the highest sulfide concentration (4.1 mM) and sulfidic retention time (45 min). Under these conditions also agglomeration of sulfur particles was promoted. Model calculations with thermodynamic and previously derived kinetic data on polysulfide formation confirm the experimental data on the removal of the smallest particles. Under the 'highest sulfidic pressure', the model predicts that equilibrium conditions are reached between sulfur, sulfide and polysulfide and that 100% of the sulfur particles <1 µm are dissolved by the (autocatalytic) formation of polysulfides. These experiments and modeling results demonstrate that the insertion of a novel sulfidic reactor in the conventional process set-up promotes the removal of the smallest individual sulfur particles and promotes the production of sulfur agglomerates. The novel sulfidic reactor is therefore a promising process addition with the potential to improve process operation, sulfur separation and sulfur recovery.
Topics: Sulfides; Sulfur; Oxidation-Reduction; Kinetics; Bioreactors
PubMed: 36351351
DOI: 10.1016/j.watres.2022.119296 -
Environmental Toxicology and Chemistry Jun 2019It is well established that sulfide can be toxic to rooted aquatic plants. However, a detailed description of the effects of cumulative sulfate loads on sulfide and iron...
It is well established that sulfide can be toxic to rooted aquatic plants. However, a detailed description of the effects of cumulative sulfate loads on sulfide and iron (Fe) porewater geochemistry, plant exposure, and ecological response is lacking. Over 4 yr, we experimentally manipulated sulfate loads to self-perpetuating wild rice (Zizania palustris) populations and monitored increases in the ratio of sulfur (S) to Fe in sediment across a range of sulfide loading rates driven by overlying water sulfate. Because natural settings are complicated by ongoing Fe and S loads from surface and groundwater, this experimental setting provides a tractable system to describe the impacts of increased S loading on Fe-S porewater geochemistry. In the experimental mesocosms, the rate of sulfide accumulation in bulk sediment increased linearly with overlying water sulfate concentration up to 300 µg-SO cm . Seedling survival at the beginning of the annual life cycle and seed mass and maturation at the end of the annual life cycle all decreased at porewater sulfide concentrations between 0.4 and 0.7 µg cm . Changes to porewater sulfide, plant emergence, and plant nutrient uptake during seed production were closely related to the ratio of S to Fe in sediment. A mass balance analysis showed that porewater sulfide remained a small and relatively transient phase compared to sulfate in the overlying water and Fe in the sediment solid phase. The results illuminate the evolution of the geochemical setting and timescales over which 4 yr of cumulative sulfate loading resulted in a wholesale shift from Fe-dominated to sulfide-dominated porewater chemistry. This shift was accompanied by detrimental effects to, and eventual extirpation of, self-perpetuating wild rice populations. Environ Toxicol Chem 2019;38:1231-1244. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Topics: Fresh Water; Geologic Sediments; Iron; Plant Development; Poaceae; Porosity; Reproduction; Sulfates; Sulfides; Water; Water Pollutants, Chemical; Wetlands
PubMed: 30901093
DOI: 10.1002/etc.4410 -
Biochimica Et Biophysica Acta Jul 2009Hydrogen sulfide (H(2)S) has been known for hundreds of years because of its poisoning effect. Once the basal bio-production became evident its pathophysiological role... (Review)
Review
Hydrogen sulfide (H(2)S) has been known for hundreds of years because of its poisoning effect. Once the basal bio-production became evident its pathophysiological role started to be investigated in depth. H(2)S is a gas that can be formed by the action of two enzymes, cystathionine gamma-lyase and cystathionine beta-synthase, both involved in the metabolism of cysteine. It has several features in common with the other two well known "gasotransmitters" (nitric oxide and carbon monoxide) in the biological systems. These three gasses share some biological targets; however, they also have dissimilarities. For instance, the three gases target heme-proteins and open K(ATP) channels; H(2)S as NO is an antioxidant, but in contrast to the latter molecule, H(2)S does not directly form radicals. In the last years H(2)S has been implicated in several physiological and pathophysiological processes such as long term synaptic potentiation, vasorelaxation, pro- and anti-inflammatory conditions, cardiac inotropism regulation, cardioprotection, and several other physiological mechanisms. We will focus on the biological role of H(2)S as a molecule able to trigger cell signaling. Our attention will be particularly devoted on the effects in cardiovascular system and in cardioprotection. We will also provide available information on H(2)S-donating drugs which have so far been tested in order to conjugate the beneficial effect of H(2)S with other pharmaceutical properties.
Topics: Animals; Cardiovascular System; Cystathionine beta-Synthase; Cystathionine gamma-Lyase; Gases; Humans; Hydrogen Sulfide; Models, Biological; Nitric Oxide; Signal Transduction; Sulfides
PubMed: 19285949
DOI: 10.1016/j.bbabio.2009.03.005 -
Applied and Environmental Microbiology Feb 2022Sulfur-oxidizing bacteria can oxidize hydrogen sulfide (HS) to produce sulfur globules. Although the process is common, the pathway is unclear. In recombinant...
Sulfur-oxidizing bacteria can oxidize hydrogen sulfide (HS) to produce sulfur globules. Although the process is common, the pathway is unclear. In recombinant Escherichia coli and wild-type Corynebacterium vitaeruminis DSM 20294 with sulfide:quinone oxidoreductase (SQR) but no enzymes to oxidize zero valence sulfur, SQR oxidized HS into short-chain inorganic polysulfide (HS, ≥ 2) and organic polysulfide (RSH, ≥ 2), which reacted with each other to form long-chain GSH ( ≥ 2) and HS before producing octasulfur (S), the main component of elemental sulfur. GSH also reacted with glutathione (GSH) to form GSG ( ≥ 2) and HS; HS was again oxidized by SQR. After GSH was depleted, SQR simply oxidized HS to HS, which spontaneously generated S. S aggregated into sulfur globules in the cytoplasm. The results highlight the process of sulfide oxidation to S globules in the bacterial cytoplasm and demonstrate the potential of using heterotrophic bacteria with SQR to convert toxic HS into relatively benign S globules. Our results provide evidence of HS oxidation producing octasulfur globules via sulfide:quinone oxidoreductase (SQR) catalysis and spontaneous reactions in the bacterial cytoplasm. Since the process is an important event in geochemical cycling, a better understanding facilitates further studies and provides theoretical support for using heterotrophic bacteria with SQR to oxidize toxic HS into sulfur globules for recovery.
Topics: Bacteria, Aerobic; Cytoplasm; Hydrogen Sulfide; Oxidation-Reduction; Quinone Reductases; Sulfides
PubMed: 34878813
DOI: 10.1128/AEM.01941-21 -
Current Drug Metabolism 2015Diallyl sulfide (DAS) and other organosulfur compounds are chief constituents of garlic. These compounds have many health benefits, as they are very efficient in... (Review)
Review
Diallyl sulfide (DAS) and other organosulfur compounds are chief constituents of garlic. These compounds have many health benefits, as they are very efficient in detoxifying natural agents. Therefore, these compounds may be useful for prevention/treatment of cancers. However, DAS has shown appreciable allergic reactions and toxicity, as they can also affect normal cells. Thus their use as in the prevention and treatment of cancer is limited. DAS is a selective inhibitor of cytochrome P450 2E1 (CYP2E1), which is known to metabolize many xenobiotics including alcohol and analgesic drugs in the liver. CYP2E1-mediated alcohol/drug metabolism produce reactive oxygen species and reactive metabolites, which damage DNA, protein, and lipid membranes, subsequently causing liver damage. Several groups have shown that DAS is not only capable of inhibiting alcohol- and drug-mediated cellular toxicities, but also HIV protein- and diabetes-mediated toxicities by selectively inhibiting CYP2E1 in various cell types. However, due to known DAS toxicities, its use as a treatment modality for alcohol/drug- and HIV/diabetes-mediated toxicity have only limited clinical relevance. Therefore, effort is being made to generate DAS analogs, which are potent and selective inhibitor of CYP2E1 and poor substrate of CYP2E1. This review summarizes current advances in the field of DAS, its anticancer properties, role as a CYP2E1 inhibitor, preventing agent of cellular toxicities from alcohol, analgesic drugs, xenobiotics, as well as, from diseases like HIV and diabetes. Finally, this review also provides insights toward developing novel DAS analogues for chemical intervention of many disease conditions by targeting CYP2E1 enzyme.
Topics: Allyl Compounds; Analgesics; Animals; Antineoplastic Agents; Cytochrome P-450 CYP2E1; Cytoprotection; Ethanol; Humans; Protective Agents; Sulfides; Xenobiotics
PubMed: 26264202
DOI: 10.2174/1389200216666150812123554 -
Journal of Bacteriology Sep 2021Methanogens have a high demand for iron (Fe) and sulfur (S); however, little is known of how they acquire, deploy, and store these elements and how this, in turn,...
Methanogens have a high demand for iron (Fe) and sulfur (S); however, little is known of how they acquire, deploy, and store these elements and how this, in turn, affects their physiology. Methanogens were recently shown to reduce pyrite (FeS), generating aqueous iron sulfide (FeS) clusters that are likely assimilated as a source of Fe and S. Here, we compared the phenotypes of Methanococcus voltae grown with FeS or ferrous iron [Fe(II)] and sulfide (HS). FeS-grown cells are 33% smaller yet have 193% more Fe than Fe(II)/HS-grown cells. Whole-cell electron paramagnetic resonance revealed similar distributions of paramagnetic Fe, although FeS-grown cells showed a broad spectral feature attributed to intracellular thioferrate-like nanoparticles. Differential proteomic analyses showed similar expression of core methanogenesis enzymes, indicating that Fe and S source does not substantively alter the energy metabolism of cells. However, a homolog of the Fe(II) transporter FeoB and its putative transcriptional regulator DtxR were up-expressed in FeS-grown cells, suggesting that cells sense Fe(II) limitation. Two homologs of IssA, a protein putatively involved in coordinating thioferrate nanoparticles, were also up-expressed in FeS-grown cells. We interpret these data to indicate that, in FeS-grown cells, DtxR cannot sense Fe(II) and therefore cannot downregulate FeoB. We suggest this is due to the transport of Fe(II) complexed with sulfide (FeS), leading to excess Fe that is sequestered by IssA as a thioferrate-like species. This model provides a framework for the design of targeted experiments aimed at further characterizing Fe acquisition and homeostasis in M. voltae and other methanogens. FeS is the most abundant sulfide mineral in the Earth's crust and is common in environments inhabited by methanogenic archaea. FeS can be reduced by methanogens, yielding aqueous FeS clusters that are thought to be a source of Fe and S. Here, we show that growth of Methanococcus voltae on FeS results in smaller cell size and higher Fe content per cell, with Fe likely stored intracellularly as thioferrate-like nanoparticles. Fe(II) transporters and storage proteins were upregulated in FeS-grown cells. These responses are interpreted to result from cells incorrectly sensing Fe(II) limitation due to assimilation of Fe(II) as FeS. These findings have implications for our understanding of how Fe/S availability influences methanogen physiology and the biogeochemical cycling of these elements.
Topics: Bacterial Proteins; Biological Transport; Carrier Proteins; Electron Spin Resonance Spectroscopy; Gene Expression Regulation, Bacterial; Iron; Metal Nanoparticles; Methanococcus; Sulfides
PubMed: 34251867
DOI: 10.1128/JB.00146-21