Elucidation of the nitrogen-transformation mechanism for nitrite removal using a microbial-mediated iron redox cycling system

Abstract Abstract Nitrogen migration and transformation in the stormwater bioretention system were studied in laboratory experiments, in which the effects of drying-rewetting were particularly investigated. The occurrence and distribution of nitrogen in the plants, the soil, and the pore water were explored under different drying-rewetting cycles. The results clearly showed that bioretention system could remove nitrogen efficiently in all drying-rewetting cycles. The incoming nitrogen could be retained in the topsoil (0–10 cm) and accumulated in the planted layer. However, the overlong dry periods (12 and 22 days) cause an increase in nitrate in the pore water. In addition, nitrogen is mostly stored in the plants’ stem tissues. Up to 23.26% of the inflowing nitrogen can be immobilized in plant organ after a dry period of 22 days. In addition, the relationships between nitrogen reductase activity in the soil and soil nitrogen content were explored. The increase of soil TN content could enhance the activity of nitrate reductase. Meanwhile, the activity of hydroxylamine reductase (HyR) could be enhanced with the increase of soil NO3− content. These results provide a reference for the future development of nitrogen transformation mechanism and the construction of stormwater bioretention systems.

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Fungus-initiated catalytic reactions at hyphal-mineral interfaces drive iron redox cycling and biomineralization

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2019.06.029 ◽

2019 ◽

Vol 260 ◽

pp. 192-203 ◽

Cited By ~ 10

Author(s):

Guang-Hui Yu ◽

Zhi-Lai Chi ◽

H. Henry Teng ◽

Hai-Liang Dong ◽

Andreas Kappler ◽

...

Keyword(s):

Redox Cycling ◽

Catalytic Reactions ◽

Mineral Interfaces ◽

Iron Redox

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In Vivo Two-Way Redox Cycling System for Independent Duplexed Electrochemical Signal Amplification

Analytical Chemistry ◽

10.1021/acs.analchem.9b00053 ◽

2019 ◽

Vol 91 (8) ◽

pp. 4939-4942 ◽

Cited By ~ 6

Author(s):

Yuan Yang ◽

Yang-Yang Yu ◽

Yu-Tong Shi ◽

Jamile Mohammadi Moradian ◽

Yang-Chun Yong

Keyword(s):

Signal Amplification ◽

Redox Cycling ◽

Electrochemical Signal ◽

Cycling System

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Impact of ecohydrological fluctuations on iron-redox cycling

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2019.03.013 ◽

2019 ◽

Vol 133 ◽

pp. 188-195 ◽

Cited By ~ 1

Author(s):

Salvatore Calabrese ◽

Amilcare Porporato

Keyword(s):

Redox Cycling ◽

Iron Redox

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Induction of Gamma-Glutamyltransferase Activity and Consequent Pro-oxidant Reactions in Human Macrophages Exposed to Crocidolite Asbestos

Toxicological Sciences ◽

10.1093/toxsci/kfz175 ◽

2019 ◽

Vol 177 (2) ◽

pp. 476-482 ◽

Cited By ~ 1

Author(s):

Alessandro Corti ◽

Justine Bonetti ◽

Silvia Dominici ◽

Simona Piaggi ◽

Vanna Fierabracci ◽

...

Keyword(s):

Oxidative Stress ◽

Hydroxyl Radical ◽

Fenton Reaction ◽

Redox Cycling ◽

Pathogenic Potential ◽

Gamma Glutamyltransferase ◽

Reduction Of Iron ◽

Healthy Donors ◽

Iron Redox

Abstract Asbestos is the main causative agent of malignant pleural mesothelioma. The variety known as crocidolite (blue asbestos) owns the highest pathogenic potential, due to the dimensions of its fibers as well as to its content of iron. The latter can in fact react with macrophage-derived hydrogen peroxide in the so called Fenton reaction, giving rise to highly reactive and mutagenic hydroxyl radical. On the other hand, hydroxyl radical can as well originate after thiol-dependent reduction of iron, a process capable of starting its redox cycling. Previous studies showed that glutathione (GSH) is one such thiol, and that cellular gamma-glutamyltransferase (GGT) can efficiently potentiate GSH-dependent iron redox cycling and consequent oxidative stress. As GGT is expressed in macrophages and is released upon their activation, the present study was aimed at verifying the hypothesis that GSH/GGT-dependent redox reactions may participate in the oxidative stress following the activation of macrophages induced by crocidolite asbestos. Experiments in acellular systems confirmed that GGT-mediated metabolism of GSH can potentiate crocidolite-dependent production of superoxide anion, through the production of highly reactive dipeptide thiol cysteinyl-glycine. Cultured THP-1 macrophagic cells, as well as isolated monocytes obtained from healthy donors and differentiated to macrophages in vitro, were investigated as to their expression of GGT and the effects of exposure to crocidolite. The results show that crocidolite asbestos at subtoxic concentrations (50–250 ng/1000 cells) can upregulate GGT expression, which raises the possibility that macrophage-initiated, GSH/GGT-dependent pro-oxidant reactions may participate in the pathogenesis of tissue damage and inflammation consequent to crocidolite intoxication.

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Endogenous Carbon Monoxide Signaling Modulates Mitochondrial Function and Intracellular Glucose Utilization: Impact of the Heme Oxygenase Substrate Hemin

Antioxidants ◽

10.3390/antiox9080652 ◽

2020 ◽

Vol 9 (8) ◽

pp. 652 ◽

Cited By ~ 2

Author(s):

David Stucki ◽

Julia Steinhausen ◽

Philipp Westhoff ◽

Heide Krahl ◽

Dominik Brilhaus ◽

...

Keyword(s):

Carbon Monoxide ◽

Glucose Metabolism ◽

Respiratory Chain ◽

Heme Oxygenase ◽

Antioxidant Defense ◽

Redox Cycling ◽

Short Term ◽

Heme Oxygenases ◽

Cycling System

Stress-inducible heme oxygenase-1 (HO-1) catalyzes the oxidative cleavage of heme yielding biliverdin, ferrous iron, and carbon monoxide (CO). Heme oxygenase activity has been attributed to antioxidant defense via the redox cycling system of biliverdin and bilirubin. There is increasing evidence that CO is a gaseous signaling molecule and plays a role in the regulation of energy metabolism. Inhibitory effects of CO on the respiratory chain are well established, but the implication of such a process on the cellular stress response is not well understood. By means of extracellular flux analyses and isotopic tracing, we studied the effects of CO, either released from the CO donor CORM-401 or endogenously produced by heme oxygenases, on the respiratory chain and glucose metabolism. CORM-401 was thereby used as a tool to mimic endogenous CO production by heme oxygenases. In the long term (>60 min), CORM-401-derived CO exposure inhibited mitochondrial respiration, which was compensated by increased glycolysis accompanied by a loss of the ATP production rate and an increase in proton leakage. This effect pattern was likewise observed after endogenous CO production by heme oxygenases. However, in the present setting, these effects were only observed when sufficient substrate for heme oxygenases (hemin) was provided. Modulation of the HO-1 protein level was less important. The long-term influence of CO on glucose metabolism via glycolysis was preceded by a short-term response (<30 min) of the cells to CO. Stable isotope-labeling experiments and metabolic flux analysis revealed a short-term shift of glucose consumption from glycolysis to the pentose phosphate pathway (PPP) along with an increase in reactive oxygen species (ROS) generation. Overall, we suggest that signaling by endogenous CO stimulates the rapid formation of reduction equivalents (NADPH) via the PPP, and plays an additional role in antioxidant defense, e.g., via feed-forward stimulation of the bilirubin/biliverdin redox cycling system.

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Microbial iron-redox cycling in subsurface environments

Biochemical Society Transactions ◽

10.1042/bst20120202 ◽

2012 ◽

Vol 40 (6) ◽

pp. 1249-1256 ◽

Cited By ~ 62

Author(s):

Eric E. Roden

Keyword(s):

Electron Transfer ◽

Iron Oxidation ◽

Anaerobic Respiration ◽

Redox Cycling ◽

Rapid Expansion ◽

Extracellular Electron Transfer ◽

Experimental Systems ◽

Subsurface Environments ◽

Micro Organisms ◽

Iron Redox

In addition to its central role in mediating electron-transfer reactions within all living cells, iron undergoes extracellular redox transformations linked to microbial energy generation through utilization of Fe(II) as a source of chemical energy or Fe(III) as an electron acceptor for anaerobic respiration. These processes permit microbial populations and communities to engage in cyclic coupled iron oxidation and reduction within redox transition zones in subsurface environments. In the present paper, I review and synthesize a few case studies of iron-redox cycling in subsurface environments, highlighting key biochemical aspects of the extracellular iron-redox metabolisms involved. Of specific interest are the coupling of iron oxidation and reduction in field and experimental systems that model redox gradients and fluctuations in the subsurface, and novel pathways and organisms involved in the redox cycling of insoluble iron-bearing minerals. These findings set the stage for rapid expansion in our knowledge of the range of extracellular electron-transfer mechanisms utilized by subsurface micro-organisms. The observation that closely coupled oxidation and reduction of iron can take place under conditions common to the subsurface motivates this expansion in pursuit of molecular tools for studying iron-redox cycling communities in situ.

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