The Sulphur Cycle: Definitions, Mechanisms and Dynamics

Kelly, Donovan P.

doi:10.1002/9780470720554.ch2

Cited by 8 publications

(4 citation statements)

References 31 publications

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“…In the anaerobic atmosphere of early geological times, the biological cycle of S is thought to have been initiated by microorganisms transforming inorganic SO 4 2− groups into gaseous H 2 S, a reduced S product manifesting high instability and reacting capacity . This reducing process is a form of primitive respiration requiring considerable energy from bacteria and fungi and the intervention of cytochromes and flavoproteins in support of electron exchanges . The growth of oxidizing as well as reducing microorganisms, the accumulation of H 2 S in the biosphere, and the later occurrence of photosynthesis in microscopic plants has created reciprocal exchanges between anaerobic and aerobic ecosystems at the origin of primitive life on earth .…”

Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

“…11,12 The growth of oxidizing as well as reducing microorganisms, the accumulation of H2S in the biosphere, and the later occurrence of photosynthesis in microscopic plants has created reciprocal exchanges between anaerobic and aerobic ecosystems at the origin of primitive life on earth. 12 It is worth recalling that S is situated directly below oxygen (O) in the periodic table of elements, which indicates that bacteria living in anaerobiosis breathe S in the same sense that aerobic organisms breathe oxygen. 9 Remnants of these primitive ecosystems still remain, confined largely to inhospitable places such as volcanic areas, swamps, and ocean beds.…”

Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

“…This reducing process is a form of primitive respiration requiring considerable energy from bacteria and fungi and the intervention of cytochromes and flavoproteins in support of electron exchanges . The growth of oxidizing as well as reducing microorganisms, the accumulation of H 2 S in the biosphere, and the later occurrence of photosynthesis in microscopic plants has created reciprocal exchanges between anaerobic and aerobic ecosystems at the origin of primitive life on earth . It is worth recalling that S is situated directly below oxygen (O) in the periodic table of elements, which indicates that bacteria living in anaerobiosis breathe S in the same sense that aerobic organisms breathe oxygen .…”

Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

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Nutritional essentiality of sulfur in health and disease

Ingenbleek¹,

Kimura

2013

Nutr Rev

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Sulfur is the seventh most abundant element measurable in the human body and is supplied mainly by the intake of methionine (Met), an indispensable amino acid found in plant and animal proteins. Met controls the initiation of protein synthesis, governs major metabolic and catalytic activities, and may undergo reversible redox processes safeguarding protein integrity. Withdrawal of Met from customary diets causes the greatest downsizing of lean body mass following either unachieved replenishment (malnutrition) or excessive losses (inflammation). These physiopathologically unrelated morbidities nevertheless stimulate comparable remethylation reactions from homocysteine, indicating that Met homeostasis benefits from high metabolic priority. Inhibition of cystathionine-β-synthase activity causes the upstream sequestration of homocysteine and the downstream drop in cysteine and glutathione. Consequently, the enzymatic production of hydrogen sulfide and the nonenzymatic reduction of elemental sulfur to hydrogen sulfide are impaired. Sulfur operates as cofactor of several enzymes critically involved in the regulation of oxidative processes. A combination of malnutrition and nutritional deprivation of sulfur maximizes the risk of cardiovascular disorders and stroke, constituting a novel clinical entity that threatens plant-eating population groups.

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Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

Section: Physicochemical Characteristics Of Sulfurmentioning

confidence: 99%

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Nutritional essentiality of sulfur in health and disease

Ingenbleek¹,

Kimura

2013

Nutr Rev

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“…The biological cycle of S is thought to have been initiated by microorganisms transforming inorganic sulfate groups into gazeous hydrogen sulfide, a form of primitive respiration at the origin of anaerobic life on earth [1]. The later occurrence of photosynthesis in microscopic plants has created reciprocal exchanges between anaerobic and aerobic ecosystems [2]. The progressive enrichment in oxygen of the atmosphere has favored the emergence of higher plants and aerobic animals [3].…”

Section: Introductionmentioning

confidence: 99%

Hyperhomocysteinemia is a Biomarker of Sulfur-Deficiency in Human Morbidities~!2009-10-03~!2009-11-18~!2009-12-22~!

Ingenbleek¹

2010

TOCCHEMJ

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Methionine (Met) is crucially involved in the synthesis of S-compounds endowed with molecular, structural and functional properties of survival value. Dietary Met may undergo transmethylation processes to release homocysteine (Hcy) which may either be regenerated to Met following remethylation (RM) pathways or catabolized along the transsulfuration (TS) cascade. The activity of enzymes governing RM and TS pathways is depending on pyridoxine, folate and cobalamin bioavailability. Dietary restriction in any of these watersoluble B-vitamins may lead to hyperhomocysteinemia (HHcy) causing a panoply of cardiovascular disorders. Taken together, the vitamin triad only affords partial account of Hcy variance, prompting the search for additional causal factor(s). Body composition studies demonstrate that nitrogen (N) and sulfur (S) maintain tightly correlated concentrations in tissues of both healthy subjects and diseased patients. Any morbid condition characterized by insufficient N intake or assimilation, as seen in protein malnutrition or intestinal malabsorption, reduces body S accretion rates. Excessive urinary N-losses, as reported in acute or chronic inflammatory disorders, entail proportionate obligatory S-losses. As a result, lean body mass (LBM) undergoes downsizing and concomitant depletion of N and S body stores which depresses the activity of cystathionine--synthase, thereby promoting upstream accumulation of Hcy and overstimulation of RM processes. HHcy thus appears as the dark side of efforts developed by S-deprived patients to safeguard Met homeostasis. Irrespective of vitamin-B status, Hcy values are negatively correlated with LBM shrinkage well identified by the serial measurement of plasma transthyretin (TTR). The Sdeprivation theory fulfills the gap and allows full causal coverage of the metabolic anomaly, hence providing together with vitamin-deficiencies an unifying overview of the main nutritional determinants implicated in HHcy epidemiology.

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The Reduction of Sulfate and the Oxidation of Sulfide

Huxtable

1986

Biochemistry of Sulfur

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The Sulphur Cycle: Definitions, Mechanisms and Dynamics

Cited by 8 publications

References 31 publications

Nutritional essentiality of sulfur in health and disease

Nutritional essentiality of sulfur in health and disease

Hyperhomocysteinemia is a Biomarker of Sulfur-Deficiency in Human Morbidities~!2009-10-03~!2009-11-18~!2009-12-22~!

The Reduction of Sulfate and the Oxidation of Sulfide

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