The objective of this work was to investigate the reaction stoichiometry, kinetics, and mechanism for Cr(VI) reduction by hydrogen sulfide in the aqueous phase. Batch experiments with excess [Cr(VI)] over [H2S]T indicated that the molar amount of sulfide required for the reduction of 1 M Cr(VI) was 1.5, suggesting the following stoichiometry: 2CrO4(2-) + 3H2S + 4H+-->2Cr(OH)3(s) + 3S(s) + 2H2O....

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Hydrogen sulfide (H2S) is a ubiquitous signaling molecule with important functions in many mammalian organs and systems. Observations in the 1990s ascribed physiological actions to H2S in the nervous system, proposing that this gasotransmitter acts as a neuromodulator. Soon after that, the vasodilating properties of H2S were demonstrated. In the past decade, H2S was shown to exert a multitude o...

An inexpensive paper-based sensor was developed for detecting low ppm concentrations of hydrogen sulfide gas. A piece of filter paper containing aquohydroxocobinamide [OH(H2O)Cbi] was placed on the end of a bifurcated optical fiber, and the reflectance spectrum of the OH(H2O)Cbi was monitored during exposure to 10.0 ppm hydrogen sulfide gas (NIOSH recommended exposure limit). Reaction of sulfid...

H(2)S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of gamma-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H(2)S production in the vasculature. However, patients with inherited deficiency in gamma-cystathiona...

which oxidizes H 2 S to persulfide. SQRs were initially identified in invertebrates, and their mammalian counterpart SQRs were later discovered (Theissen et al., 2003; Theissen and Martin, 2008). In the presence of O 2 and water, sulfur dioxygenase oxidizes persulfide to sulfite, which is combined with another persulfide molecule by sulfur transferase rhodanese in order to producing thiosulfate...

Desulfovitio d&dfUTiCam is an obligately anaerobic organism that can bc grown heterotrophically with sulfate and an organic electron donor or autotrophically with sulfate, hydrogen, and CO* (1). The presence of sulfate is obligatory for growth both with hydrogen and organic electron donors, except in the case of pyruvate (2). During growth, large amounts of sulfide are produced from the sulfate...