Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activity or their capacity to initiate a respiratory burst. Actually the products of...

Abstract Microbialites accrete where environmental conditions and microbial metabolisms promote lithification, commonly through carbonate cementation. On Little Ambergris Cay, Turks Caicos Islands, mats occur widely in peritidal environments above ooid sand but do not become lithified or preserved. Sediment cores porewater geochemistry indicated that aerobic respiration sulfide oxidation inhibi...

Sulfide mineral processing often produces large quantities of wastewaters containing acid-generating inorganic sulfur compounds. If released untreated, these wastewaters can cause catastrophic environmental damage. In this study, microbial fuel cells were inoculated with acidophilic microorganisms to investigate whether inorganic sulfur compound oxidation can generate an electrical current. Cyc...

A bacterium able to grow via reductive dechlorination of trichloroacetate was isolated from anaerobic soil enrichments. The isolate, designated strain K1, is a member of the delta proteobacteria and is related to other known sulfur and ferric iron reducers. In anaerobic mineral media supplemented with acetate and trichloroacetate, its doubling time was 6 h. Alternative electron donor and accept...

Hydrogen sulfide is gaining acceptance as an endogenously produced modulator of tissue function. The present paradigm of H(2)S (diprotonated, gaseous form of hydrogen sulfide) as a tissue messenger consists of H(2)S being released from the desulfhydration of l-cysteine at a rate sufficient to maintain whole tissue hydrogen sulfide concentrations of 30 microM to >100 microM, and these tissue con...

Chicken liver mitochondria consumed O2 at an accelerated rate when supplied with low concentrations of hydrogen sulfide. Maximum respiration occurred in 10 microM sulfide, and continued more slowly up to concentrations as high as 60 microM. Sulfide oxidation was coupled to adenosine triphosphate (ATP) synthesis, as shown by firefly luciferase luminescence and by measurement of the mitochondrial...

The Huoluotai Cu (Mo) deposit is a recently discovered porphyry in the northern Great Xing’an Range, NE China. Fluid inclusion (FI) micro-thermometry results and C–H–O–S–Pb isotope compositions of are presented this study. ore-forming process consists sulfide-barren quartz stage (I), + chalcopyrite ± pyrite molybdenite (II), polymetallic sulfide (III), calcite fluorite (IV). mineralization occu...

Vesicomyid clams, vestimentiferans, and some bathymodiolin mussels from hydrothermal vents and cold seeps possess thiotrophic endosymbionts, high levels of hypotaurine and, in tissues with symbionts, thiotaurine. The latter, a product of hypotaurine and sulfide, may store and/or transport sulfide non-toxically, and the ratio to hypotaurine plus thiotaurine (Th/[H+Th]) may reflect an animal's su...

Hydrogen sulfide is an essential gasotransmitter associated with numerous pathologies. We assert that hydrogen sulfide plays an important role in regulating macrophage function in response to subsequent inflammatory stimuli, promoting clearance of leukocyte infiltrate and reducing TNF-α levels in vivo following zymosan-challenge. We describe two distinct methods of measuring leukocyte hydrogen ...