نتایج جستجو برای: sulphide ore
تعداد نتایج: 12871 فیلتر نتایج به سال:
The utilization of several inorganic and organic sulphur compounds by three strains of Clostridium perfringens and the production of hydrogen sulphide from these compounds was investigated. Sulphate, sulphite, thiosulphate and sulphide cannot supply sulphur to the organism, neither do they have any effect, when added in non-toxic concentrations, on the growth in media containing utilizable orga...
In the magmatic-hydrothermal environment, fluids with similar metal concentrations and sources may yield contrasting mineral assemblages in successive stages of sulphide mineralization. These differences are linked to physico-chemical conditions mineralizing (e.g., T, pH, fS2, fO2) acquired during their interaction country rocks and/or by mixing groundwater. Here, we integrate petrography osmiu...
In previous and in work to be published, it has been shown that iron sulphide material, produced by sulphate-reducing bacteria (SRB), is an excellent adsorbent for a wide range of heavy metals. The material adsorbs between 100 and 400 mg g~1 and residual levels in solutions can be of the order of pg per litre. Further, strongly magnetic forms of this material can now be produced which can be e!...
Symbiotic associations between marine invertebrates and sulphur-oxidising bacteria are a common feature in communities from sulphide-rich environments, such as those flourishing in the vicinity of hydrothermal vents. While the bacterial endosymbionts provide the host with an undoubted nutritional advantage, their presence also requires specific adaptations for the transport and storage of sulph...
IN the ordinary putrefaction of protein material the protein-sulphur is liberated mainly as hydrogen sulphide accompanied in a few cases by relatively small amounts of mercaptans. The present paper is an account of an organism which is capable of the aerobic degradation of l-cystine with the direct liberation of free sulphur. In earlier work on the bacterial decomposition of cystine the medium ...
The sulphide-binding protein that occurs in high concentrations in the vascular blood and coelomic fluid of the hydrothermal vent tube-worm Riftia pachyptila Jones is the haemoglobin. Sulphide binding does not occur at the oxygen-binding sites of the haem, but may occur via thiol-disulphide exchange at the interchain disulphide bridges on the macromolecule. We have confirmed the report that vas...
The majority of global petroleum is in the form of highly viscous heavy oil. Traditionally heavy oil in sands at shallow depths is accessed by large scale mining activities. Recently steam has been used to allow heavy oil extraction with greatly reduced surface disturbance. However, in situ thermal recovery processes can generate hydrogen sulphide, high levels of which are toxic to humans and c...
Zoothamnium niveum (Ciliophora, Oligohymenophora) is a giant, colonial marine ciliate from sulphide-rich, shallow-water habitats, obligatorily associated with the ectosymbiotic, chemoautotrophic, sulphide-oxidizing bacterium 'Candidatus Thiobios zoothamnicoli'. The aims of this study were to characterize the natural habitat and investigate growth, reproduction, survival and maintenance of the s...
1. The metabolism of diallyl disulphide was investigated in vitro with rat and human liver cell subfractions and ex vivo with an isolated perfused rat liver. 2. Diallyl disulphide was oxidized to diallylthiosulphinate by rat liver microsomes with an apparent K(m) = 0.86 +/- 0.1 mM and an apparent V(max) = 0.47 +/- 0.12 nmol min(-1) mg(-1) protein (mean +/- SE). Both cytochrome P450 (CYP) and fl...
found around East-Pacific Rise hydrothermal vents is the giant tube-worm Riftia pachyptila Jones, 1981. This “autotrophic” animal is devoid of a digestive system and acquires metabolic energy from the oxidation of sulphide by chemolithoautotrophic bacteria that live symbiotically inside a specific, highly vascularized organ, the trophosome. Therefore, blood transport nutrients is a crucial issu...
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