Factors affecting bio-oxidation of sulfide minerals at high concentrations of solids: A review

Salmonella enterica serovar Enteritidis (SE) is a major foodborne pathogen primarily causing human infection through contaminated chicken eggs. To understand how SE survives in chicken egg albumen, we systematically and quantitatively analysed the survival properties of SE in egg albumen and identified factors affecting its survival. Survival assays of SE in egg indicate that egg albumen restricted the growth of SE. A major factor that controlled SE's growth in egg albumen was iron restriction, since egg albumen supplemented with iron allowed SE to grow, and iron acquisition mutants of SE showed decreased survival in egg albumen. In addition, low pH of albumen, high concentrations of bacteria and low incubation temperatures of bacteria with albumen facilitates the survival of SE. Our results suggest that egg albumen uses multiple mechanisms to control SE including iron limitation, surface interaction and possible enzymatic activities.

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Formation and characterization of acid mine drainage in the Madzharovo ore field, Southeastern Bulgaria

Engineering Geology and Hydrogeology ◽

10.52321/igh.35.1.41 ◽

2021 ◽

Vol 35 (1) ◽

pp. 41-50

Author(s):

Svetlana Bratkova

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Negative Impact ◽

Sulfide Minerals ◽

Mining Areas ◽

Acid Mine ◽

Zinc Cadmium ◽

High Concentrations ◽

Cadmium Lead ◽

The Impact

The formation of acid mine drainage (AMD) is a serious environmental problem in areas with mining and processing industries worldwide. Their generation is associated with chemical and biological processes of oxidation of sulfide minerals, mainly pyrite. Sources of AMD can be deposits of sulfide minerals and coal with a high content of pyrite sulfur, mining waste and some tailings. The impact of AMD on surface and groundwater in mining areas continues for decades after the cessation of extraction. An example of the negative impact of generated acid mine drainage on the state of surface waters is in the region of Madzharovo. Years after the cessation of mining, the waters at the discharge points "Momina Skala", "Harman Kaya" and "Pandak Dere" are characterized by low pH values and high concentrations of iron, copper, zinc, cadmium, lead and manganese.

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Factors affecting the viscosity of caseinates in dispersions of high concentrations

Journal of Dairy Research ◽

10.1017/s0022029900018768 ◽

1968 ◽

Vol 35 (1) ◽

pp. 31-47 ◽

Cited By ~ 15

Author(s):

J. F. Hayes ◽

Pamela M. Southby ◽

L. L. Muller

Keyword(s):

Methyl Cellulose ◽

Calcium Content ◽

Gel Formation ◽

High Concentration ◽

Factors Affecting ◽

Physical Effects ◽

High Concentrations ◽

Commercial Applications ◽

Reversible Gel

SummaryThe physical effects of various cations in caseinate dispersions of high concentrations were investigated over a range of temperature and pH.With calcium and strontium the temperature-viscosity relationships of the caseinates were abnormal in that the viscosity decreased rapidly from 30 to about 40 °C and a gel formed at temperatures in the region of 50–60 °C. On cooling, the gel reliquefied. No gel formed with barium, aluminium or magnesium. On cooling, magnesium preparations separated into 2 phases.The supernatant phase from the magnesium caseinate and a corresponding phase prepared by centrifuging the calcium caseinate showed depletion of α-casein and enrichment of κ-casein and β-casein. The supernatant phase from the calcium caseinate showed the reversible gel formation on heating. The magnesium supernatant phase did not. κ-Casein and a mixture of κ- and β-caseins gave reversible gels at similar levels of calcium and pH.For reversible gel formation to occur, calcium caseinate was required to be in fairly high concentration, to have a calcium content of about 1·0% of the protein and to be within the pH limits 5·2–6·0. The temperature at which gelation occurred was affected by the concentration of calcium and protein and by pH.The behaviour of the material was compared with that of methyl cellulose with and without addition of urea.Some potential commercial applications of the findings on viscosity relationships are outlined.

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Factors affecting rhizogenesis in vitro and acclimatisation of three cherry rootstocks

International Journal of Horticultural Science ◽

10.31421/ijhs/6/1/64 ◽

2000 ◽

Vol 6 (1) ◽

Author(s):

M. Al-Sabbagh ◽

A. Abdul-Kader ◽

M. Khoder ◽

A. R. Kalhout

Keyword(s):

Field Conditions ◽

Root Initiation ◽

Liquid Media ◽

Factors Affecting ◽

High Concentrations ◽

Cherry Rootstocks

Factors affecting rhizogenesis in vitro and acclimatisation of three rootstocks of cherry, i.e. Mahaleb, Maxma-14 and Weiroot -10 were investigated. Rooting was easily achieved within 2-4 weeks on MS-based liquid or agar-gelled media containing auxins IBA at conc. 0.49 or 2.45 pM or NAA at conc. of 0.49 pM. On liquid media with 2.45 pM IBA, a maximum rooting efficiency of 95-100% was obtained. However, high concentrations of auxin delayed the time of root initiation for 3-5 days. Rooted plantlets were transplanted into pots with a mixture of 3:1 (v/v) peat:perlite and acclimatised gradually to field conditions with efficiency of 60%.

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Factors Affecting Agrobacterium-mediated Transformation of Common Bean

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.3.300 ◽

1997 ◽

Vol 122 (3) ◽

pp. 300-305 ◽

Cited By ~ 18

Author(s):

Zhanyuan Zhang ◽

Dermot P. Coyne ◽

Amitava Mitra

Keyword(s):

Common Bean ◽

Filter Paper ◽

Blue Staining ◽

Transformation Rate ◽

Gus Gene ◽

Reporter System ◽

Factors Affecting ◽

Host Interactions ◽

Optimized Protocol ◽

High Concentrations

Factors influencing Agrobacterium tumefaciens-mediated transformation of common beans (Phaseolus vulgaris L.) were examined using an intron-containing β-glucuronidase (GUS) gene as a reporter system to develop a repeatable transformation protocol. Tissue culture procedures used were based on direct shoot organogenesis. Two A. tumefaciens strains—A2760 and EHA105—were used, with emphasis on the former due to its overall higher infection rate. Eleven common-bean genotypes were compared for susceptibility to strain A2760 or EHA105. The pinto bean `Othello' was used extensively in testing different transformation conditions. Factors significantly affecting transformation rate were Agrobacterium × host interactions, explant maturity, preculture and cocultivation conditions, and selection schemes, based on transient GUS gene expression. The best transformation conditions were the use of susceptible genotypes and explants derived from mature seeds, preconditioning of explants in a medium containing 20 μmol of benzyladenine (BA) in darkness or on a filter paper, dipping explants in high concentrations of Agrobacterium cell suspension (OD650 = 0.8-1.0) followed by a long-term (6-day) cocultivation period on a semisolid agar medium in the presence of cytokinin or 3-day cocultivation on a moistened filter paper, and the use of lethal levels of selective agents. About 4% of explants, or 14% of regenerated shoots or buds, were putatively transgenic, as indicated by GUS blue staining throughout the entire shoot or bud, after explants were transformed with Agrobacterium strain A2760 using an optimized protocol.

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Physiological Factors Affecting Biennial Bearing in Tree Fruit: The Role of Seeds in Apple

HortTechnology ◽

10.21273/horttech.9.3.317 ◽

1999 ◽

Vol 9 (3) ◽

pp. 317-322 ◽

Cited By ~ 23

Author(s):

Frank G. Dennis ◽

John C. Neilsen

Keyword(s):

Alternative Hypothesis ◽

Apple Fruit ◽

Physiological Factors ◽

Factors Affecting ◽

Biennial Bearing ◽

Relevant Evidence ◽

Tree Fruit ◽

Apple Cultivars ◽

High Concentrations

The evidence for several hypotheses regarding the mechanism(s) controlling biennial bearing in apple (Malus×domestica Borkh.) are reviewed, citing relevant evidence from work with citrus (Citrus sp.) species and pear (Pyrus communis L.). The view that flowering is inhibited by withdrawal of nutrients, primarily carbohydrates, by apple fruit is questionable, given the effects of seed development in inhibiting flowering in facultatively parthenocarpic (normally seedless) apple cultivars. The hypothesis that seeds inhibit flowering by exporting hormones, chiefly gibberellins (GAs), is an attractive one, given a) the effects of application of GAs in inhibiting flowering and b) the high concentrations of GAs in seeds. However, an alternative hypothesis, namely that seeds compete with apices for hormones that are required for flowering, is equally tenable.

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Climate Change and Eutrophication: A Short Review

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.2392 ◽

2018 ◽

Vol 8 (6) ◽

pp. 3668-3672

Author(s):

M. Nazari Sharabian ◽

S. Ahmad ◽

M. Karakouzian

Keyword(s):

Climate Change ◽

Water Resources ◽

Algal Blooms ◽

Climatic Factors ◽

Short Review ◽

Human Beings ◽

Nitrogen And Phosphorus ◽

Factors Affecting ◽

High Concentrations ◽

Water Eutrophication

Water resources are vital not only for human beings but essentially all ecosystems. Human health is at risk if clean drinking water becomes contaminated. Water is also essential for agriculture, manufacturing, energy production and other diverse uses. Therefore, a changing climate and its potential effects put more pressure on water resources. Climate change may cause increased water demand as a result of rising temperatures and evaporation while decreasing water availability. On the other hand, extreme events as a result of climate change can increase surface runoff and flooding, deteriorating water quality as well. One effect is water eutrophication, which occurs when high concentrations of nutrients, such as nitrogen and phosphorus, are present in the water. Nutrients come from different sources including agriculture, wastewater, stormwater, and fossil fuel combustion. Algal blooms can cause many problems, such as deoxygenation and water toxicity, ultimately disrupting normal ecosystem functioning. In this paper, we investigate the potential impacts of climatic factors affecting water eutrophication, how these factors are projected to change in the future, and what their projected potential impacts will be.

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Trace Metal Distribution in Sulfide Minerals from Ultramafic-Hosted Hydrothermal Systems: Examples from the Kairei Vent Field, Central Indian Ridge

Minerals ◽

10.3390/min8110526 ◽

2018 ◽

Vol 8 (11) ◽

pp. 526 ◽

Cited By ~ 2

Author(s):

Yejian Wang ◽

Xiqiu Han ◽

Sven Petersen ◽

Matthias Frische ◽

Zhongyan Qiu ◽

...

Keyword(s):

Trace Elements ◽

Trace Element ◽

Massive Sulfide ◽

Sulfide Minerals ◽

Hydrothermal Systems ◽

The Other ◽

Central Indian Ridge ◽

Sulfide Deposits ◽

High Concentrations ◽

Seafloor Massive Sulfide

The ultramafic-hosted Kairei vent field is located at 25°19′ S, 70°02′ E, towards the Northern end of segment 1 of the Central Indian Ridge (CIR-S1) at a water depth of ~2450 m. This study aims to investigate the distribution of trace elements among sulfide minerals of differing textures and to examine the possible factors controlling the trace element distribution in those minerals using LA-ICP-MS spot and line scan analyses. Our results show that there are distinct systematic differences in trace element distributions throughout the different minerals, as follows: (1) pyrite is divided into three types at Kairei, including early-stage euhedral pyrite (py-I), sub-euhedral pyrite (py-II), and colloform pyrite (py-III). Pyrite is generally enriched with Mo, Au, As, Tl, Mn, and U. Pyrite-I has high contents of Se, Te, Bi, and Ni when compared to the other types; py-II is enriched in Au relative to py-I and py-III, but poor in Ni; py-III is enriched in Mo, Pb, and U but is poor in Se, Te, Bi, and Au relative to py-I and py-II. Variations in the concentrations of Se, Te, and Bi in pyrite are most likely governed by the strong temperature gradient. There is generally a lower concentration of nickel than Co in pyrite, indicating that our samples precipitated at high temperatures, whereas the extreme Co enrichment is likely from a magmatic heat source combined with an influence of serpentinization reactions. (2) Chalcopyrite is characterized by high concentrations of Co, Se, and Te. The abundance of Se and Te in chalcopyrite over the other minerals is interpreted to have been caused by the high solubilities of Se and Te in the chalcopyrite lattice at high temperatures. The concentrations of Sb, As, and Au are relatively low in chalcopyrite from the Kairei vent field. (3) Sphalerite from Zn-rich chimneys is characterized by high concentrations of Sn, Co, Ga, Ge, Ag, Pb, Sb, As, and Cd, but is depleted in Se, Te, Bi, Mo, Au, Ni, Tl, Mn, Ba, V, and U in comparison with the other minerals. The high concentrations of Cd and Co are likely caused by the substitution of Cd2+ and Co2+ for Zn2+ in sphalerite. A high concentration of Pb accompanied by a high Ag concentration in sphalerite indicates that Ag occurs as Pb–Ag sulfosalts. Gold is generally low in sphalerite and strongly correlates with Pb, suggesting its presence in microinclusions of galena. The strong correlation of As with Ge in sphalerite from Kairei suggests that they might precipitate at medium temperatures and under moderately reduced conditions. (4) Bornite–digenite has very low concentrations of most trace elements, except for Co, Se, and Bi. Serpentinization in ultramafic-hosted hydrothermal systems might play an important role in Au enrichment in pyrite with low As contents. Compared to felsic-hosted seafloor massive sulfide deposits, sulfide minerals from ultramafic-hosted deposits show higher concentrations of Se and Te, but lower As, Sb, and Au concentrations, the latter often attributed to the contribution of magmatic volatiles. As with typical ultramafic-hosted seafloor massive sulfide deposits, Se enrichment in chalcopyrite from Kairei indicates that the primary factor that controls the Se enrichment is temperature-controlled mobility in vent fluids.

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Production of tricarballylic acid by rumen microorganisms and its potential toxicity in ruminant tissue metabolism

British Journal Of Nutrition ◽

10.1079/bjn19860095 ◽

1986 ◽

Vol 56 (1) ◽

pp. 153-162 ◽

Cited By ~ 19

Author(s):

James B. Russell ◽

Neil Forsberg

Keyword(s):

Citric Acid ◽

Citric Acid Cycle ◽

Competitive Inhibitor ◽

Rumen Microorganisms ◽

Aconitate Hydratase ◽

Factors Affecting ◽

Acid Cycle ◽

Rat Liver Cells ◽

High Concentrations

1. Rumen microorganisms convert trans-aconitate to tricarballylate. The following experiments describe factors affecting the yield of tricarballylate, its absorption from the rumen into blood and its effect on mammalian citric acid cycle activity in vitro.2. When mixed rumen microorganisms were incubated in vitro with Timothy hay (Phleum praiense L.) and 6.7 mM-trans-aconitate, 64 % of the trans-aconitate was converted to tricarballylate. Chloroform and nirate treatments inhibited methane production and increased the yield of tricarballylate to 82 and 75% respectively.3. Sheep given gelatin capsules filled with 20 g trans-aconitate absorbed tricarballylate and the plasma concentration ranged from 0.3 to 0.5 mM 9 h after administration. Feeding an additional 40 g potassium chloride had little effect on plasma tricarballylate concentrations. Between 9 and 36 h there was a nearly linear decline in plasma tricarballylate.4. Tricarballylate was a competitive inhibitor of the enzyme, aconitate hydratase (aconitase; EC 4.2.1.3), and the inhibitor constant, KI, was 0.52 mM. This KIvalue was similar to the Michaelis-Menten constant (Km) of the enzyme for citrate.5. When liver slices from sheep were incubated with increasing concentrations of tricarballylate, [I4C]acetate oxidation decreased. However, even at relatively high concentrations (8 mM), oxidation was still greater than 80% of the maximum. Oxidation of [I4C]acetate by isolated rat liver cells was inhibited to a greater extent by tricarballylate. Concentrations as low as 0.5 mM caused a 30% inhibition of citric acid cycle activity.

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Assessment of Microbial Adhesion in Mixed Cultures to Sulfide Minerals Using CARD-FISH Techniques

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.71-73.83 ◽

2009 ◽

Vol 71-73 ◽

pp. 83-86 ◽

Cited By ~ 6

Author(s):

A. Echeverría ◽

Cecilia Demergasso

Keyword(s):

Fluorescent In Situ Hybridization ◽

Culture Medium ◽

Sulfide Minerals ◽

Acidithiobacillus Thiooxidans ◽

Mineral Surfaces ◽

Dapi Staining ◽

Factors Affecting ◽

Catalyzed Reporter Deposition ◽

Card Fish

The adhesion of microorganisms to minerals is one of the least understood aspects of bioleaching processes. Mineral and microorganism type are determinant factors affecting the capacity of a microbial community to form biofilms in these processes. In this paper the adhesion capacity of different microorganisms to different copper sulfide minerals generally present in bioleaching processes was studied. The minerals, chalcosite, chalcopyrite and pyrite were used and the composition of the microbial population which adhered to the mineral surfaces was determined using the Catalyzed Reporter Deposition Fluorescent In Situ Hybridization (CARD-FISH) technique. This technique involves the fluorescent marking of the cells using specific DNA probes and their observation with a confocal microscope. Three probes were used against the microorganisms: Acidithiobacillus ferooxidans, Acidithiobacillus thiooxidans and Leptospirillum. Polished fragments of the three minerals were placed in a tube with a culture medium which was inoculated with cells from a mixed culture capable of growing at 25°C. The adhered microorganisms were counted with CARD-FISH and compared with the total count which was carried out with DAPI staining. The results show that microorganisms adhered indistinctly to pyrite and chalcopyrite but not chalcosite. It was also observed that in pyrite 60% of the adhered microorganisms were Acidithiobacillus thiooxidans, 35% Acidithiobacillus ferrooxidans, and 1 % Leptospirillum. The remaining 4% were unidentified microorganisms.

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