scholarly journals Iron Speciation and Physiological Analysis Indicate that Synechococcus sp. PCC 7002 Reduces Amorphous and Crystalline Iron Forms in Synthetic Seawater Medium

2020 ◽  
Vol 8 (12) ◽  
pp. 996
Author(s):  
Annie Vera Hunnestad ◽  
Anne Ilse Maria Vogel ◽  
Maria Guadalupe Digernes ◽  
Murat Van Ardelan ◽  
Martin Frank Hohmann-Marriott
Keyword(s):  
Physiochemical Properties ◽  
Synthetic Seawater ◽  
Dissolved Iron ◽  
Reduction Of Iron ◽  
Physiological Analysis ◽  
Synechococcus Sp ◽  
High Concentrations ◽  
Iron Pool ◽  
Low Solubility ◽  
Iron Forms

Cyanobacteria have high iron requirements due to iron-rich photosynthetic machineries. Despite the high concentrations of iron in the Earth’s crust, iron is limiting in many marine environments due to iron’s low solubility. Oxic conditions leave a large portion of the ocean’s iron pool unavailable for biotic uptake, and so the physiochemical properties of iron are hugely important for iron’s bioavailability. Our study is the first to investigate the effect of iron source on iron internalization and extracellular reduction by Synechococcus sp. PCC 7002. The results indicated that the amorphous iron hydrolysis species produced by FeCl3 better support growth in Synechococcus through more efficient iron internalization and a larger degree of extracellular reduction of iron than the crystalline FeO(OH). An analysis of dissolved iron (II) indicated that biogenic reduction took place in cultures of Synechococcus grown on both FeCl3 and FeO(OH).

scholarly journals An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean)

2009 ◽  
Vol 6 (4) ◽  
pp. 6803-6837 ◽  
Author(s):  
F. Chever ◽  
G. Sarthou ◽  
E. Bucciarelli ◽  
S. Blain ◽  
A. R. Bowie
Keyword(s):  
Southern Ocean ◽  
Dissolved Iron ◽  
Heard Island ◽  
Natural Iron ◽  
Particulate Iron ◽  
The Difference ◽  
The One ◽  
Iron Pool ◽  
Lateral Advection ◽  
Very High

Abstract. Total dissolvable iron (TDFe) was measured in the water column above and in the surrounding of the Kerguelen Plateau (Indian sector of the Southern Ocean) during the KErguelen Ocean Plateau compared Study (KEOPS) cruise. TDFe concentrations ranged from 0.90 to 65.6 nmol L−1 above the plateau and from 0.34 to 2.23 nmol L−1 offshore of the plateau. Station C1 located south of the plateau, near Heard Island, exhibited very high values (329–770 nmol L−1). Apparent particulate iron (Feapp), calculated as the difference between the TDFe and the dissolved iron measured on board (DFe) represented 95±5% of the TDFe above the plateau, suggesting that particles and refractory colloids largely dominated the iron pool. This paper presents a budget of DFe and Feapp above the plateau. Lateral advection of water that had been in contact with the continental shelf of Heard Island seems to be the predominant source of Feapp and DFe above the plateau, with a supply of 9.7±2.3×106 and 8.3±6.7×103 mol d−1, respectively. The residence times of 1.7 and 48 days estimated for Feapp and DFe, respectively, indicate a rapid turnover in the surface water. A comparison between Feapp and total particulate iron (TPFe) suggests that the total dissolved fraction is mainly constituted of small refractory colloids. This fraction does not seem to be a potential source of iron to the phytoplankton in our study. Finally, when taking into account the lateral supply of dissolved iron, the seasonal carbon sequestration efficiency was estimated at 154 000 mol C (mol Fe)−1, which is 4-fold lower than the previously estimated value in this area but still 18-fold higher than the one estimated during the other study of a natural iron fertilisation experiment, CROZEX.

ASSESSMENT OF HEAVY METAL CONTAMINATION OF SOIL SAMPLES COLLECTED FROM THE AREA AROUND AL-MARQUB CEMENT PLANT

2019 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Dr. Salem M. ELNakeib ◽  
Dr. Fathi K. Elyaagubi ◽  
Dr. Mohamed A. Alrabib ◽  
Eng. Afaf Abouzed ◽  
Eng. Hanan Saleh Wanis
Keyword(s):  
Heavy Metal ◽  
Soil Properties ◽  
Heavy Metal Contamination ◽  
Calcium Content ◽  
Heavy Metal Concentration ◽  
Soil Samples ◽  
Cement Dust ◽  
Physiochemical Properties ◽  
Cement Factory ◽  
High Concentrations

Soil samples were collected from and around Almarqub cement factory, AL-Khums city, Libya. These samples were collected from four different sites M1 (inside the factory), M2 (150 m from the factory), M3 (350 m from the factory) and M4 (60 km away from the factory as the control samples. The study was conducted to determine the heavy metal concentration in the soil. Organic matter, pH and water content value were determined according to the method described by Chaturvedi and Sankar (2006). Metals were determined by Atomic Absorption Spectrophotometer. The results obtained for the examined physiochemical properties of soil in the area studied prove that cement dust from the Almarqub cement factory has had a significant impact on the soil. The affected soil properties are pH and total calcium content. These properties were found to be higher than those in similar soils from the same area unpolluted. The increase of soil pH in the same area may be a result of precipitation of cement dust over the years. Metal uptake from cement to soil and plants. Metals determined in contamination soil indicated high concentrations in M1 inside cement factory compared to soil samples as control. Results of the analysis have shown that there are signs of slight impact of soil properties arising from the cement dust on the soils, especially at location inside the factory. Recommendations were offered to monitor the dust falling on the soils through trapping and utilizing the dust emissions of cement.

scholarly journals GENETIC AND PHYSIOLOGICAL ANALYSIS OF SUCROSE ACCUMULATION IN TOMATO FRUIT

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 584b-584
Author(s):  
John R. Stommnel
Keyword(s):  
Tomato Fruit ◽  
Sugar Content ◽  
Recessive Gene ◽  
Sucrose Phosphate Synthase ◽  
Soluble Solids ◽  
Sucrose Accumulation ◽  
Backcross Populations ◽  
Physiological Analysis ◽  
High Concentrations ◽  
High Level

Fruit of the cultivated tomato, Lycopersicon esculentum, accumulate the reducing sugars glucose and fructose as the primary storage carbohydrates. In contrast, fruit of several wild green-fruited species store high concentrations of sucrose. Analysis of invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS) enzyme activity throughout fruit development in the sucrose accumulating species L. peruvianum, indicated low levels of invertase and SS during the period of significant sucrose accumulation. Increased SPS activity was noted during the sucrose accumulation phase but was not coincident with maximum rates of sucrose accumulation. The percent soluble solids in ripe L. peruvianum fruit was more than twice that present in L. esculentum and attributed primarily to the high level of sucrose accumulated in L. peruvianum. Analysis of fruit sugar content in F1, F2 and backcross populations derived from an initial cross between plants of sucrose and hexose accumulators suggests that recessive gene(s) are responsible for sucrose accumulation.

scholarly journals Atmospheric Iron and Aluminium Deposition and Sea-Surface Dissolved Iron and Aluminium Concentrations in the South China Sea off Malaysia Borneo (Sarawak Waters)

2021 ◽  
Vol 11 (2) ◽  
pp. 76-87
Author(s):  
Farah Akmal Idrus ◽  
Khairul Nizam Mohamed ◽  
Nur Syazwani Abdul Rahim ◽  
Melissa Dennis Chong
Keyword(s):  
South China Sea ◽  
Southeast Asia ◽  
South China ◽  
Organic Ligand ◽  
Dust Deposition ◽  
High Concentration ◽  
China Sea ◽  
Dissolved Iron ◽  
Haze Event ◽  
High Concentrations

South China Sea (SCS) is an oligotrophic sea which usually receives low nutrients supply. However, massive atmospheric dust input was occurred during the haze event in Southeast Asia for almost every year. The input of dissolved iron (DFe) and dissolved aluminium (DAl) from dust and nearby land into SCS off Sarawak Borneo region during the worst haze event in 2015 of the Southeast Asia were investigated. The estimation dust deposition during this study was 0.162 mg/m2/yr. The atmospheric fluxes of total Fe and total Al at the offshore Sarawak waters were 0.611 µmol/m2/yr and 2.03 µmol/m2/yr, respectively, where the readily available dissolved Fe and Al from the dust were 0.11 µmol/m2/yr (DFe) and 0.31 µmol/m2/yr (DAl). Fe has higher solubility (17.78%) than Al (15.21%). The lateral fluxes (e.g. from the nearby land) were 37.08 nmol/m2/yr (DFe) and 125 nmol/m2/yr (DAl), with strong Fe organic ligand class L1 (log K:22.43 – 24.33). High concentrations of DFe and DAl at the surface water of the offshore region, coincided with high concentration of macronutrients due to the prevailing south-westerly winds originated from the west Kalimantan. Low residence times, ~0.92 (DFe) and ~1.31 (DAl) years, corresponded well with DAlexcess in surface seawater due to biological utilization of DFe. Future works emphasize on natural organic Fe(III) ligands and phytoplankton study are needed for better understanding on biogeochemistry of Fe and Al at SCS off Malaysia Borneo.

scholarly journals An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean)

2010 ◽  
Vol 7 (2) ◽  
pp. 455-468 ◽  
Author(s):  
F. Chever ◽  
G. Sarthou ◽  
E. Bucciarelli ◽  
S. Blain ◽  
A. R. Bowie
Keyword(s):  
Southern Ocean ◽  
Dissolved Iron ◽  
Heard Island ◽  
Natural Iron ◽  
Particulate Iron ◽  
The Difference ◽  
The One ◽  
Iron Pool ◽  
Lateral Advection ◽  
Very High

Abstract. Total dissolvable iron (TDFe) was measured in the water column above and in the surrounding of the Kerguelen Plateau (Indian sector of the Southern Ocean) during the KErguelen Ocean Plateau compared Study (KEOPS) cruise. TDFe concentrations ranged from 0.90 to 65.6 nmol L−1 above the plateau and from 0.34 to 2.23 nmol L−1 offshore of the plateau. Station C1 located south of the plateau, near Heard Island, exhibited very high values (329–770 nmol L−1). Apparent particulate iron (Feapp), calculated as the difference between the TDFe and the dissolved iron measured on board (DFe) represented 95±5% of the TDFe above the plateau, suggesting that particles and refractory colloids largely dominated the iron pool. This paper presents a budget of DFe and Feapp above the plateau. Lateral advection of water that had been in contact with the continental shelf of Heard Island seems to be the predominant source of Feapp and DFe above the plateau, with a supply of 9.7±3.6×106 and 8.3±11.6×103 mol d−1, respectively. The residence times of 1.7 and 48 days estimated for Feapp and DFe respectively, indicate a rapid turnover in the surface water. A comparison between Feapp and total particulate iron (TPFe) suggests that the total dissolved fraction is mainly constituted of small refractory colloids. This fraction does not seem to be a potential source of iron to the phytoplankton in our study. Finally, when taking into account the lateral supply of dissolved iron, the seasonal carbon sequestration efficiency was estimated at 154 000 mol C (mol Fe)−1, which is 4-fold lower than the previously estimated value in this area but still 18-fold higher than the one estimated during the other study of a natural iron fertilisation experiment, CROZEX.

The early diagenesis of submerged sulphide-rich mine tailings in Anderson Lake, Manitoba

1993 ◽  
Vol 30 (6) ◽  
pp. 1099-1109 ◽  
Author(s):  
T. F. Pedersen ◽  
B. Mueller ◽  
J. J. McNee ◽  
C. A. Pelletier
Keyword(s):  
Mine Tailings ◽  
Mine Drainage ◽  
Pore Waters ◽  
Widespread Occurrence ◽  
Dissolved Iron ◽  
The North ◽  
Acidophilic Bacteria ◽  
Permanent Storage ◽  
High Concentrations ◽  
Interstitial Waters

The oxidation of sulphide-rich mine tailings stored on land by acidophilic bacteria is frequently associated with severe environmental degradation, as metal-rich acid drainage from the tailings contaminates groundwater and surface runoff. Permanent storage of tailings underwater may prove to be more chemically benign if oxidation is inhibited sufficiently. To assess this possibility, the chemistry of interstitial waters and the associated solid phases in tailings and organic-rich (20–30 wt.% C) natural sediments in Anderson Lake, Manitoba, is examined. The lake has been used as a receiving basin for sulphide-rich tailings since 1979, and is contaminated with metals as a result of the input of acid mine drainage along the north shore and the discharge of mill process water with the tailings. Three cores were collected and processed under nitrogen to extract interstitial waters. At all sites, the occurrence of high concentrations of dissolved iron in shallow pore waters indicates that the deposits are anoxic within several millimetres of the sediment–water interface. Despite high dissolved metal inventories in the lake, the concentrations of Zn, Cu, Pb, and Cd decrease abruptly with depth in the pore waters. This cannot be due to non-steady-state effects and indicates unequivocally that both the tailings and natural sediments are acting as sinks for metals, rather than as sources. Dissolved sulphate data and the widespread occurrence of framboidal pyrite in surface sediments suggest that the metals are being precipitated as sulphide phases at shallow depths.

Nutrient effects on growth and the production of 5-hydroxy-4-oxonorvaline by Streptomyces akiyoshiensis

1993 ◽  
Vol 39 (5) ◽  
pp. 536-542 ◽  
Author(s):  
M. A. Glazebrook ◽  
L. C. Vining ◽  
R. L. White ◽  
K. C. Smith ◽  
E. G. Chedrawy
Keyword(s):  
Nitrogen Sources ◽  
Potassium Nitrate ◽  
Nutrient Effects ◽  
Magnesium Ammonium ◽  
Initial Ph ◽  
Physiological Analysis ◽  
Poorly Soluble ◽  
High Concentrations ◽  
High Level ◽  
Inorganic Constituents

5-Hydroxy-4-oxonorvaline (HON) was produced optimally by Streptomyces akiyoshiensis in media containing starch and casein supplemented with high concentrations of phosphate and magnesium sulfate; cultures grown at initial pH values between 6.3 and 6.6 yielded HON titres of 13–14 mM. Physiological analysis of HON production provided evidence that the excess inorganic constituents in this medium played an important role in optimizing production. In simple defined media buffered at pH 5.5–6.0 and inoculated with either a spore suspension or washed vegetative mycelium, formation of HON was less than one-third the amount produced in the starch–casein–salts medium. Production was markedly affected by the carbon and nitrogen sources used; media containing starch and potassium nitrate or aspartate supported the highest yields of HON. In starch–nitrate media, production was suppressed by excess nitrogen source, and the HON titre decreased 3-fold as the phosphate content was increased from 0.5 to 5 mM; growth was not appreciably altered. The results suggest that the high level of HON production in the complex starch–casein–salts medium is associated with sequestration of metabolic ammonium and reduced availability of phosphate through formation of the poorly soluble magnesium ammonium phosphate.Key words: Streptomyces akiyoshiensis, 5-hydroxy-4-oxonorvaline, nitrogen catabolite regulation, phosphate suppression.

scholarly journals Respuestas fisiológicas de Zea mays durante la infección por Ustilago maydis bajo diferentes concentraciones de humus en suelo

2019 ◽  
pp. 1-7
Author(s):  
Lucila Méndez-Morán ◽  
Iván David Meza-Canales ◽  
Celia Robles-Murguía ◽  
América Loza-Llamas
Keyword(s):  
Zea Mays ◽  
Plant Growth ◽  
Plant Development ◽  
Agricultural Practices ◽  
Ustilago Maydis ◽  
Fungus Infection ◽  
Negative Effect ◽  
Physiological Analysis ◽  
High Concentrations ◽  
Humus Soil

The available resources during plant development, sometimes plant can be limited due to energy used during physiological plant defense to pathogens attacks. The main of this work was the physiological analysis of Zea mays plants development under different sustainable fertilization systems, as the earthworm-humus, and their relation with the response to Ustilago maydis infection, a biotrophyc fungus that causes the disease known as common coal or cuitlacoche in corn. Mize seedlings developed with different % of humus/soil under greenhouse conditions were inoculated with U. maydis (T1), and plants not inoculated as control (T0). Physiological and growth measurements in T1 showed a significant effect on the plant, the best was a 25%. After infection, the plants growth was lower as a result in decrease in photosynthesis activity, however, the presence of humus partially counteracts the fungus infection. High concentrations of humus reflected a negative effect on plant growth. In the future, the studies in the field will serve to deduce the importance of these agricultural practices in plant-fungus responses.

scholarly journals Alkaline Dehydration of Human Urine Collected in Source-Separated Sanitation Systems Using Magnesium Oxide

2021 ◽  
Vol 8 ◽  
Author(s):  
Prithvi Simha ◽  
Christopher Friedrich ◽  
Dyllon Garth Randall ◽  
Björn Vinnerås
Keyword(s):  
Wheat Bran ◽  
Human Urine ◽  
Molecular Diffusion ◽  
N Recovery ◽  
Mass Reduction ◽  
High Concentrations ◽  
Sanitation Systems ◽  
Hydrolysis Of ◽  
Low Solubility ◽  
Fresh Urine

Fresh human urine, after it is alkalized to prevent the enzymatic hydrolysis of urea, can be dehydrated to reduce its volume and to produce a solid fertilizer. In this study, we investigated the suitability of MgO to alkalize and dehydrate urine. We selected MgO due to its low solubility (<2 g·L−1) and relatively high saturation pH (9.9 ± 0.2) in urine. Using a laboratory-scale setup, we dehydrated urine added to pure MgO and MgO mixed with co-substrates (biochar, wheat bran, or calcium hydroxide) at a temperature of 50°C. We found that, dehydrating urine added to a mixture of MgO (25% w/w), biochar, and wheat bran resulted in a mass reduction of >90% and N recovery of 80%, and yielded products with high concentrations of macronutrients (7.8% N, 0.7% P and 3.9% K). By modeling the chemical speciation in urine, we also showed that ammonia stripping rather than urea hydrolysis limited the N recovery, since the urine used in our study was partially hydrolyzed. To maximize the recovery of N during alkaline urine dehydration using MgO, we recommend treating fresh/un-hydrolysed urine a temperature <40°C, tailoring the drying substrate to capture NH4+ as struvite, and using co-substrates to limit the molecular diffusion of ammonia. Treating fresh urine by alkaline dehydration requires only 3.6 kg MgO cap−1y−1 and a cost of US$ 1.1 cap−1y−1. Therefore, the use of sparingly soluble alkaline compounds like MgO in urine-diverting sanitation systems holds much promise.

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