Effect of coexisting metal ions on bio-precipitation of Cu2+ phosphate by Rahnella sp. LRP3 and its stability in soil

The phosphate precipitation of heavy metal induced by microorganisms plays an important role in immobilising heavy metal in soil. However, there is little knowledge about the effect of coexisting metal ions on the induction of Cu phosphate mineral and its stability. In this paper, the Cu phosphate precipitations, coexisting with Pb²⁺ or Ca²⁺ induced by strain LRP3, were characterised, and the stabilisation of the induced phosphate precipitates was also studied. The coexistence of Cu with Pb or Ca decreased the removal efficiency of Cu²⁺ by 17.18% and 9.78%, respectively, indicating the competitive adsorption between cations. Strain LRP3 could induce a new phosphate mineral of CuCa₁₀(PO₄)₇ when coexisting with Ca and also generate the phosphate minerals of Pb(H₂PO₄)₂ and Cu₃(PO₄)₂ when coexisting with Pb. The Cu-Ca coprecipitate could enhance the stability of Cu in dilute acid solution and soil with or without a plant, whiles the Cu-Pb one showed the opposite effect. Also, the Cu-induced phosphate precipitates were relatively stable and not easy to be absorbed by Pakchoi (Brassica rapa var. chinensis). The results showed that the influence of coexisting metal ions should be considered when phosphate mineralisation technology is used to immobilise heavy metals in the environment.

Evaluation of Potato Varieties Grown in Hydroponics for Phosphorus Use Efficiency

Global phosphate mineral resources are nonrenewable and are inevitably depleting. Exploiting elite varieties has become imperative for the efficient use of phosphorus (P) for sustainable crop production. Three potato varieties were hydroponically evaluated for P mobilization, uptake, and utilization efficiencies at different P levels and sources during 28 d seedling growth. ‘Harley Blackwell’, ‘La Chipper’, and ‘Red LaSoda’ were selected from a previous study and grown in modified Hoagland solution, with different P concentrations of soluble high P as NaH2PO4 (10 mg L−1 P), soluble low P (1 mg L−1 P), and 286 mg L−1 sparingly soluble P as tri-calcium phosphate [TCP, Ca3(PO4)2] with 2286 mg L−1 CaSO4. ‘Harley Blackwell’ and ‘La Chipper’ had significantly greater biomass than ‘Red LaSoda’ in the low P or TCP treatments. In low-P stress, P utilization efficiency was significantly greater for ‘Harley Blackwell’ than that of the other two varieties. ‘Red LaSoda’ was more efficient in P mobilization from TCP as compared to the other two cultivars. The holistic score analysis indicated that ‘Harley Blackwell’ was the most P-efficient while ‘Red LaSoda’ was the least P-efficient. The results of this study show that the TCP solution was successful for screening P-efficient potato varieties.

Liraite, ideally NaCa2Mn2[Fe3+Fe2+]Mn2(PO4)6(H2O)2, a new phosphate mineral of the wicksite group from the Ceferino Namuncurá pegmatite, Córdoba, Argentina

ABSTRACT Liraite, ideally NaCa2Mn2[Fe3+Fe2+]Mn2(PO4)6(H2O)2, is a new mineral found in the Ceferino Namuncurá pegmatite, Pocho Department, Córdoba province, Argentina. It occurs in ellipsoidal nodules up to 20 cm in diameter in the intermediate zone of a Muscovite-Rare Element class pegmatite. Secondary phosphates, such as varulite, robertsite, fluorapatite, phosphosiderite, and Sr-rich metaswitzerite, together with minor quartz in veinlets, are associated minerals. Liraite is interpreted to have formed by reaction of phosphate minerals with Na-bearing hydrothermal fluids. It is dark brown with greenish hues (nearly black) in massive aggregates and dark olive green in translucent slices with a dark brownish green streak and a vitreous luster. It is brittle with an irregular fracture, one very good cleavage, and a good cleavage orthogonal to the very good cleavage. The Mohs hardness is 5, and the measured and calculated densities are 3.52(1) and 3.529(1) g/cm3, respectively. In transmitted light it is pleochroic X = Y = olive, Z = yellowish brown with X = Y > Z and optical orientation X = 2V(calc.) = 69.2°. The refractive indicies measured with monochromatic light (λ = 589 nm) are α = 1.732 (3), β = 1.739 (3), γ = 1.754 (3). Liraite is orthorhombic (Pcab) and has unit-cell parameters a = 12.608(6) Å, b = 12.918(6) Å, c = 11.737(4) Å, V = 1911.6(14) Å3, Z = 4. The six strongest reflections in the X-ray powder diffraction pattern are as follows: [d in Å, (I), (hkl)] 2.7452, 100, (421); 2.8563, 65, (014); 2.9266, 49, (004); 2.7061, 30, (412); 2.0966, 29, (334); 2.7693, 26, (402). The crystal structure was refined to an R index of 1.94% based on 2910 observed (>4σF) reflections measured with MoKα X-radiation. Chemical analysis by electron microprobe of the structure crystal (holotype specimen) gave Na2O 1.58, FeO 5.29, Fe2O3 11.45, CaO 10.52, MgO 0.77, MnO 24.00, P2O5 41.55, SrO 0.72, ZnO 0.19, H2O (calc.) 3.50, total 99.57 wt.% where water was calculated from the crystal-structure analysis and the Fe3+/Fe2+ ratio was determined by charge balance. The empirical formula calculated on the basis of 26 oxygen atoms is (Na0.53□0.47)Σ1.00(Ca1.93Sr0.07)Σ2.00(Fe3+1.48Fe2+0.76Mn3.48Mg0.20Zn0.02)Σ5.94P6.02O24(H2O)2, ideally NaCa2M(1)Mn2M(2)[Fe3+Fe+2]M(3)Mn2(PO4)6(H2O)2. The Gladstone-Dale relation gives a compatibility index of 1 – (KP/KC) = 0.010 (superior). This new member of the wicksite group is Mn-rich, and, like bederite, has Mn dominant at the M(1) and M(3) sites. However, the Na site in liraite is Na-dominant with M(2)[Fe3+Fe2+], whereas bederite is □-dominant with M(2)Fe3+2. Liraite has a very low MgO content, and even with all available Mg assigned to the M(2) site, Fe2+ > Mg at M(2). Consequently, liraite is the first wicksite-group mineral with endmember M(2) composition [Fe3+Fe2+].

MO569MACROPHAGE PROMOTE VASCULAR CALCIFICATION VIA THE MIGRASOMES/ INTEGRIN Α5Β1 PATHWAY IN CKD

Background and Aims Patients with chronic kidney disease (CKD) have a predisposition to develop vascular calcification due to dysregulated homeostatic mechanisms. Macrophages can promote vascular calcification by releasing diverse extracellular vehicles including the newly found migrasomes (M-mig). Our previous research had found that M-mig provide nucleating foci for calcific mineral formation and initiating bone mineralization process. However, the specific mechanism by which M-mig influence the formation of vascular calcification remains incompletely understood. Method To study calcifying M-mig, we exposed M-mig to high Ca/P (Ca/P=3 mmol/L calcium/2 mmol/L phosphate) and/or with LPS for 1, 3, 5,7 days. The expression of M-mig surface integrin α5β1 was determined by fluorescence staining. To block the M-mig-integrin α5β1 mediated calcification, we modulated the expression of integrin α5 using siRNAs to produce M-migintegrin α5- or using 20 nM ATN-161 (small peptide antagonist of integrin α5β1) or integrin α5 antibody under high Ca/P stimulation. The stray mice artery co-cultivate with M-mig integrin α5- under high level Ca/P. Then the calcifying M-mig were assessed by TEM, Fluo-3 staining and calcium content assay. Results We discovered that Ca/P-stimulated macrophages released M-mig capable of mineralization. Amorphous calcium phosphate mineral deposit the surface or internal of M-mig. The M-mig exhibited increased Ca/P mineral content, implying aggregate larger calcifying M-mig that develop over time. Significantly, following a 7 days incubation with high level Ca/P, fiber tube and vesicle structure of M-mig showed rupture or fragmentation and the expression of M-mig surface integrin α5β1 increased. Pre-treatment with integrin α5β1 antagonist or block by integrin α5 antibody significantly reduced the calcifying M-mig formation. Further investigation showed that M-mig induced stray mice artery microcalcification while M-migintegrin α5- exhibited a reduce microcalcification. Conclusion Our finding revealed an association between microcalcification and integrin α5β1 signalling in the fiber tube and vesicle structure of M-mig and provide a new insight into vascular calcification in CKD.

Monazite Microstructures and Their Interpretation in Petrochronology

The phosphate mineral monazite (LREE,Y,Th,Ca,Si)PO4 occurs as an accessory phase in peraluminous granites and Ca-poor meta-psammopelites. Due to negligible common Pb and very low Pb diffusion rates at high temperatures, monazite has received increasing attention in geochronology. As the monazite grain sizes are mostly below 100 μm in upper greenschist to amphibolite facies meta-psammopelites, and rarely exceed 250 μm in granulite facies gneisses and in migmatites, microstructural observation and mineral chemical analysis need the investigation by scanning electron microscope and electron probe microanalyzer, with related routines of automated mineralogy. Not only the microstructural positions, sizes and contours of the grains, but also their internal structures in backscattered electron imaging gray tones, mainly controlled by the Th contents, can be assessed by this approach. Monazite crystallizes mostly euhedral to anhedral with more or less rounded crystal corners. There are transitions from elliptical over amoeboid to strongly emarginated grain shapes. The internal structures of the grains range from single to complex concentric over systematic oszillatory zonations to turbulent and cloudy, all with low to high contrast in backscattered electron imaging gray tones. Fluid-mediated partial alteration and coupled dissolution-reprecipitation can lead to Th-poor and Th-rich rim zones with sharp concave boundaries extending to the interior. Of particular interest is the corona structure with monazite surrounded by apatite and allanite, which is interpreted to result from a replacement during retrogression. The satellite structure with an atoll-like arrangement of small monazites may indicate re-heating after retrogression. Cluster structures with numerous small monazite grains, various aggregation structures and coating suggest nucleation and growth along heating or/and enhanced fluid activity. Microstructures of monazite fluid-mediated alteration, decomposition and replacement are strongly sutured grain boundaries and sponge-like porosity and intergrowth with apatite. Garnet-bearing assemblages allow an independent reconstruction of the pressure-temperature evolution in monazite-bearing meta-psammopelites. This provides additional potential for evaluation of the monazite microstructures, mineral chemistry and Th-U-Pb ages in terms of clockwise and counterclockwise pressure-temperature-time-deformation paths of anatectic melting, metamorphism and polymetamorphism. That way, monazite microstructures serve as unique indicators of tectonic and geodynamic scenarios.