scholarly journals Iron Oxalate Humboldtine Crystallization by Fungus Aspergillus niger

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1591
Author(s):  
Marina S. Zelenskaya ◽  
Alina R. Izatulina ◽  
Olga V. Frank-Kamenetskaya ◽  
Dmitry Y. Vlasov

Microfungi were able to alternate solid substrate in various environments and play a noticeable role in the formation of insoluble calcium oxalate crystals in subaerial biofilms on rock surfaces. The present work describes how iron oxalate dihydrate humboldtine is acquired under the influence of the acid-producing microscopic fungus Aspergillus niger on the surface of two iron- bearing mineral substrates in vitro. Pyrrhotite and siderite rocks, as well as the products of their alteration, were investigated using a complex of analytical methods, including powder X-ray diffraction, optical microscopy, scanning electron microscopy and EDX spectroscopy. The effect of the underlying rocks with different composition and solubility and different oxidation states of iron on Fe-oxalate crystallization and on the morphology of humboldtine crystals was shown. The mechanisms of humboldtine formation were discussed. The results obtained in vitro seem promising for using fungi in bioleaching iron and other metals from processed ores and for the development of environmentally friendly biotechnologies.

Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.


2010 ◽  
Vol 12 (4) ◽  
pp. 53-57 ◽  
Author(s):  
Agata Markowska-Szczupak ◽  
Krzysztof Ulfig ◽  
Barbara Grzmil ◽  
Antoni Morawski

A preliminary study on antifungal effect of TiO2-based paints in natural indoor light The antifungal activity of four commercial photocatalytic paints (KEIM Ecosil ME, Titanium FA, Photo Silicate and Silicate D) in natural indoor light was investigated. The paints contained TiO2 in rutile and anatase crystalline forms as evidenced by means of the X-ray diffraction analysis. In most cases the paints inhibited growth of fungi viz. Trichoderma viride, Aspergillus niger, Coonemeria crustacea, Eurotium herbariorum, and Dactylomyces sp. The KEIM Ecosil ME paint displayed the highest antifungal effect in the light, which could be explained with the highest anatase content. The paint antifungal activity and the fungal sensitivity to the TiO2-mediated photocatalytic reaction both decreased in the following orders: KEIM Ecosil ME > Titanium FA > Photo Silicate > Silicate D and T. viride > Dactylomyces sp. > A. niger > E. herbariorum.


Author(s):  
X Li ◽  
D Li ◽  
B Lu ◽  
L Wang ◽  
Z Wang

The ability to have precise control over internal channel architecture, porosity, and external shape is essential for tissue engineering. The feasibility of using indirect stereo-lithography (SL) to produce scaffolds from calcium phosphate cement materials for bone tissue engineering has been investigated. The internal channel architecture of the scaffolds was created by removal of the negative resin moulds made with SL. Scanning electron microscopy (SEM) showed highly open, well-interconnected channel architecture. The X-ray diffraction examination revealed that the hydroxyapatite phase formed at room temperature in the cement was basically stable up to 850 °C. There was no phase decomposition of hydroxyapatite, although the crystallinity and grain size were different. The ability of resulting structure to support osteoblastic cells culture was tested in vitro. Cells were evenly distributed on exterior surfaces and grew into the internal channels of scaffolds. To exploit the ability of this technique, anatomically shaped femoral supracondylar scaffolds with 300-800 μm interconnected channels were produced and characterized.


2007 ◽  
Vol 86 (1) ◽  
pp. 69-72 ◽  
Author(s):  
M. Kida ◽  
Y. Sakiyama ◽  
A. Matsuda ◽  
S. Takabayashi ◽  
H. Ochi ◽  
...  

Amelogenesis imperfecta (AI) is a hereditary disease with abnormal dental enamel formation. Here we report a Japanese family with X-linked AI transmitted over at least four generations. Mutation analysis revealed a novel mutation (p.P52R) in exon 5 of the amelogenin gene. The mutation was detected as heterozygous in affected females and as hemizygous in their affected father. The affected sisters exhibited vertical ridges on the enamel surfaces, whereas the affected father had thin, smooth, yellowish enamel with distinct widening of inter-dental spaces. To study the pathological cause underlying the disease in this family, we synthesized the mutant amelogenin p.P52R protein and evaluated it in vitro. Furthermore, we studied differences in the chemical composition between normal and affected teeth by x-ray diffraction analysis and x-ray fluorescence analysis. We believe that these results will greatly aid our understanding of the pathogenesis of X-linked AI.


2010 ◽  
Vol 17 (02) ◽  
pp. 153-157 ◽  
Author(s):  
N. R. HA ◽  
Z. X. YANG ◽  
G. C. KIM ◽  
K. H. HWANG ◽  
D. S. SEO ◽  
...  

Titanium alloys are superior of biocompatibility, mechanical properties and chemical stability. The biocompatibility of Ti alloy is related to the surface effect between human tissue and implant. Therefore, the purpose of this study is to investigate the bioactivity of Ti alloy by alkali and acid chemical surface treatment; and the biocompatibility of Ti alloy was evaluated by in vitro test. Higher bone-bonding ability and bioactivity of the substrate were obtained by the formation of apatite layers on the Ti alloy in simulated body fluid. The microstructures of apatite layer were investigated by scanning electron microscope (SEM) and the formed phases were analyzed with X-ray diffraction (XRD).


2015 ◽  
Vol 638 ◽  
pp. 67-72
Author(s):  
Ana Maria Salantiu ◽  
Florin Popa ◽  
Petru Pascuta ◽  
Olga Soritau ◽  
Noemi Dirzu ◽  
...  

This work aims to investigate the influence of surface conditioning of porous Ti for enhancing its biological activity, as assessed by in vitro stem cell testing. Porous Ti samples with an average porosity of 32% were processed by Powder Metallurgy with dextrin as a space holder. The samples were subjected to H2O2 treatment to form an enhanced TiO2 film, followed by a heat treatment at 400°C and 600°C aiming to the crystallization of the as-formed amorphous titanium oxide. Samples characterization was performed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The treated surfaces revealed to be made of both anatase and rutile TiO2, with groove–shaped structure and cracks on the surface of the TiO2 film. The intrinsic biocompatibility of the chemically modified porous Ti surfaces was assessed in vitro. In our cell culture tests, stem cells were found to attach and proliferate better on the chemically treated Ti surfaces compared to the control untreated Ti surfaces.


Author(s):  
Haiming Zhou ◽  
Jing Zhang ◽  
Xiaoqing Chen ◽  
Shili Guo ◽  
Huimei Lin ◽  
...  

Background and Objective: Beauvericin (BEA), a cyclic hexadepsipeptide mycotoxin, is a potent inhibitor of the acyl-CoA: cholesterol acyltransferase enzyme 1 (ACAT1) which involved in multiple tumor-correlated pathways. However, the binding mechanisms between BEA and ACAT1 were not elucidated. Methods: BEA was purified from a mangrove entophytic Fusarium sp. KL11. Single-crystal X-ray diffraction was used to determine the structure of BEA. Wound healing assays of BEA against KB cell line and MDA-MB-231 cell line were evaluated. Inhibitory potency of BEA against ACAT1 was determined by ELISA assays. Molecular docking was carried out to illuminate the bonding mechanism between BEA and ACAT1. Results: The structure of BEA was confirmed by X-ray diffraction, indicating a monoclinic crystal system with P21 space group (α = 90°, β = 92.2216(9)o, γ= 90o). BEA displayed migration-inhibitory activities against KB cells and MDA-MB-231 cells in vitro. ELISA assays revealed the protein expression level of ACAT1 in KB cells was significantly decreased after BEA treatment (P <0.05). Molecular docking demonstrated that BEA formed hydrogen bond with His425 and pi-pi staking with Tyr429 in ACAT1. Conclusions: BEA sufficiently inhibited the proliferation and migration of KB cells and MDA-MB-231 cells by downregulating ACAT1 expression. In addition, BEA potentially possessed a strong binding affinity with ACAT1. BEA may serve as a potential lead compound for the development of a new ACAT1-targeted anticancer drug.


1986 ◽  
Vol 250 (2) ◽  
pp. F302-F307 ◽  
Author(s):  
J. M. Burnell ◽  
C. Liu ◽  
A. G. Miller ◽  
E. Teubner

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.


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