Refinement of the crystal structures of biomimetic weddellites produced by microscopic fungus Aspergillus niger

Two new complexes of nickel (II) with 4-amino-3, 5-bis(pyridyl)-1, 2, 4-triazole (abpt) and iron (II) with 2-(3-phenyl-1H-pyrazole-5-yl) pyridine (phpzpy) have been synthesized and characterized by elemental analysis and IR spectroscopy. The crystal structures of the complexes have been determined by single crystal X-ray diffraction techniques. In the nickel and iron complexes, the ligands are coordinated through nitrogen atoms in bidentate manner. The ligands and their respective complexes have been tested for their antifungal activity against Aspergillus niger, Aspergillus flavus, and Candida albicans. From the study, the complexes showed enhanced activities against the tested organisms compared to the ligands.

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Influence Of Fine-Grained Montmorillonite On Microfungal Pellets Growth In Aqueous Suspensions

Nova Biotechnologica et Chimica ◽

10.1515/nbec-2015-0012 ◽

2015 ◽

Vol 14 (1) ◽

pp. 38-44

Author(s):

Karol Jesenák ◽

Alexandra Šimonovičová ◽

Slavomír Čerňanský

Keyword(s):

Aspergillus Niger ◽

Clay Mineral ◽

Microscopic Analysis ◽

Significant Inhibition ◽

Final Size ◽

Microscopic Fungus ◽

Simultaneous Application ◽

Inhibition Effect ◽

Fine Grained ◽

Mineral Particles

Abstract The paper presents an inhibition effect of clay mineral – montmorillonite – on the growth of microscopic filamentous fungus Aspergillus niger in the aqueous solution. The significant reduction in growth of the final size of spherical fungal pellets as well as total amount of produced microbial biomass was found out. Within the observed range of additions of clay mineral of 1, 5, 10, 15 and 20 g in the total volume of the 80 ml suspension, this size was in indirect relation to the weight of montmorillonite. However, the most significant inhibition effect was observed at the lowest concentration of the sorbent (1 g). Microscopic analysis of pellets referred to the presence of mineral particles in their pore structure and the distribution of particles in the spatial structure of fungal hyphae was variable. The experiment clearly demonstrated an inhibition effect of montmorillonite. This inhibition could be answered by the experiments focused on the detection of the influence of size and shape of inorganic sorption particles together with the influence of the physicochemical properties of its surface. It could be stated that the simultaneous application of the microscopic fungus Aspergillus niger and the clay mineral montmorillonite for decontamination of waste waters should be disadvantage due to their interaction if compared with the decontamination based on bioaccumulation and sorption separately.

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Simultaneous lithium bioleaching and bioaccumulation from lepidolite using microscopic fungus Aspergillus niger

Nova Biotechnologica et Chimica ◽

10.36547/nbc.v19i2.771 ◽

2020 ◽

Vol 19 (2) ◽

pp. 175-182

Author(s):

Renáta Marcinčáková ◽

Alena Luptáková ◽

Marek Vojtko ◽

Martin Fujda ◽

Jana Sedláková-Kaduková

Keyword(s):

Citric Acid ◽

Aspergillus Niger ◽

Filamentous Fungus ◽

Glucose Concentration ◽

Fungal Biomass ◽

Hard Rock ◽

Silicate Phase ◽

Microscopic Fungus ◽

Sem Analyses

The leaching of lithium from lepidolite using the filamentous fungus Aspergilluss niger was examined. Two mechanisms were suggested – biochemical using citric acid as the main bioleaching agent and biomechanical through hyphae penetration confirmed by XRD and SEM analyses. The bioleaching processes were conducted at various glucose concentrations (5 – 20 g.L-1). The higher glucose concentration was, the higher Li bioleaching was observed. Li accumulation by fungal biomass played an important role in Li solubilisation from lepidolite. Totally, 11.5 mg of lithium were recovered from 1 kg of lepidolite by combination of bioleaching and bioaccumulation processes. As a result of bioleaching, the formation of new silicate phase of SiO2 was detected. According to the results, fungal bioleaching of Li from lepidolite can be a perspective way of Li recovery from hard-rock ores.

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Iron Oxalate Humboldtine Crystallization by Fungus Aspergillus niger

Crystals ◽

10.3390/cryst11121591 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1591

Author(s):

Marina S. Zelenskaya ◽

Alina R. Izatulina ◽

Olga V. Frank-Kamenetskaya ◽

Dmitry Y. Vlasov

Keyword(s):

Aspergillus Niger ◽

Solid Substrate ◽

Oxidation States ◽

Calcium Oxalate Crystals ◽

X Ray Diffraction ◽

Microscopic Fungus ◽

X Ray ◽

Iron Oxalate ◽

Iron Bearing

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.

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High-resolution dimeric crystal structures of wild-type and mutant Aspergillus niger glucose oxidase

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273319094233 ◽

2019 ◽

Vol 75 (a2) ◽

pp. e133-e133

Author(s):

Jelena Pavlovic ◽

Andrea Szalayová ◽

Julius Kostan ◽

Kristina Djinovic-Carugo ◽

Vladena Bauerova ◽

...

Keyword(s):

High Resolution ◽

Aspergillus Niger ◽

Glucose Oxidase ◽

Crystal Structures ◽

Wild Type

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Pollutant Identification by Selected Area Electron Diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052675 ◽

1974 ◽

Vol 32 ◽

pp. 532-533

Author(s):

R. E. Ferrell ◽

G. G. Paulson ◽

C. W. Walker

Keyword(s):

Thermal Treatment ◽

Electron Diffraction ◽

Sample Preparation ◽

Crystal Structures ◽

Water Samples ◽

Environmental Samples ◽

Short Review ◽

Selected Area Electron Diffraction ◽

Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

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The Imaging of Crystal Structures and Crystal Defects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069995 ◽

1978 ◽

Vol 36 (3) ◽

pp. 207-217

Author(s):

J.M. Cowley

Keyword(s):

Electron Microscope ◽

Crystal Structures ◽

Phase Contrast ◽

Crystal Defects ◽

Atom Density ◽

Lack Of Information ◽

Spatial Frequencies

The problem of "understandinq" electron microscope imaqes becomes more acute as the resolution is improved. The naive interpretation of an imaqe as representinq the projection of an atom density becomes less and less appropriate. We are increasinqly forced to face the complexities of coherent imaqinq of what are essentially phase objects. Most electron microscopists are now aware that, for very thin weakly scatterinq objects such as thin unstained bioloqical specimens, hiqh resolution imaqes are best obtained near the optimum defocus, as prescribed by Scherzer, where the phase contrast imaqe qives a qood representation of the projected potential, apart from a lack of information on the lower spatial frequencies. But phase contrast imaqinq is never simple except in idealized limitinq cases.

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Transmission electron microscope studies in special ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108489 ◽

1978 ◽

Vol 36 (1) ◽

pp. 268-269

Author(s):

A. Zangvil ◽

L.J. Gauckler ◽

G. Schneider ◽

M. Rühle

Keyword(s):

Phase Diagrams ◽

Crystal Structures ◽

Thin Foil ◽

Limited Extent ◽

Complex Materials ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Electron Microscopes ◽

Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

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