The influence of anthropogenic pollution, particularly with polycyclic aromatic hydrocarbons (PAHs) on soil toxicity and spread of antibiotic resistance genes (ARGs) is extremely important nowadays. ...We studied 20 soil samples from a technogenically polluted site, municipal solid wastes (MSW) landfills, and rural settlements in the southwestern part of the Rostov Region of Russia. A close correlation was established between the results of biosensor testing for integral toxicity, the content of genes for the biodegradation of hydrocarbons, and the concentration of PAHs in soils. The relation between the quantitative content of ARGs and the qualitative and quantitative composition of PAHs has not been registered. Soils subjected to different types of the anthropogenic pressure differed in PAHs composition. The technogenic soils are the most polluted ones. These soils are enriched with 5 ring PAHs and carry the maximum variety of assayed ARGs, despite the fact that they do not receive household or medical waste.
•At biotesting soils contaminated with industrial PAHs are more toxic than landfills.•Technogenically polluted soils are enriched with 5 ringPAHs compared to landfills.•Technogenically polluted soils contain more diverse ARGs.
•The high content of pollutants negatively affects bacterial biodiversity.•The structure of soil microbiome depends on the pollutant type.•Pollutants have diverse effects on different bacterial taxa.
...Metagenomic studies of soil microbocenoses are extremely relevant nowadays. The study of pollution impact on soil microbiomes is of particular interest. The structure of microbial communities in soils with different levels of pollution by polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) was studied. High bacterial biodiversity was found in all the studied soil samples, but its lowest values are found in soil samples taken on the territory of technogenically polluted Lake Atamanskoye. Assessment of soil pollution showed the highest content of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) for the soils Lake Atamanskoye. The high content of pollutants negatively affects the abundance of representatives of the phyla Actinobacteria, Planctomycetes, Verrucomicrobia, and Nitrospirae. Such phyla as Proteobacteria, Candidate Divisions TM7, OD1, WPS-2, Chlamydiae, Cyanobacteria are characterized by positive direct correlation with the content of pollutants, especially with PAHs. A cooperative effect of decrease in the number of Actinobacteria and Proteobacteria with an increase in Armatimonadetes probably corresponds to PTEs contamination. The proportion of Candidate Division OD1, Chlamydiae, Cyanobacteria, and Candidate Division WPS-2 was increased in the soil microbiome under the influence of severe combined pollution. Pollutants negatively affect the abundance of dominant unclassified_o__Gaiellales and unclassified_o__WD2101 genera. Iamia, Salinibacterium, Arthrobacter, Kaistobacter, Thiobacillus genera are characterized by a low abundance, but they are presumably the most resistant to soil pollution. It was revealed that the level of soil pollution largely determines the composition and diversity of bacterial communities in the soils of the studied territories. Operating taxonomic units have been established that have prognostic value for assessing the state, level of soil pollution, and their biological safety.
This paper discusses results from mineralogic, petrographic, and petrochemical studies of diamond-bearing volcanic rocks that were erupted by the 2012–2013 Tolbachik Fissure Eruption. This is the ...first time that the reader can find an integrated description of crystal-morphologic, spectroscopic, thermal, and isotopic-geochemical properties of diamonds extracted from fresh basaltoids. We examined the micromineralizations that are accessory to the diamonds and provide a rationale for why the type (previously unknown) of non-kimberlite diamond findings should exist in nature.
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The crystal growth theories based on atomic phenomena are eventually oriented to the description of a macroscopic phenomenon. The adequacy of theoretical concepts can be justified using the Bohr’s ...correspondence principle. The time used in the equations of nonequilibrium thermodynamics is in complete correspondence with the Bohr’s principle. It is shown that the equation for a dynamic stationary form of a growing crystal, obtained within nonequilibrium thermodynamics at a decrease in the growth rates of the crystal faces, is transformed into the Wulff equation, which is used to describe the equilibrium crystal form. A continuous transition of the morphological spectrum of a dynamic stationary form of a growing crystal to the spectrum of an equilibrium crystal form within the Gibbs approximation of fluctuations is also demonstrated. However, the variable of time introduced into classical dislocation crystal-growth theories based on equilibrium statistical concepts hinders the application of the correspondence principle.
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An expression for the generalized capillary constant of an equilibrium crystal, taking into account the influence of the gravitational field, is obtained. The height limit for an equilibrium single ...crystal is determined. It is shown that the equilibrium form of a macrocrystal, oriented randomly in the gravity field, cannot be described by a convex polyhedron. Thermodynamic calculations of the gravity effect on the form of a stationary growing crystal in stirred and immobile homogeneous solutions have been performed. It is shown that gravity barely affects the stationary form of a growing crystal in a thoroughly stirred solution at low temperature; however, growth in an immobile homogeneous solution leads to a significant relative decrease in the crystal height.
The limiting free form of a crystal growing in an open system in kinetic and diffusion modes of stationary process has been geometrically described based on the limiting principle of nonequilibrium ...thermodynamics (entropy-production minimum). An analog for an equilibrium closed thermodynamic system is the Wulff theorem. However, the equilibrium form of a mineral crystal can barely be found in nature, whereas the stationary form is abundant and (taking into account the natural variations in the growth rates of faces) is presented by a class of full-face morphological types of polyhedral crystals of simple habit crystallographic form.
The relationship of morphological spectra (sets of data on the morphological types of real polyhedral crystals and their probabilities under current physicochemical conditions of natural process) is ...shown for different simple crystallographic forms. The methods for constructing generalized and open polyhedra, reducing the multiplicity of symmetry-equivalent crystal faces, are proposed to describe the dissymmetry of medium (as the most general property of the crystallization process). A method for calculating the dissymmetry factor of a natural process is described based on the spectra of these polyhedra.
The specific features of application of a low-energy atomic-force microscope (AFM) for studying the dynamic process of face growth in terms of the fluctuation model of crystal growth are discussed. ...It is shown that the probe interaction with an area of growing crystal surface on the time scale characteristic of a sequence of free energy fluctuations is a limiting factor for constructing an image of growing face surface. Agreement between the phenomenological and quantum (according to the uncertainty relation) descriptions of the effect of limiting magnification for a growing crystal face in an AFM is demonstrated. Specific features of detecting a growth stage on a crystal face using a transmission/scanning high-resolution electron microscope in a gas medium are also discussed. The effect of ultimate magnification when observing crystal growth in an АFМ is a basis for discussing the concept of the transient state of matter in the topochemical reaction of crystal growth and the phenomenon of building particle.
A theory of nonequilibrium stationary crystal growth is presented, which is based on the equilibrium theory of monolayer adsorption of impurities and thermodynamic fluctuations of free energy. Two ...limiting transitions between the events determining the face growth have been implemented using methods of the theory of random processes; a unified theoretical description of crystal growth in the range of scales from several tens of nanometers to more than ten centimeters is developed based on these transitions. The approach to the crystal growth as a set of thermodynamic fluctuations makes it possible to avoid detailed consideration of atomic scale phenomena accompanying the growth. The developed theory allows one to describe the dynamic nonequilibrium shape of a macroscopic polyhedral crystal and perform the final transition to the equilibrium crystal shape. An expression is given for the stationary shape of a crystal growing from a solution, in which the surface density of entropy production for each crystal face is isolated as the most important dynamic function of the stationary state, which depends on the indicator of deviation from equilibrium—supersaturation—and combines the concentration, thermal, and gravitational phenomena occurring in the heterogeneous thermodynamic system: crystal–adjacent solution.
The statistical regularities of collective crystal growth under isotropic/anisotropic conditions are described based on the adsorption-fluctuation dislocation growth model. A version of realization ...of the Curie symmetry principle for an open stationary nonequilibrium system, described by random processes, is presented. The form of manifestation of the Curie principle is shown to depend not only on the physical conditions of the crystallization process but also on the structure of transitions between morphotypes (a Markov chain).
