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	The potential of plastic biodegradation by basidial fungi and actinobacteria (review)
	I.G. Shirokikh, А.А. Shirokikh
	Section: Theoretical problems of ecology
	With the ever-increasing production and consumption of plastics, inadequate management of plastic waste and its improper disposal pose a significant threat to the environment, affecting all forms of life, natural ecosystems and economies worldwide. In the face of this threat the search for alternative environmentally friendly solutions such as biodegradation instead of traditional recycling is of paramount importance. Currently knowledge about the mechanisms and effectiveness of plastics biodegradation is focused mainly on such groups of microorganisms as Gram-negative bacteria and fungi ascomycetes. The aim of this review is to highlight the ideas available in the literature about the potential decomposition of the most common plastic waste (polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate and polyurethane) as a result of biotic processes. Basidial fungi and actinobacteria have not yet found practical application in the technologies of processing and utilization of synthetic plastics. We discuss the ability of specific representatives of the two above taxonomic groups to decompose various synthetic polymers. The unique strategies of basidial fungi such as a powerful enzymatic system, the ability to absorb and produce natural biosurfactants – hydrophobins, allowed fungi to use plastics as a source of carbon and energy are considered. The possible contribution of mainly thermophilic actinobacteria of the genera Thermobifida, Thermoactinomyces, Thermomonospora, Saccharomonospora, Actinomadura, Microbispora and Streptomyces in improving the plastic waste disposal in order to create effective and sustainable plastic management practices has been characterized.
	Keywords: pollution, plastic waste, biodegradation, microorganisms, enzymatic systems
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-006-021
	Views: 3
	Obtaining heterological rhamnolipid producers for industrial production of highly-effective biosurfactant
	M.N. Baramzin, S.G. Litvinets, E.A. Martinson
	Section: Remediation and rehabilitation
	Rhamnolipids are promising microbial glycolipid biosurfactants that can be used as preparations for soil bioremediation in oil pollution. The expression of the rhamnolipid biosynthesis gene cluster in the main producer, Pseudomonas aeruginosa, is regulated by quorum sensing signals (QS). Complex biosynthesis regulation does not allow achieving high product yields. The production of heterologous rhamnolipid producers is a promising way to overcome the complex QS-dependent regulation of rhamnolipid biosynthesis, and also avoids the use of opportunistic Pseudomonas aeruginosa for the industrial production of rhamnolipids. Heterologous Escherichia coli BLWT-based producers with a transformant E14 productivity of 3.40±0.96 g/L were obtained on the basis of the plasmid vector pAl2–T with a construct from the native promoter and rhlAB genes, and Pseudomonas viridiflava AlC1223-based ones with the productivity of transformants P5, P6, P8 332.00±0.10, 200.00±0.10 and 180.00±0.10 g/L, respectively. The presence of rhlAB genes in the expression vector allows the obtaining monorhamnolipids for further use as an agent for the solubilization of soil hydrophobic pollutant (e. g. petroleum products), which will intensify bioremediation processes.
	Keywords: rhamnolipids, heterologous expression, pseudomonads, biosurfactants, oil degraders, glycolipids
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-135-142
	Views: 3
	Biological contamination of soils by livestock by-products
	N.V. Syrchina, L.V. Pilip, E.P. Kolevatykh, T.Ya. Ashikhmina
	Section: Ecology and climate change
	By-products of animal husbandry (BPAH) such as manure, manure effluents (ME) are widely used as organic fertilizers. The main disadvantage of the appropriate fertilizers is the high content of microorganisms (MO) untypical to uncontaminated natural environments, including pathogenic ones. Currently used natural methods of BPAH neutralization can significantly reduce the risks of transferring pathogenic and opportunistic MO into fertilized soil, but do not completely exclude them. The study examined the effects of long-term (more than 7 years) introduction of a neutralized liquid fraction (LF) of pork ME and cattle ME on the chemical composition and sanitary and hygienic condition of the soil of arable fields and wooded areas located at 500 m from the boundaries of the fields. Prolonged application of LF led to an increase in the content of organic matter, mobile phosphorus, potassium and sulfur, an increase in the amount of absorbed bases, a decrease in metabolic acidity in arable land compared with adjacent forest areas. However the sanitary condition of both arable land and adjacent territories deteriorated significantly. A significant increase in the total microbial number (TMN) was revealed in all soil samples in comparison to the normative indicators. Particularly high values of TMN were found in soil fertilized with cattle manure. The corresponding soil was characterized by the highest content of organic matter and neutral reactions of the environment, which provided favorable conditions for the active development of saprophytic microbiota. Fresh faecal contamination was detected in all selected soil samples. Soils are characterized as highly polluted. According to the indicators of the index Escherichia coli, Enterococcus and Clostridium perfringens, the soils of all studied sites are moderately dangerous. Higher values of the corresponding indices were found in arable land fertilized by the LF of pork farms and in the territories adjacent to arable land. In the course of sanitary and bacteriological studies, eggs of helminthes were not found in the soil.
	Keywords: by-products of animal husbandry, organic fertilizers, soil sanitation, biological pollution
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-201-210
	Views: 1
	Some patterns of the accumulation of trace elements in the leaves of linden (Tilia cordata Mill.) and birch (Betula alba L.)
	A.V. Gorbunov, D.B. Petrenko, A.A. Dronova
	Section: Chemistry of natural environments and objects
	The purpose of the work: to study the patterns of background accumulation of trace elements during the spring-summer-autumn season in the vegetative organs (leaves) of the heart-shaped linden (Tilia cordata Mill.) and white birch (Betula alba L.). Samples were taken on the territory of the Main Botanical Garden of the Russian Academy of Sciences during one season of 2018 from the same tree with an interval of 10–12 days, starting from the opening of the bud (end of April) right up to the time of leaf fall. Soil samples were also taken from birch and linden growing areas. The samples were analyzed in the laboratory of Chemical analytical methods of the GIN RAS using X-ray fluorescence analysis (XRF), instrumental neutron activation analysis (INАA) and atomic absorption spectrometry of cold vapor (AA). The concentration of trace elements in the selected soil samples corresponds to the concept of “background” contents. Two types of trace elements’ distribution in linden and birch leaves during the season have been revealed. The first type is a uniform accumulation of trace elements with a maximum at the end of the season (Na, Ca, Cr, Fe, Co, Br, Sb, La). The second type of distribution is characterized by a maximum concentration of trace elements in the middle of the season with a decrease in concentration by the time of leaf fall (K, As, Zn, Cd, Pb). It should be noted that the range of changes in the concentration of trace elements during the season in both cases can reach 10–15 times. We recommend to take samples of vegetation (leaves) as soon as possible in the middle of the summer season, and to use samples taken at the same time in the same area as “background”.
	Keywords: trace elements, accumulation, vegetative organs, higher plants
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-063-071
	Views: 2
	Study of patterns of changes in salt compositiondrill cuttings in the process of their disposal
	E.V. Gaevaya, L.V. Rudakova
	Section: Remediation and rehabilitation
	Drill cuttings in their natural state have viscous-plastic properties; in a dry state they are cohesive and hard. This is due to the content of sodium ions in the absorbing complex. Features of the physical and mechanical properties of drill cuttings indicate its ability to absorb and retain dissolved salts. When gypsum is added to drill cuttings in different percentages of the waste volume, the concentration of chloride ion changes in all samples, and chloride-sulfate salinization is observed. The content of sulfate ion increases with a minimum volume fraction of gypsum application. The addition of gypsum in a volume fraction of 15 and 20% affects the reduction of phosphate and carbonate ions. A change in electrical conductivity indicates an increase in the concentration of water-soluble salts in the water extract, which is confirmed by a direct high correlation. When adding gypsum from 7–20% volume fractions, a significant reduction in the dense residue occurs. The use of gypsum increases the filtration capacity of drill cuttings. The use of gypsum makes it possible to lighten the granulometric composition of drill cuttings due to the active coagulation of colloids. As a result of the removal of water-soluble salts, optimal water-physical properties of drill cuttings are created, structuring and filtration properties of drill cuttings are increased. A mathematical model for predicting the dissolution of salts in drill cuttings allows taking into account uncontrollable factors (density, particle size distribution, filtration coefficient, content of water-soluble salts).
	Keywords: drill cuttings, salt composition, dissolution rate coefficient
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-125-134
	Views: 1
	The effect of radionuclide-contaminated environment on children’s heart rate
	O.V. Kalabin, F.B. Litvin, T.M. Bruk, I.V. Bykova, E.V. Udovenko
	Section: Social ecology
	The main aim was to study the characteristics of heart rate variability in 8- and 10-year boys and girls that permanently reside in areas with an increased level of radioactive contamination. The body functions are formed by close interaction of the body and the environment. The adaptive responses of the developing organism are improved at each ontogenetic stage as its contact with the environment become more complex. We found that features of heart rate regulation depend on the area of residence. The contribution of the autonomous circuit of heart rate regulation is increased for 8- and 10-year-old girls from radio-ecologically safe areas (RESA). Based on the principle of functional antagonism this leads to a weakening of the central circuit of regulation. The shift gradient of indicators is higher for 8-year-old girls from radio-ecologically unfavorable areas (REUA) compared to 10-year-old girls. This reflects the greater sensitivity of their organism to adverse factors. The dominance of the autonomous circuit of regulation was marked for 8- and 10-year-old boys from the RESA. In contrast an imbalance in the operation of regulatory mechanisms with an increase in the central regulatory circuit was found for boys from the REUA. High centralization of cardiac control indicates that adaptation mechanisms are in a state of pronounced tension. The increase in the shift gradient for boys from REUA falls at the age of 10 years. The results of the study revealed gender differences in the regulation of heart rhythm. The obtained data is important diagnostic aspects of morphofunctional maturation of the organism for subsequent ontogenetic stages depending on environmental living conditions.
	Keywords: age, sex, radiation, heart rate variability, radio-ecological living conditions
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-219-225
	Views: 1
	Photosynthetic activity of coniferous undergrowth after industrial felling
	V.V. Tuzhilkina
	Section: Methodology and research methods. Models and forecasts
	The functioning of coniferous undergrowth of preliminary and subsequent generations after industrial felling was considered in the middle taiga subzone of the Komi Republic. Using spectrophotometric and gasometric methods we analyzed the pigment activity, photosynthetic, and respiratory abilities of the assimilation apparatus of pine (Pinus sylvestris L.) and spruce (Picea obovata Ledeb.) undergrowth at the 3- and 10-year old clearings. The pigment apparatus functional rearrangement of the preliminary generation spruce undergrowth at clearings was found. Needles adapt to environmental conditions at the pigment system level by changing the content and ratio of chlorophylls and carotenoids. Changes in plastids in the spruce undergrowth at the 3-year clearings occurred due to a decrease in chlorophyll and carotenoid concentrations, and at the 10-year clearings due to activation of pigment synthesis which affects the carbon dioxide absorption in chloroplasts. The assimilation apparatus of spruce undergrowth at clearing absorbs CO2 by 1.4 and 1.8 time more actively than that under the forest canopy. The photosynthetic and respiratory abilities of spruce needles at clearings do not differ. This indicates a stable level of important vital processes for the studied undergrowth at clearings during ten years after felling. Pine and spruce undergrowth needles are able to absorb CO2 at a fairly high rate up to 5.73 and 2.7 μmol CO2/(m2 · s) respectively. This rate contributes to the accumulation of assimilates in pine needles and their use for growth which logically increases the productivity of undergrowth at clearings. In general, the functional organization of spruce and pine undergrowth assimilating organs ensures their growth and favors the successful restoration of conifers at clearings in the middle taiga subzone of the European North-East.
	Keywords: spruce, pine, undergrowth, needles, industrial felling, clearing, pigments, photosynthesis, respiration
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-022-028
	Views: 5
	Diversity of soil diatom communities of Frolikhinsky State Nature Reserve
	A.I. Fazlutdinova, N.V. Sukhanova, L.A. Gaysina
	Section: Population ecology
	The species composition of soil diatoms in Frolikhinsky State Nature Reserve was studied. Flora of diatoms algae was represented with 128 taxa of 4 classes, 12 orders, 23 families and 49 genera. The greatest diversity of species was found on the bank of the Bireya River (77 species), and the lowest – on the Barguzinsky ridge pass (3 species). In most species and intraspecific taxa of diatoms (97%) found in the reserve, the occurrence rate varied from 10 to 40%. An occurrence rate above 40% was noted only in four taxa that were identified as leading: Pinnularia borealis (80%), Adlafia bryophila (50%), Gomphonema parvulum (50%) and Planothidium lanceolatum (50%). The complex of dominant species was diverse and included representatives of 15 families. 36 species and intraspecific taxa were classified as dominants, 20 taxa were classified as subdominants. The complex of associated species included 6 taxa, 67 taxa were found singly and occasionally. Pinnularia borealis Ehrenberg had the highest occurrence at all sites. The families Fragilariaceae, Achnanthidiaceae, Naviculaceae, Ahnanthaceae, Gomphonemataceae, Cymbellaceae, Cocconeidaceae, Eunotiaceae, Pinnulariaceae, Bacillariaceae, Sellaphoraceae were characterized by high species diversity. Comparison of diatoms complexes (DC) in different plots of the reserve revealed similarities and differences of floristic diversity and taxonomic structure. The main reasons of taxonomic heterogeneity of DC in different areas are the conditions defined by their location within the natural reserve. The largest number of species was found on the shores of water bodies characterized by a high degree of moisture. The least abundant and diverse diatoms were represented in shaded and insufficiently moist areas of coniferous forests with abundant coniferous litter and acidic soils.
	Keywords: habitat, diatoms complexes (DC), species composition, Lake Baikal, Pinnularia borealis, Adlafia bryophila, Gomphonema parvulum, Planothidium lanceolatum
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-175-184
	Views: 1
	Antibiotic ciprofloxacin in water and soil media: reaction of microalgae
	A.D. Batakov1, A.P. Kiryushina, D.N. Matorin, V.A. Terekhova
	Section: Ecotoxicology
	Pharmaceuticals and antibiotics in the environment are of increasing concern due to the impact on representatives of all links in the food chain of natural ecosystems. The effect of the widespread antibiotic ciprofloxacin (Cip) on the green protococcal microalgae Scenedesmus quadricauda and Chlorella vulgaris in water and aqueous soil extracts (artificial standard soil, technosoil, soddy-podzolic soil) was studied in model experiments. Fluorescent parameters were assessed by two different methods (Fluorat 02-5M and Water-PAM devices). The phenomenon of hormesis was observed at low antibiotic concentrations of 5 and 10 mg/L. A decrease in the photosynthetic activity of algae was recorded at an increase of Cip content from 20 to 50 mg/L. A comparison was made of the median (average effective) concentration of the EC50 antibiotic, which suppresses the fluorescent characteristics of microalgae by 50% on 3 days of exposure in different media. The decrease in the toxicity of the studied dose of Cip (300 mg/L) in a number of studied objects can be represented as follows: water > technosoil > artificial standard soil > soddy-podzolic soil. It reflects the percentage of inhibition of the test function relative to the control (samples without antibiotic) by 91.5, 80.0, 62.5, and 60.0% respectively. In the soil matrix, the inhibitory effect of the antibiotic is less pronounced (by 10–30%), probably due to the protective properties of humic substances that adsorb the antibiotic or its metabolites.
	Keywords: algotesting, ecotoxicity, antibiotic ciprofloxacin, water, soil, humic substances
	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-143-150
	Views: 1
	Functional characteristics of Нeracleum sosnowskyi Manden. terminal buds during preparation for overwintering
	S.P. Maslova, O.V. Dymova, R.V. Malyshev, I.V. Dalke
	Section: Population ecology
	Based on the study of the physiological and biochemical characteristics of Heracleum sosnowskyi buds we identified functional adaptations during the preparation of plants for overwintering. The freezing point of water in the buds tissues was –12 оC in October, while maintaining high water content (more than 80%). Buds has a relatively high efficiency of respiration at low positive temperatures (2–5 оC), which favors morphogenesis processes in the shoot vegetative cone in autumn. During the preparation for overwintering the buds accumulated osmoregulators – soluble sugars, free amino acids, including proline. A relatively high level of cytokinin growth hormones was found in the buds tissues. This contributes to morphogenesis processes and increases plant cold tolerance. We found that in December the abscisic acid (a growth inhibitor and resting hormone) content increases and the level of cytokinins decrease. Heracleum sosnowskyi formed buds differing in the photosynthetic pigments content. Buds with green scale leaves accumulated the greatest amount of chlorophylls and carotenoids, while those with red-brown and yellow ones accumulated the least. The carotenoids accumulation in the green buds tissues protects the formed photosynthetic apparatus at low positive temperatures in autumn. The results on the functional state of H. sosnowskyi terminal buds in natural populations indicate the absence of deep dormancy in plants, and morphogenesis processes in meristems tissues are limited by winter temperatures.
	Keywords: Heracleum sosnowskyi, buds, respiration, non-structural carbohydrates, amino acids, photosynthetic pigments, phytohormones, overwintering
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	Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-185-192
	Views: 1

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