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  • The physiological state of the Fucus vesiculosus L. of the Barents Sea in a prolonged air condition

    Ryzhik, I. V.; Makarov, M. V. (2018)
    The increase in anthropogenic pressure on ecosystems necessitated the implementation of measures aimed at purifying the environment and restoring disturbed biocoenoses. To remediate the marine environment from heavy metals, radionuclides, oil products, it has been proposed to use plantations-biofilters, the biological components of which are seaweeds. Fucoids, in particular Fucus vesiculosus, have been identified as the most suitable objects as they have a high sorption activity to heavy metals, radionuclides, are able to include petroleum hydrocarbons in own metabolism. By the standard methods of plant physiological research (determination of photosynthetic activity, content of photosynthetic pigments, relative water content) the ability of F. vesiculosus to withstand prolonged exposure to air has been determined. In the experiment, the algae were placed on the netting, twisted into a roll wrapped with a tarp (to prevent drying plants) and set in different experimental conditions (in constant (8 ?C) and variable (7–19 ?C) temperatures). Algae retained the photosynthetic capacity for 30 days, but after 20 days there was a decrease in this process compared to control. After the experiment, algae recovered the level of photosynthetic capacity for one day. The total content of chlorophylls and the ratio of Chl A / Chl C during the experiment did not change, which also indicates the sustainability of the photosynthetic apparatus of F. vesiculosus. It has been shown that F. vesiculosus is able to maintain physiological activity within 30 days if it is under conditions that ensure moisture retention in the thalli is not less than 55 %. This ability expands the potential of using F. vesiculosus as an object of sanitary aquaculture: it is possible to pre-build modules of plantation-biofilter and their long transportation.
  • History and status of sturgeon stock (Acipenseridae) in the Caspian pool

    Vlasenko, A. D.; Bulgakova, T.I.; Lepilina, I. N.; Konopleva, I. V.; Safaraliev, I. A. (2020)
    Analysis of materials from long-term studies characterizing the current state of sturgeon stocks in the Volga-Caspian fisheries basin, and the dynamics of commercial catches of beluga, sturgeon and stellate sturgeon in the XX – XXI centuries indicates that the Northern Caspian occupies the leading value in catch volumes, where more than 70 % of sturgeon fish are annually harvested. In the first half of the twentieth century sturgeon stocks were determined by the scale of natural reproduction in rivers and fishing volumes; in the second half, natural and anthropogenic factors began to intensively influence the formation of sturgeon stocks. The development of hydraulic construction on rivers, an increase in the withdrawal of freshwater runoff, a decrease in sea level to –29.0 mBS, pollution by industrial and agricultural runoff have necessitated the development of a set of measures for the reproduction, conservation and rational use of the Caspian’s aquatic biological resources. As a result of the studies, the response of the sturgeons to the changed conditions of reproduction has been determined in order to restore and increase their commercial stocks; high ecological adaptability of sturgeons to various living conditions within their range, their exceptional plasticity and pronounced intraspecific differentiation have been established. These indicators point to the possibility of creating conditions that meet the requirements for water quality for the life of sturgeons during migration and reproduction. In the course of the analysis of the obtained data, the influence of regulation of the Volga River flow on the efficiency of natural reproduction of sturgeons has been evaluated; the role of industrial sturgeon breeding in sturgeon stock formation has been shown; the abundance of juveniles in the North Caspian and adult individuals on feeding pastures of the sea has been estimated; trends in the number of sturgeon producers migrating in the Volga to spawning sites have been identified; the prospects for the restoration and rational use of sturgeons in the Volga-Caspian basin have been determined.
  • Some information on biology of three-spined stickleback Gasterosteus aculeatus Linnaeus, 1758 in the Barents Sea coastal region (East Murman)

    Garmash, M. V.; Zhuravleva, N. G. (2020)
    Three-spined stickleback is one of the widespread fish species of East Murman. It is found in 13 catchment areas of the Barents Sea coast in the eastern part of the Murmansk region, including major rivers, shallow river basins and inter-basin spaces. Stickleback is found in such lakes as Enozero, Pervoe Titovskoe, Opasovskoe, Dolgoe, etc, and in the rivers Yokanga, Varzina, Kharlovka, Voronia, Teriberka, etc. There is no detailed biological description of stickleback in this area, and the information available only mentions its presence in water bodies and occurrence in the stomachs of predators. The present paper provides data on three-spined stickleback caught in the coastal region of the Barents Sea at a depth of 120–123 m. The marine form of stickleback spends entire life cycle in the sea. In the Barents Sea, stickleback has a pelagic way of life, going quite far from the shore. According to the published data, its habitat depth in the Barents Sea is 50–450 m, with an average of 270 m, where temperature varies from 0 to 4 °C, with salinity 33–35 ‰. It has been found out that stickleback is represented by two morphotypes – trachurus with a keel (98 %) and semiarmatus (2 %) with a keel. The study has revealed different number of lateral plates and the nature of their distribution on the body of stickleback. In the study area, individuals of different size groups could be found. On average their body length ranges from 51 to 60 mm with a maximum length of 81 mm; the weight changes from 0.79 to 1.39 g. The authors have observed positive allometry of the dependence of mass on body length. Proportion of empty stomachs is almost 100 % with the fat content 1–2 points. The gonads of males and females caught in August 2015 were in after spawning condition. Females comprise the majority of the population (65 %). Infestation of stickleback with helminths is insignificant. Larvae of Anisakis simplex nematode have been observed most frequently during the examination of internal organs and body cavity.
  • Comparative lithological characteristics of modern sediments of the Kara and Pechora Seas

    Chikirev, I. V.; Uliantsev, A.S.; Nikiforov, S.L.; Sorokhtin, N. O.; Dmitrevskiy, N. N.; Libina, N. V.; Kovalev, G. A. (2020)
    Global climate warming and increased anthropogenic pressure on the Arctic shelf contribute to the development of thermoabrasive processes along the coast of the western sector of the Russian Arctic.Comprehensive geophysical, hydroacoustic, geological-geomorphological, and hydrophysical scientific studies were carried out within the Kara and Pechora Seas in June – July 2019, during the 41st cruise of the R/V Akademik Nikolai Strakhov.To test modern sediments, bottom grabbers and shock tube were used. The sampling points were selected based on the materials of continuous seismic profiling and bathymetric bottom survey.As a result of the studies, mapping of the relief and modern sediments within the Kara and Pechora Seas has been carried out and it has been found that the Pechora basin is characterized by various types of sediments and deposits (pelitic mud, aleurite-pelitic mud, clay, silt, sand, moraine deposits), and the Kara Sea is mainly inhabited by thin sediments (pelitic mud). A small amount of sand and siltstone among the bottom sediments of the Kara basin should be associated with an insignificant introduction of terrigenousclastic material from the continent and its deep water. The wide distribution in the southern and central parts of the Pechora Sea of psammiticfacies is due to its shallow water, intensive supply of a large amount of sand-silty material by river flow, processes of solifluction and thermal abrasion of the coasts. In 2020, the next flight of the R/V Akademik Nikolai Strakhov is planned to continue the study of the upper sedimentary stratum and topography of the seabed of the western sector of the Russian Arctic. The purpose of the study is to substantiate the most likely scenario for the development of changes in the natural environment on the shelf, associated primarily with a reduction in the area of ice cover.
  • Background concentrations of heavy metals and other chemical elements in the sediments of small lakes in the south of Karelia, Russia

    Slukovskii, Z. I. (2020)
    The average background concentrations of 42 elements, including heavy metals which are the most dangerous pollutants of the environment, were calculated based on detailed research of sediments of 15 small lakes in the south of the Republic of Karelia. The sediment samples from the lakes were collected from 2016 to 2018. The main items of equipment were a gravity sampler Limnos and hand sampler. The former is capable of producing a 60 cm core and dividing it into 1 cm layers, the latter can enter sediment to a depth of 15 m. All samples were prepared by chemical analysis and measured using uniform methods. The concentrations of chemical elements were taken by the mass-spectral method on a ХSeries-2 ICP-MS. To reveal the layers accumulated in the pre-industrial period, similar research of the area of the Murmansk region and countries of the Scandinavian Peninsula were used. Besides this, the geochemistry and geochronology of lake studies of the author were also used. Eventually, from 73 to 76 samples were taken for an assessment of background concentrations of heavy metals and other elements in the sediments of the lakes from Karelia's south. Given that the data obtained do not obey the normal distribution law, which is often found in geochemistry, the median sample was taken as the averaged background concentration of chemical elements. The results were similar to analog data for neighboring regions, including the Murmansk region and Scandinavian countries. Moreover, the levels of accumulation of chemical elements in lake sediments of Karelia's south are similar to some of the data for stream sediments of the studied region. The exceptions were elements controlled by terrigenous fractions of the stream sediments. This fraction is more rapidly accumulated in the stream and river sediments than in lake sediments. New data can be used for future environmental and geochemistry studies of the sediments of small lakes subject to anthropogenic impact.
  • Assessment of the efficiency of passive thermal protection system of rock massif

    Gusak, S. A.; Orlov, A. O.; Smirnov, Y. G.; Biryukov, V. V.; Palivoda, A. A. (2020)
    The problem of ensuring the stability of rock mass is of particular importance in the conditions of thermal interaction of mine workings with permafrost rocks. The paper presents the results of studying the effectiveness of passive thermal protection system of permafrost massif. Based on a numerical modeling by use of ANSYS FLUENT software complex, studies of thermal interaction of a large-span chamber working and permafrost massif have been performed. On the example of a hypothetical three-dimensional model of mine working with different variations in the material composition of the protective structure (lining) of working and the use of convective heat transfer in the technological channel (air gap), it has been performed the calculated study of the features of the temperature regime of the lining structural elements. There has been carried the estimation of the predicted depth of thawing of rock depending on the design and material composition of the lining and the duration of the thermal impact on the rock massif. The influence of the thermal resistance of the mine working protective structure on the depth and dynamics of thawing rock massif has been studied, the structure determines the conditions of preservation of its cryogenic state and requirements for mining systems of regulation of the thermal regime. The temperature gradients formed in the structural elements of the lining, which can contribute to the occurrence of thermal stresses that have a negative impact on the stress-strain state of the protective structure of the mine working have been founded. On the example of the accepted model representations of the technological channel (temperature of the entering air, width of the channel) the weak influence of heat exchange due to free convection on the intensity of thermal interaction of the working and rock massif has been shown. To reduce the thermal impact on the protective structure of the mine working and the permafrost massif it is necessary to increase the intensity of heat exchange in the technological channel by decreasing the temperature of the air entering the channel, or using the forced convection based on the organization of a special ventilation system.
  • Environmental protection and sustainable development of the mining industry in Murmansk Region, Russia

    Makarov, D. V.; Borovichev, E. A.; Klyuchnikova, E. M.; Masloboev, V. A. (2020)
    The mining complex of the Murmansk region (Russia) has a negative impact on natural ecosystems and worsens the quality of the environment, since the development of non-renewable mineral resources is associated with a significant transformation and destruction of natural communities. In the Murmansk region, where the mining industry forms the basis of the regional economy, the research aimed at achieving sustainable development goals involves the search for 1) new integrated approaches to ensure the development and implementation of environmentally friendly technologies for the extraction and processing of minerals; 2) managerial decisions supporting the transition to a circular economy; 3) the establishment and development of protected areas, including compensatory; 4) the restoration of disturbed landscapes; 5) the development of nature-like technologies for the recovery of valuable components from minerals, and 6) the protection of the environment. Futhermore, there is need for a constant search for some balance of interests of local communities and mining corporations in the context of environmental protection and economic development in order to maintain social sustainability. Without designing the foundations of the state policy for the transition to a closed-loop economy, the implementation of even existing technologies will be too slow. There is a survey of nature-like technologies developed in the Kola Science Center of the Russian Academy of Sciences for processing minerals and protecting the environment, rehabilitation of disturbed areas exposed to industrial air pollution, reclamation of the water and land areas polluted by oil and oil products as well as examples of territorial nature conservation that do not block the development of processing minerals.
  • Fadeev Stream and spring of the same name: Water quality and geo-ecological characteristics

    Glazova, V. A.; Gaponenkov, I. A.; Fiodorova, O. A.; Dauvalter, V. A. (2020)
    Research of the geoecological and hydrochemical characteristics of the water of the Fadeev Stream (surface source) and the spring "Fadeev Stream" (underground source) located in the Kola District of the Murmansk Region has been carried out in order to identify the influence of the anthropogenic factor on the formation of its hydrochemical composition, caused primarily by the consequences of construction and reconstruction of Eastern bypass highway located around the city of Murmansk. The sampling has been taken accounting the requirements of regulatory documents to perform measurements; the tests have been carried out according to standard methods of hydrochemical analysis. In the course of the study, it has been found that the waters of the Fadeev Stream and the underground source are of natural origin; there is no influence of technogenic factors. The Fadeev Stream water is very soft, slightly mineralized, with significant variations in color depending on the season, there is swamp nutrition of water bodies. The spring water can be described as slightly acidic, very soft, ultra-unleavened with a variable chemical composition depending on the season of the year. The increase in the content of pollutants in the spring water is observed during periods with the most intense precipitation and heavy snowmelt. Precipitation can wash out pollutants from the soil or parent rock. A comparison of the qualitative composition of water from surface and underground water sources has shown that at the sampling points, natural waters have a natural genesis and are not affected by anthropogenic factors.
  • The ages and rock mineral composition of the Pechenga eastern frame, the Kola Region

    Nitkina, E. A.; Kaulina, T. V.; Kozlov, N. E. (2020)
    The research and dating of rocks in the area of the Central Kola block (the Kola Peninsula) is due to the need to develop the Lyceum uranium ore area, the most promising for uranium mining in the Kola region, located in close proximity to the study area and composed of similar gneisses from the Kola series. Within the Central Kola block, Archean complexes are represented by granite-gneisses and migmatites with relicts of biotite-plagioclase, biotite-amphibole-plagioclase gneisses, amphibolites, garnet-biotite-plagioclase and aluminous gneisses containing interlayers of ferruginous quartzite (quartz metasomatites) of various capacities. The rocks are repeatedly metamorphosed in conditions from high-temperature steps of the amphibolite facies to the granulite facies. Geological and geochronological methods have established the sequence of geological processes manifested in the rocks of the Kola series of the northwest framing of the Pechenga structure. The results of U-Pb dating are determined by zircon grains of the following genesis: metamorphic – in gneiss; magmatic and metamorphic – in metagabbro; metamorphic and metasomatic – in quartz metasomatite. The data obtained have made it possible to establish the age sequence of geological processes: 2.8 Ga – the time of metamorphism of garnet-biotite gneisses; 2,722 ? 9 Ma – crystallization of granodiorites; 2,636 ± 41 Ma – the formation of aplitic granites; 2,620 ? 16 Ma – the emplacement of pegmatites; the age of aplitic granites and pegmatites marks the final stages of the Archean evolution of the region; 2,587 ± 5 Ma – the emplacement of gabbroids, 2,522–2,503 Ma – the period of the thermal process associated with the formation of quartz metasomatites during the metamorphism of gabbro and garnet-biotite gneisses; 2,507 ± 7 Ma – metamorphism, schist and budding of gabbroids.
  • Geodynamics and metallogeny of the Keivy domain (Baltic Shield)

    Kozlov, N. Е.; Sorokhtin, N. О.; Martynov, E. V.; Marchuk, T. S. (2020)
    Geodynamic and petrogeochemical study of the Keivy domain in the Baltic Shield has shown that it was overlapped by surrounding microcontinents in the Archean. As a result, the Baltic Shield was subject to cratonization. Thus, the Keivy microcontinent can be considered as the most ancient known median massif of the continental crust. Specific features of its geodynamic evolution predetermined conditions for formation of unique in scale stratiform deposits of alumina raw materials on the surface of the microcontinent. The paper describes and justifies the mechanism of alumina formation by physical-chemical decomposition of Archean and early Proterozoic metamorphosed sedimentary complexes in the Kola region of the Baltic Shield. Besides, the study of metallogenic features of transformation processes in the Archean continental crust of the Keivy microcontinent and its rimming suggests that carbonaceous schists of the Keivy domain that formed in the sedimentary cover can be significantly rich in nanogold. It will allow considering the central part of the Kola region as a major gold-bearing province. The authors believe that the metallogenic forecast based on geodynamic reconstructions is promising for further research of early Precambrian complexes. This work continues a series of publications on structural-material study of the Keivy domain.
  • Structures of sulfide melt crystallization as an indication of metamorphism of the ores in the Oleninskoe gold deposit

    Kalinin, A. A.; Savchenko, Ye. E. (2020)
    Multiphase fine aggregates of galena, pyrrhotite, freibergite, pyrargyrite, diaphorite, fizelyite, uchucchacuaite, ullmanite, and some other minerals are found in the ores of the Oleninskoe gold deposit in the Kolmozero-Voronya greenstone belt (Kola Peninsula, Russia). The aggregates are considered to be the product of crystallization of sulfide melt formed of the minerals of low-melting-point chalcophile elements (Zn, Ag, Cd, Tl, Pb, As, Sb, Bi, Se, Te, etc.) during heating to the temperature above 500 °C. This origin of the aggregates is affirmed by: 1) multiphase composition (up to 6 minerals) of the aggregates; 2) absence of signs of replacing early minerals by the late ones; 3) essential presence in the aggregates of the minerals of chalcophile elements Ag, Pb, Sb, i. e. elements with a low melting point of their compounds; 4) roundish droplet form of inclusions of minor minerals in the main sulfide, and 5) aggregates' position at the boundary sulfide – quartz or in fractures in vein minerals. Partial melting and crystallization of sulfide melts took place during Paleoproterozoic metamorphic event, when the Neoarchean sulfide-bearing rocks were mid-amphibolite metamorphosed under the temperature > 500 °C. Signs of the Paleoproterozoic metamorphism are found in the ores of the neighboring Cu-Mo porphyry Pellapahk deposit as well.
  • Seismic effect of industrial explosions of GOK Kostomuksha

    Zueva, I. A.; Lebedev, A. A. (2020)
    Active development of quarries in the Republic of Karelia contributes to the improvement of the control system of the parameters of drilling and blasting operations with the aim of ensuring the safety of buildings and structures near mining facilities. During the study of the seismic effect of industrial explosions, the technology of blasting has been considered and a typical scheme of blasting at a mining enterprise has been described. In the quarries of the Kostomuksha mining and processing plant, to reduce the seismic effect, short-blasting is used. The created monitoring system in Karelia makes it possible to select not only teleseismic earthquakes, but also regional and local scale events on the seismic records. Explosions are recorded by seismic stations of the Karelian network and other regions if the magnitude of the event is more than 1.7. As a result of the waveforms' analysis of the records of the seismic station KOS6, located a few kilometers from the quarries, a clear entry of the transverse wave has been noted. The values of the local magnitudes of the explosions established during the six months of 2018 vary from 1.5 to 2.5 and do not exceed 3. The constructed averaging line shows the dependence of magnitude on the total charge; facts of its growth are noted with an increase in the total mass of the charge, as well as significant spread of data from the averaging line. In the course of the study, the possibility of reducing the seismic effects of industrial explosions through the use of effective short-delayed invocation schemes has been determined.
  • Residual magnetization of various genetic rocks and ores of the Kola Region under the influence of mechanical oscillations

    Zhirova, A. M. (2020)
    The paper considers magnetoelastic phenomena in rock samples. Research is of interest for solving problems of nonlinear geophysics, as well as of some issues of materials science. Magnetite-bearing rocks and ores have been sampled in different geological structures of the Kola region in order to study their magnetoelastic properties. All samples have been subject to elastic mechanical oscillations in laboratory conditions. The experiment has been conducted under changing impact parameters of acoustic waves. The effect of signal amplitude on magnetic properties of the samples has been first studied using magnetite-bearing amphibolites from the Serpovidny Ridge structure. According to results of the experiment, it is considered reasonable to use a pulse signal with higher amplitude in the future. An effect of a signal direction regarding a vector of residual magnetization has been studied, using rocks with different ferromagnetic contents. Values of natural residual magnetization of the studied samples vary from 100 А/m to 0.5 А/m. The study has indicated some relation between a spatial behavior of a vector and a direction of the acoustic impact in rocks with high magnetite content. In particular, the spatial location of the vector changes considerably, when the angle between the direction of the acoustic wave front and the magnetization vector of samples is 100 degrees and more. No statistically significant relations or patterns have been identified for low-magnetic samples. At the final stage, the effect of duration of elastic mechanical oscillations impact on magnetic properties of rocks has been studied. Results of the research also indicate an interrelation between an impact of this acoustic effect and an amount of the magnetic matter in the rock. Thus, a significant response of the samples' magnetic state is registered during the acoustic impact on rocks with high ferromagnetic content. In general, it has been concluded that studying electromagnetic effects on high-magnetic samples is more promising compared to rock samples with lower ferromagnetic content.
  • Study of the structure and seismicity of the near-surface zone of the earth's crust at the White Sea seismogenic zone on the Kola Peninsula

    Demakhin, A.Yu. (2020)
    The Kandalaksha-Bothnian deep fault is the subject of a comprehensive geological and geophysical study in connection with the development of the Shtokman gas field on the Kola Peninsula. In the process of studying the structure and seismicity of the near-surface zone of the earth's crust in the vicinity of the route of the planned Shtokman – Volkhov gas pipeline, the following have been carried out: 1) lineament analysis of the topographic map where the lines of the supposed faults were plotted, corresponding to the beds of the largest rivers, large streams, elongated lakes and bays; 2) analysis of the geological profile along the class I levelling line; 3) comparison of the lineament analysis results with the results of the geological profile analysis along the levelling line. When determining seismic risks, the sources of earthquakes occurred in the study area have been mapped; the impact of recorded earthquakes on the designed pipeline has been estimated and seismic intensity has been calculated at the point of the pipeline route design closest to the earthquake epicenter. Georadar studies of areas of the Kandalaksha seismogenic zone, interpretation and analysis of the obtained radarograms have made it possible to identify lineaments that coincide in location with faults, subsurface boundaries indicated on the geological section, outline the layers of bulk and natural soils and rocks with high accuracy and identify areas with anomalous physical and mechanical properties, fracture zones, as well as the boundary of the rocky base under the moraine and to conclude that the earthquakes occurred theoretically would not have had a significant impact on the projected pipeline. Thus, it is possible to carry out industrial construction in the study area (including linearly extended objects), taking into account the limitations caused by the Kandalaksha-Botnichsky deep fault seismicity indices obtained during georadar analysis.
  • Improving the process of heat treatment of the stingray stellate

    Astramovich, V. L.; Golubeva, O. A. (2018)
    The results of developing a method for combined blanching (water – steam) of a stingray stellate have been presented. The proposed method completely excludes the process of preliminary wetting and, as a consequence the hydration of stingray meat; allows one to get a semi-finished product suitable for further processing for culinary purposes, as well as for canning. Analysis of the mass-size characteristics of wings of stingray stellate, caught in the Barents Sea, made it possible to identify a group of raw materials with a specific surface area 0.2560 ± 0.05 m2/kg, which corresponds to 75 % of the block weighing 10 kg with an average mass of the sample equal to 161.33 g. The presented experimental setup allows investigating the process of blanching with water, steam or a combined method of raw materials of both plant and animal origin. To plan the experiment, the combinatorial squares method has been applied. The effectiveness of urea removal from the stingray stellate meat has been confirmed experimentally by comparing the mass fraction of carbamide in muscle scate tissue before and after preliminary heat treatment accounting the characteristics of the product under study. The developed mode of combined blanching (water – steam) for stingray is characterized by an effective removal of urea (42.5 %) and can be used for industrial blanchers of processing lines. The mathematical model of the duration of steam treatment depending on the water temperature and the duration of water treatment, makes it possible to predict the regime of preliminary heat treatment of raw materials.
  • Enzymatic conversion as a method of producing biologically active peptides

    Agarkova, E. Yu.; Kruchinin, A. G. (2018)
    The growth of food products output volume including dairy products enriched by food ingredients with different biological effects is caused by deterioration of socioeconomic conditions, unstable ecological situation and unbalanced nutrition. The basic types of milk proteins proteolysis and the benefit of enzymatic catalysis over alkaline and acid have been considered. The data relating to usage of milk proteins hydrolysates in different fields of specialized and medioprophylactic nutrition depending on degree of hydrolysis and molecular weight of peptides have been presented. The substrate specificity of enzymatic preparations used in dairy industry in respect to impart the specified functional properties to milk protein has been analyzed. The impact of free amino-acids content in hydrolysates and the necessity to select enzymatic composition subject to the data relating to amino-acid sequence of protein and ferment substrate specificity has been described. Herewith protein hydrolysate obtaining with acceptable organoleptic properties and predicted biological effects is possible. The investigation analysis in the field of the functional products manufacture using protein containing milk raw material for production of protein compositions with the following creation of products on their basis has been carried out. The possibility to use the strategies of the directed enzymatic hydrolysis on obtaining of peptide compositions possessing hypotensive properties due to inhibition of angiotensin-1-converting ferment (ACF) by short oligopeptides has been demonstrated. Moreover, milk protein hydrolysates contain short peptides possessing cytoprotective and immunomodulatory action. Besides, milk protein hydrolysates exhibited the presence of antioxidant activity regarding different radicals in the systems with lipids oxidation.
  • The enzymatic activity of various organs and tissues of Far-Eastern trepang as a system of indicators of maturation and quality of products

    Pivnenko, T. N.; Pozdnyakova, Yu. M.; Kovalev, N. N.; Mikheev, E. V.; Esipenko, R. V. (2018)
    The activity, substrate-inhibitory specificity, temperature and pH dependence, seasonal changes in proteolytic and nucleolytic enzyme systems of the digestive tract, muscle and reproductive trepangs tissues have been considered. The different-rule variability of enzyme activity at different stages of development has been shown. At the stage of growth proteolytic enzymes of the intestinal tract have the greatest activity, which is significantly reduced during spawning. In muscle tissue, there are opposite processes associated with changes in the strength. Separation of proteases of the trepang digestive tract by ion exchange chromatography has been carried out. Two peaks of proteins showing trypsin activity corresponding to the isoforms of this enzyme possessing a negative charge have been detected. The molecular weight of the corresponding peaks determined by the electrophoresis method is 26 and 28 kDa. The data obtained are similar to those established earlier for other types of holothurians. Determination of the activity of proteases of trepang muscle tissue in different seasons has shown a low level of proteolytic activity during the growth period. The activity values in acid and neutral proteases are close to each other. The lowest activity has been detected in alkaline proteases. During the spawning period, the activity of acid proteases increases significantly in the muscle tissue, proteolysis remains at the same level in the neutral and alkaline zone. Reproductive tissue processes of growth and formation of the gonad is accompanied by high activity of the acidic deoxyribonucleases. At the stage of spawning it is significantly reduced, in the post-spawning period it is completely absent. Interactions of enzymes with substrates and inhibitors allow preventing the presence of cathepsins, metalloproteases and serine proteases in the trepang intestinal. The reduction of strength of the muscle tissue may be due to the action of metalloproteases affecting on the structure of the collagen matrix. The results are recommended for the development of rational methods of trepang processing by regulating the activity of enzymes.
  • Antioxidant complex extracts from fucus algae of the Barents Sea

    Obluchinskaya, E. D. (2018)
    A new method for obtaining antioxidant complex extracts from fucus algae has been proposed at the example of three mass species of the Barents Sea: Fucus vesiculosus, Fucus serratus and Fucus distichus. The chemical composition and antioxidant activity of new phytocomplexes has been studied. The high value of the main antioxidants – fucoidan, polyphenols, free amino acids and ascorbic acid – has been shown. For the most important indicators from the antioxidant activity point of view (fucoidan, polyphenols, ascorbic acid), a technological yield has been calculated in terms of the content of BAS in dry raw materials. The use of the new method has made it possible to achieve the most complete extraction of polyphenols and ascorbic acid (over 90 %) from algal raw materials with the simultaneous increasing the percentage of these substances in extracts of fucus algae (25–30 % for polyphenols). The content of fucoidan equal to 50–60 % also advantageously distinguishes the dry extracts obtained by the developed method from the extracts described in the literature. The antioxidant activity of dry extracts of fucus algae has been tested by comparing samples with quercetin, which belongs to a group of plant flavonoids. As a result of the study, a high antiradical activity of all the extracts studied with respect to the DPPH radical has been established. The greatest antiradical activity is characteristic of extracts from the Fucus vesiculosus. The IC50 value (0.035–0.038 mg/ml) has been compared to the IC50 of the quercetin comparison agent (0.026 mg/ml).
  • Conditions of acetic acid producing by Brettanomyces yeast

    Novikova, I. V.; Yuritsyn, I. A.; Muravev, A. S. (2018)
    Brettanomyces yeast has found their application in brewing (Lambic and Guezze style). Acetic acid obtained during fermentation by Brettanomyces yeast participates in the synthesis of ethers responsible for the taste and aroma component of the beverage. In this study the ability of four yeast strains Brettanomyces (intermedius, bruxellensis, custersianus, and clausenii) to produce acetic acid on a medium containing glucose has been determined. The strain B. bruxellensis has been found to be the most effective for the biological acidification of the medium including brewing. The optimum mode of air output at full consumption of glucose and achievement of maximal values of volumetric equal to 0.06 g/(l*h) and specific yield of acetic acid equal to 0.43 g/(g*h) has been determined, it is equal to 300 l/h. Influence of temperature and mixing of the medium on the production of acetic acid by B. bruxellensis in an environment containing glucose at the temperature of 26, 30, 34 °C and the speed of the mixer 250, 350, 450 rpm has been investigated by statistical methods. The optimal conditions for the maximum volumetric output of acetic acid – 0.114 g/(l?*h) are the temperature 28 °C and the mixer speed 250 rpm.
  • Chinese mitten crab Eriocheir sinensis domesticates a new habitat

    Shklyarevich, G. A.; Kuchko, Т. Yu. (2018-06-30)
    The fact of habitation of an invading species – the Chinese mitten crab Eriocheir sinensis – in the Lakhtinskaya Bay of Lake Onega has been registered. It should be mentioned that the first specimens were caught near the Pukhtinskiy Islands of Lake Onega in 1993, and in 2006 – in the Kondopoga Bay and the Povenets Bay of this lake. In 2017, the detection of the Chinese mitten crab was recorded in the Lakhtinskaya Bay of Lake Onega. The morphometric analysis data of these animals have been given. The obtained data can be used to create an information base of the studied species for further analytical examination of its growth and age, life cycle characteristics and reproduction, nutrition and migration movements, as well as for forecasting the ecological situation.

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