control harmful algae blooms (HABs), methods based on natural mechanisms are now required. We investigated the effects of an algicide derived from macrophyte metabolites, namely mixtures of gallic, tetradecanoic, heptanoic, and octanoic... more
control harmful algae blooms (HABs), methods based on natural mechanisms are now required. We investigated the effects of an algicide derived from macrophyte metabolites, namely mixtures of gallic, tetradecanoic, heptanoic, and octanoic acids (1:1:1:1 mass ratio, a total concentration of 14 mg/L), on the biomass of cyanobacteria and other plankton and the production of microcystins under experimental conditions. Two types of microcosms have been created: simple (microalgae, cyanobacteria, and zooplankton) and complex (microalgae, cyanobacteria, zooplankton, and planktivorous fish). We observed the dynamics of the phytoplankton structure, the concentrations of microcystins and chlorophyll-a, hydrochemistry, and the status of zooplankton and fish in both types of microcosms with and without algicide for one month (from 19 July to 19 August 2021). The introduction of algicide caused changes in phytoplankton structure, a drop in cyanobacterial biomass, and a decrease in the total concentration of microcystins. Surprisingly, the contributions of the most toxic microcystins (LR form) were higher in both types of microcosms exposed to algicide than in microcosms without algicide. The inhibitory effect on the cyanobacterial biomass was most significant in complex ecosystems (containing fish), while it was only observed at the end of the exposure in simple ecosystems. Not only algicide but also phytoplankton consumed by fish and zooplankton, as well as nutrient excretory activity by both consumers, seem to have impact on cyanobacterial biomass. This study found that the using chemical substances similar to macrophyte metabolites can help regulate HABs and cyanotoxins. However, the results differ depending on ecosystem type.
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The study of exogenous metabolites of algae-bacterial communities in the laboratory accumulative culture obtained from natural river water was conducted using gas chromatography-mass spectrometry. Exometabolites of the algae-bacterial... more
The study of exogenous metabolites of algae-bacterial communities in the laboratory accumulative culture obtained from natural river water was conducted using gas chromatography-mass spectrometry. Exometabolites of the algae-bacterial community (including microalgae and cyanobacteria) in the culture medium were represented by saturated, unsaturated, and aromatic hydrocarbons, carboxylic acids, phenolic, and terpene compounds and their derivatives. Possible biological activities of the discovered exometabolites are considered. The study has demonstrated that an increase in the number of main groups of microorganisms, along with changes in the composition of algae and cyanobacteria, are responsible for the increase in the composition and concentration of metabolites in the microecosystem’s culture medium after one month of cultivation. The presence of octacosane in high concentration (0.0603 mg/L; 23.78% of the total content of low molecular weight organic compounds) by the end of exposure accumulative culture is associated with the strong development of the cyanobacterium Gloeocapsa sp. in the presence of diatom algae of the genus Navicula and green algae of the genera Chlorella and Scenedesmus. Due to the need to comprehend the ecological and biochemical mechanisms of the formation and functioning of algae-bacterial communities, as well as to predict potential paths of transformation and evolution of aquatic ecosystems, the specificity of exometabolite complexes of algae and microorganisms, as well as their allelopathic and other biochemical interactions in freshwater ecosystems, requires further serious study.
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To control harmful algae blooms (HABs), methods based on natural mechanisms are now required. We investigated the effects of an algicide derived from macrophyte metabolites, namely mixtures of gallic, tetradecanoic, heptanoic, and... more
To control harmful algae blooms (HABs), methods based on natural mechanisms are now required. We investigated the effects of an algicide derived from macrophyte metabolites, namely mixtures of gallic, tetradecanoic, heptanoic, and octanoic acids (1:1:1:1 mass ratio, a total concentration of 14 mg/L), on the biomass of cyanobacteria and other plankton and the production of microcystins under experimental conditions. Two types of microcosms have been created: simple (microalgae, cyanobacteria, and zooplankton) and complex (microalgae, cyanobacteria, zooplankton, and planktivorous fish). We observed the dynamics of the phytoplankton structure, the concentrations of microcystins and chlorophyll-a, hydrochemistry, and the status of zooplankton and fish in both types of microcosms with and without algicide for one month (from 19 July to 19 August 2021). The introduction of algicide caused changes in phytoplankton structure, a drop in cyanobacterial biomass, and a decrease in the total con...
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The qualitative and quantitative component composition of low molecular weight volatile organic compounds (VOCs) of the essential oil of the floating-leaf pondweed (Potamogeton natans L., Potamogetonaceae family) growing in various lakes... more
The qualitative and quantitative component composition of low molecular weight volatile organic compounds (VOCs) of the essential oil of the floating-leaf pondweed (Potamogeton natans L., Potamogetonaceae family) growing in various lakes of the Karelian Isthmus (North-West of the Russian Federation) in the fruiting stage was investigated in detail for the first time by gas chromatography-mass spectrometry. The low molecular weight metabolome (LMWM) of P. natans contained 138 components, 128 of which were identified. VOCs belonging to esters, alcohols, and various functional groups dominated the LMWM of floating leaf pondweed from mesotrophic and eutrophic lakes. A significant similarity was found between the component composition of VOCs of floating leaf pondweed from mesotrophic and eutrophic lakes. Many of the substances found in the LMWM of P. natans can be attributed to biologically active compounds. This opens up prospects for the use of this plant (particularly manool and ecdy...
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Abstract The issue of the formation of the compound composition of low-molecular-weight organic compounds in aquatic macrophytes, which make up their low-molecular-weight metabolism, has hardly been studied when introducing them into new... more
Abstract The issue of the formation of the compound composition of low-molecular-weight organic compounds in aquatic macrophytes, which make up their low-molecular-weight metabolism, has hardly been studied when introducing them into new habitats. The study aims to compare the component composition of the low-molecular-weight metabolome of sago pondweed ( Potamogeton pectinatus L.) on the low-molecular-weight organic compounds contained in the essential oil from the invasive population in the Lake Ladoga and the populations from the native range in Astrakhan Region, Russia. Gas chromatography–mass spectrometry was the major research method. Upon the invasion of P. pectinatus into Lake Ladoga, there was a change in the content of various groups of low-molecular-weight organic compounds in the essential oil and a change in the complex of major components. Fatty acids (29.3–40.0%) and ketones (14.5–18.5%) prevailed in the low-molecular-weight metabolome of sago pondweed in the lakes of the native range. Ketones (27.4%) and aldehydes (18.1%) were the main groups in this species inhabiting Lake Ladoga. About a third of the compounds in the composition of the low-molecular-weight metabolome were specific both to the invasive population of the sago pondweed in the Lake Ladoga and to the population from the lakes of the native range. The plasticity of the metabolism of P. pectinatus allows it to adapt to a wide spectrum of abiotic conditions and different biological environments and to settle in new habitats, primarily those under anthropogenic impact.
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Особое значение для всего региона Северо-Запада имеет крупнейшее в Европе озеро Ладожское. Постоянное слежение за его экологическим состоянием жизненно необходимо для решения самых разнообразных задач научного и практического характера.... more
Особое значение для всего региона Северо-Запада имеет крупнейшее в Европе озеро Ладожское. Постоянное слежение за его экологическим состоянием жизненно необходимо для решения самых разнообразных задач научного и практического характера. Цель публикации – на основании комплексных исследований основных биологических сообществ Ладожского озера (фитопланктон, макрофиты, водные грибы, бактериопланктон, зоопланктон, макро- и мейобентос) представить информацию по его современному экологическому состоянию и описать изменение экосистемы озера в конце XX – начале XXI в. Объединенные данные по всем основным гидробиологическим сообществам на основании исследований последнего десятилетия (2007–2017 гг.) позволяют заключить, что трофический статус центральной части акватории Ладожского озера оценивается как слабомезотрофный (при олиготрофном характере гиполимниона), северной – как олиготрофный, западной – как мезотрофный, южной части (Свирская и Волховская губы) – как слабоэвтрофный. Средние вели...
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Research Interests: Earth Sciences, Biology, Ecology, Periphyton, Aquatic Invertebrates, and 12 moreBiological Sciences, Environmental Sciences, Statistical Significance, Primary Production, Typha, Phragmites, Invertebrate, Macrophyte, Chlorophyll a, Dry Weight, Environmental factor, and Stepwise multiple linear regression
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The study of low-molecular-weight organic compounds (LMWOCs), which are metabolites of aquatic plants, lags far behind terrestrial habitats. Our research has shown that the number of components of the low-molecular-weight metabolome... more
The study of low-molecular-weight organic compounds (LMWOCs), which are metabolites of aquatic plants, lags far behind terrestrial habitats. Our research has shown that the number of components of the low-molecular-weight metabolome (LMWM) of specific aquatic macrophytes can be more than 200, and there are more than 1500 such compounds in total. We have shown that there are patterns of formation and change of LMWM of macrophytes both depending on the geographical growth of plants and depending on the impact of various biotic and abiotic factors. Among the various functions of LMWOCs of aquatic macrophytes, particular attention is paid to the study of the phenomenon of allelopathy.
Research Interests: Biology and Metabolomics
Introduction. The Shchuchiy Bay is located in the western part of the skerry area of Lake Ladoga near the town of Priozersk. For almost 20 years, the bay has experienced an anthropogenic impact from the ingress of untreated wastewater... more
Introduction. The Shchuchiy Bay is located in the western part of the skerry area of Lake Ladoga near the town of Priozersk. For almost 20 years, the bay has experienced an anthropogenic impact from the ingress of untreated wastewater from the Priozersk Pulp and Paper Mill (PPM). Systematic microbiological studies of the Shchuchiy Bay ecosystem were started in the middle of the 1970s by the Institute of Limnology of the Russian Academy of Sciences and continued after the PPM closure in 1986. Materials and methods. The ecosystem of the bay was studied in detail during the growing season of 2013–2014; periodic studies were carried out in 2015–2018. Retrospective data were also used for the analysis. Water samples were taken at four stations from the surface horizon. The following microbiological indicators were determined: the abundance of bacterioplankton and the percentages of various morphological types of bacterial cells. Results and discussion. A comparison of the quantitative le...
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Harmful algal “blooms”, or HABs, is a hazardous natural phenomenon that often occurs under the influence of anthropogenic factors, for example, during the anthropogenic eutrophication of water bodies. An increase in the frequency and... more
Harmful algal “blooms”, or HABs, is a hazardous natural phenomenon that often occurs under the influence of anthropogenic factors, for example, during the anthropogenic eutrophication of water bodies. An increase in the frequency and duration of cyanobacterial “blooms” carries a number of serious threats, including local and global degradation of water resources and the impact of cyanotoxins. There are various methods of fighting cyanobacterial “blooms” - physical, chemical, the use of bacterial preparations, etc. However, these methods are not effective enough and, most importantly, do not allow effectively solving the problem of suppressing HABs in water bodies without damage to other components of the aquatic ecosystem. Allelopathy is a natural phenomenon for both stimulatory and inhibitory effects of one plant upon another including microorganisms that resolves this problem. Allelochemicals of macrophytes can be considered as natural algaecides and become the basis of a nature-l...
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Abstract Gmelinoides fasciatus is a successful invasive amphipod (Amphipoda, Crustacea) that dispersed from Lake Baikal to various waterbodies. Here we studied whether Baikal conditions are optimal for G. fasciatus in terms of... more
Abstract Gmelinoides fasciatus is a successful invasive amphipod (Amphipoda, Crustacea) that dispersed from Lake Baikal to various waterbodies. Here we studied whether Baikal conditions are optimal for G. fasciatus in terms of thermotolerance and investigated lethal temperatures, 70 kDa heat shock protein level, energy metabolism, and antioxidant defense of animals from three geographically distant waterbodies under changing temperatures. We used acute heat exposure to 28 °C to assess the median lethal times and gradual temperature increase from 6 °C to determine the lethal temperatures. Mortality under heat shock was explainable by the baseline content of Hsp70 that correlated with thermal history. But it was not the case under gradual temperature increase where Hsp70 levels became similar and the mortality pattern changed. The most thermotolerant amphipods from the Gulf of Finland demonstrated a higher amount of free glucose during the temperature increase that may be related to the higher salinity of this waterbody and less energy required for ion regulation. Even though concentrations of major physiological ions in Lake Baikal are lower than in Lake Ladoga, G. fasciatus from Ladoga was slightly more sensitive to the gradual temperature increase. This difference could be explained by the influence of high levels of humic and other potentially toxic substances in Lake Ladoga indicated by increased activities of catalase and glutathione S-transferase. Importantly, all G. fasciatus populations accumulated relatively low levels of lactate during the temperature increase, which may reflect the ability of this invasive species to effectively maintain aerobic metabolism under various conditions.
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Alkylphenols (APs)—nonylphenol (NP) and octylphenol (OP)—are well-known environmental contaminants due to their widespread application and have been identified as endocrine-disrupting chemicals. A novel APs-tolerant fungus designated F6... more
Alkylphenols (APs)—nonylphenol (NP) and octylphenol (OP)—are well-known environmental contaminants due to their widespread application and have been identified as endocrine-disrupting chemicals. A novel APs-tolerant fungus designated F6 was isolated from the bottom sediments of the coastal part of the Eastern Gulf of Finland (Neva Bay) and was identified as Aspergillus tubingensis F6 based on ITS sequencing and morphological analysis. The APs presence caused morphological and ultrastructural changes in fungal cells. Major differences were detected in mitochondria, vacuoles, and cell walls. Nonenzymatic antioxidants—pigments, reduced glutathione, exopolysaccharides—played important roles in A. tubingensis F6 resistance to APs toxicity. A low level of lipid peroxidation showed that the protective effects of the antioxidant system were sufficient despite the fact that antioxidant enzymes activity levels were low. Another defense response employed by A. tubingensis F6 against the tNP- and 4-tert-OP-induced stress was based on the ability of the strain to efficiently utilize xenobiotics. After 120 h of cultivation, < 10% of APs (initially added to the culture at 100 mg/l) remained in the culture medium of A. tubingensis F6. The APs degradation by A. tubingensis F6 led to the formation of nontoxic products. These data indicate the potential role for A. tubingensis F6 in APs degradation in natural environments, as well as its possible biotechnological application in wastewater treatment to remove xenobiotics with endocrine activity. To our knowledge, this is the first report demonstrating that marine-derived fungus A. tubingensis strain is capable of utilizing branched-chain NP and OP.
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The aim of the research was to study a removal of polycyclic aromatic hydrocarbons (PAHs) and phytoextraction of bromine (Br) from contaminated soils. The experiments using pea and wheat seedlings as potential candidates for soil... more
The aim of the research was to study a removal of polycyclic aromatic hydrocarbons (PAHs) and phytoextraction of bromine (Br) from contaminated soils. The experiments using pea and wheat seedlings as potential candidates for soil remediation were performed. The soil for the experiments was collected from a site slightly contaminated by some PAHs. Before planting, the soil was exposed to 20 mg of Br/kg of soil. In the soil taken from rhizosphere of pea and wheat, the concentrations of many PAHs decreased up to 7 times compared to the concentrations of the compounds in the initial soil. Pea was capable of more effectively influencing the soil PAHs than wheat. The growth of pea and wheat in the soil spiked with Br resulted in a significant increase of Br concentration in a plant. Concentration of Br in roots of pea and wheat increased 21 and 3 times, respectively. Bromine content in leaves of wheat and pea increased 10 and 4.5 times. This accumulation of Br in the plants led to a decre...
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Not much is known about the chemical composition of low-molecular weight secondary metabolites of Spirodela polyrhiza (L.) Scheiden. We aimed to investigate the composition of low molecular weight volatile organic compounds (VOCs) of S.... more
Not much is known about the chemical composition of low-molecular weight secondary metabolites of Spirodela polyrhiza (L.) Scheiden. We aimed to investigate the composition of low molecular weight volatile organic compounds (VOCs) of S. polyrhiza in the middle of the growing season by GC-MS. A GC-MS analysis of the essential oil of fresh S. polyrhiza was undertaken for the first time. It was found that in the middle of the growing season (in July) the essential oil of S. polyrhiza from a hypertrophic pond (Northwest Russia) contains 89 VOCs, 83 of which were identified. The major low-molecular weight metabolites of S. polyrhiza were manool (25.11%), biformen (12.83%) and phytol (8.05%), which are valuable in practical terms and can play a very important role in aquatic ecosystems. Further study of the composition of VOCs of S. polyrhiza growing in different water bodies and in different conditions (different hydrobiological environments) is necessary to understand the role of this species in hydrobiocenoses. The production of valuable VOCs from S. polyrhiza may be combined with other uses of this plant, e.g., biomass production, the treatment of wastewater with high nutrient concentrations (municipal, industrial and livestock farm wastewater). Large amounts of Lemnaceae biomass and VOCs can be the result of the purification of numerous water bodies that are exposed to duckweed bloom.
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ABSTRACT This article deals with the issues of studying low-molecular-weight volatile organic compounds (VOCs) of aquatic macrophytes growing in Russia under different environmental conditions and geographic regions. It is shown that the... more
ABSTRACT This article deals with the issues of studying low-molecular-weight volatile organic compounds (VOCs) of aquatic macrophytes growing in Russia under different environmental conditions and geographic regions. It is shown that the composition of VOCs and their content depend on the abiotic (geographical location of habitats, hydrological regime, and light conditions) and biotic factors (season and vegetation phase, distribution in different vegetative organs). Special attention has been paid to the functions performed by VOCs in aquatic ecosystems and their possible use for controlling phytoplankton development and algal &quot;blooms&quot; in inland water bodies.
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... Julia V. Krylova 1 ,; Evgeny A. Kurashov 2,* ,; Nikolay N. Korkishko 2. Article first published online: 16 DEC 2003. ... As a result of water exchange, the water in Lake Ladoga is renewed approximately every 1213 years (Kirilova... more
... Julia V. Krylova 1 ,; Evgeny A. Kurashov 2,* ,; Nikolay N. Korkishko 2. Article first published online: 16 DEC 2003. ... As a result of water exchange, the water in Lake Ladoga is renewed approximately every 1213 years (Kirilova & Malinina 1982). ...
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The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three... more
The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves,Nuphar lutea(L.) Sm., and two species of submergent macrophyte groups,Ceratophyllum demersumL. andPotamogeton obtusifolius(Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological signifi...
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ABSTRACT The difference of the evenness index (D E′ ) is offered for an assessment of the ecological state of zoobenthos communities. The index is deduced on the basis of the Shannon indexes calculated according to abundance and biomass... more
ABSTRACT The difference of the evenness index (D E′ ) is offered for an assessment of the ecological state of zoobenthos communities. The index is deduced on the basis of the Shannon indexes calculated according to abundance and biomass data and differentiates between these informational estimations (Shannon diversity) of evenness of species in any given community. Conclusions made by Pianka about the predomination of organisms with r and K life strategy in communities impacted and unimpacted by ecological stress, as well as the ABC-curves method suggested by Warwick, were used as the basis of the functioning mechanism for the suggested index. The examples of index applicability are demonstrated by an assessment of materials collected in freshwater, estuarine, and marine waterbodies during one-time surveys and long-term monitoring observations. The results are compared with zoobenthos assessments made on the basis of some other indexes. Conclusions concerning the efficiency of the D E′ have been made and some of its advantages over other indexes are shown.
Not much is known about the chemical composition of low-molecular weight secondary metabolites of Spirodela polyrhiza (L.) Scheiden. We aimed to investigate the composition of low molecular weight volatile organic compounds (VOCs) of S.... more
Not much is known about the chemical composition of low-molecular weight secondary metabolites of Spirodela polyrhiza (L.) Scheiden. We aimed to investigate the composition of low molecular weight volatile organic compounds (VOCs) of S. polyrhiza in the middle of the growing season by GC-MS. A GC-MS analysis of the essential oil of fresh S. polyrhiza was undertaken for the first time. It was found that in the middle of the growing season (in July) the essential oil of S. polyrhiza from a hypertrophic pond (Northwest Russia) contains 89 VOCs, 83 of which were identified. The major low-molecular weight metabolites of S. polyrhiza were manool (25.11%), biformen (12.83%) and phytol (8.05%), which are valuable in practical terms and can play a very important role in aquatic ecosystems. Further study of the composition of VOCs of S. polyrhiza growing in different water bodies and in different conditions (different hydrobiological environments) is necessary to understand the role of this species in hydrobiocenoses. The production of valuable VOCs from S. polyrhiza may be combined with other uses of this plant, e.g., biomass production, the treatment of wastewater with high nutrient concentrations (municipal, industrial and livestock farm wastewater). Large amounts of Lemnaceae biomass and VOCs can be the result of the purification of numerous water bodies that are exposed to duckweed bloom.
The aim of the research was to study a removal of polycyclic aromatic hydrocarbons (PAHs) and phytoextraction of bromine (Br) from contaminated soils. The experiments using pea and wheat seedlings as potential candidates for soil... more
The aim of the research was to study a removal of polycyclic aromatic hydrocarbons (PAHs) and
phytoextraction of bromine (Br) from contaminated soils. The experiments using pea and wheat seedlings
as potential candidates for soil remediation were performed. The soil for the experiments was collected
from a site slightly contaminated by some PAHs. Before planting, the soil was exposed to 20 mg of Br/kg
of soil. In the soil taken from rhizosphere of pea and wheat, the concentrations of many PAHs decreased
up to 7 times compared to the concentrations of the compounds in the initial soil. Pea was capable of
more effectively influencing the soil PAHs than wheat. The growth of pea and wheat in the soil spiked
with Br resulted in a significant increase of Br concentration in a plant. Concentration of Br in roots of pea
and wheat increased 21 and 3 times, respectively. Bromine content in leaves of wheat and pea increased
10 and 4.5 times. This accumulation of Br in the plants led to a decrease of its concentration in the
rhizosphere soil. The experimental results demonstrated a good ability of the plants to cleanup the soils
contaminated with organic and inorganic compounds.
phytoextraction of bromine (Br) from contaminated soils. The experiments using pea and wheat seedlings
as potential candidates for soil remediation were performed. The soil for the experiments was collected
from a site slightly contaminated by some PAHs. Before planting, the soil was exposed to 20 mg of Br/kg
of soil. In the soil taken from rhizosphere of pea and wheat, the concentrations of many PAHs decreased
up to 7 times compared to the concentrations of the compounds in the initial soil. Pea was capable of
more effectively influencing the soil PAHs than wheat. The growth of pea and wheat in the soil spiked
with Br resulted in a significant increase of Br concentration in a plant. Concentration of Br in roots of pea
and wheat increased 21 and 3 times, respectively. Bromine content in leaves of wheat and pea increased
10 and 4.5 times. This accumulation of Br in the plants led to a decrease of its concentration in the
rhizosphere soil. The experimental results demonstrated a good ability of the plants to cleanup the soils
contaminated with organic and inorganic compounds.
⎯The regularities that shape the composition of low molecular weight organic compounds (LMWOCs) in aquatic macrophytes in response to aquatic environment alterations remain poorly characterized. The aim of the present study consists of a... more
⎯The regularities that shape the composition of low molecular weight organic compounds (LMWOCs) in aquatic macrophytes in response to aquatic environment alterations remain poorly characterized. The aim of the present study consists of a comparative interannual investigation into LMWOC composition in rigid hornwort (Ceratophyllum demersum L.) from a Volga-Akhtuba floodplain lake with a variable trophic state. A high variability of LMWOC composition and individual compound levels in hornwort is detected as different trophic states of the water body are analyzed. Active allelochemicals are the predominant LMWOCs in the case of a " macrophytic " mesotrophic state of the lake, with fatty acids (the free fatty acid fraction) apparently being the most important in this group. Hornwort LMWOC composition in the case of a " cyanobacterial " eutrophic type of lake development is characterized by the predomination of compounds that enhance the protective reactions (manool being the most important) under the conditions of suppression by cyanobacteria, which is also manifested as an almost twofold decrease in the overall intensity of organic-compound biosynthesis.
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A gas chromatographic-mass spectrometric analysis of the essential oil of perfoliate pondweed(Potamogeton perfoliatus L.: Potamogetonaceae) from Svirskaja Bay of Lake Ladoga in an early phase of fructification was undertaken for the first... more
A gas chromatographic-mass spectrometric analysis of the essential oil of perfoliate pondweed(Potamogeton perfoliatus L.: Potamogetonaceae) from Svirskaja Bay of Lake Ladoga in an early phase of fructification was undertaken for the first time to identify its qualitative and quantitative composition.Essential oil containing low molecular weight volatile organic compounds (VOCs) was obtained from the dried plants by steam hydrodistillation for 6 hours using a glass Clevenger apparatus. The composition and content of VOCs was analyzed in the hexane extracts using a TRACE DSQ II gas chromatography–mass spectrometer (Thermo Electron Corporation) in a programmed temperature regime with use of decafluorobenzophenone and benzophenone as internal standards. A total of 134 VOCs were detected, 124 of which were identified. Among VOCs of the perfoliate pondweed aldehydes (20,17%) and alcohols (18,32%) prevailed. The major components of the essential oil of P. perfoliatus were (E)-hex-2-enal (10,14%) and manool (6,04%) which are biologically active compounds. Apart from these compounds, a large number of VOCs with diverse biological activity are constituents of component composition of essential oil of the perfoliate pondweed. They may play a part in biotic interactions of P. perfoliatus with other aquatic organisms in the lake ecosystem.
This article deals with the issues of studying low-molecular-weight volatile organic compounds (VOCs) of aquatic macrophytes growing in Russia under different environmental conditions and geographic regions. It is shown that the... more
This article deals with the issues of studying low-molecular-weight volatile organic compounds (VOCs) of aquatic macrophytes growing in Russia under different environmental conditions and geographic regions. It is shown that the composition of VOCs and their content depend on the abiotic (geographical location of habitats, hydrological regime, and light conditions) and biotic factors (season and vegetation phase, distribution in different vegetative organs). Special attention has been paid to the functions performed by VOCs in aquatic ecosystems and their possible use for controlling phytoplankton development and algal “blooms” in inland water bodies.
The role of environmental factors in the formation of zooplankton in tributaries of Lake Ladoga is still poorly investigated. The authors aimed at exploring composition and quantitative patterns of zooplankton development in the major... more
The role of environmental factors in the formation of zooplankton in tributaries of Lake Ladoga is still poorly investigated. The authors aimed at exploring composition and quantitative patterns of zooplankton development in the major tributaries of Ladoga and assessing the impact of environmental factors and features of river catchment basins on the parameters of zooplankton development. A total of 137 taxa ranking below genus were identified (56 species and subspecies of Rotifera, 57 of Cladocera, 24 of Copepoda). Species composition and patterns of quantitative development cannot be explained by any environmental factors or their combination. It is impossible to determine groups of rivers with similar patterns of zooplankton development basing on the composition and abundances of individual zooplankton species. River clustering based on hydrochemical and hydrological parameters and features of catchment basins provides an opportunity to distinguish groups of similar rivers. Total abundances of copepoda, cladocera, and rotifera in the rivers are closely associated with certain combinations of studied physiographic parameters. Physiographic factors, namely, the catchment basin area, water discharge, and lake percentage on the territory of the catchment basin, are the most important in the level of quantitative development of Copepoda, Rotifera, and Cladocera in tributaries of Lake Ladoga.
For the first time, the Baikalian amphipod species Micruropus possolskii Sowinsky, 1915 was recorded in the Shchuchiy Bay of Lake Ladoga in August 2012. The species was probably accidentally introduced into lakes of the Karelian Isthmus... more
For the first time, the Baikalian amphipod species Micruropus possolskii Sowinsky, 1915 was recorded in the Shchuchiy Bay of Lake Ladoga in August 2012. The species was probably accidentally introduced into lakes of the Karelian Isthmus during intentional introduction of the another Baikalian amphipod species Gmelinoides fasciatus (Stebbing, 1899). Later M. possolskii penetrated into Lake Ladoga via different waterways connecting the lakes. The period of M. possolskii penetration into the lake is unknown. It is suggested that the species can spread in the littoral of Lake Ladoga, but mass development of the species is hardly probable.
The composition of detectable small organic compounds in the ethanol extract of Achillea micrantha was defined by means of gas chromatography-mass spectrometric analysis. There were 71 low molecular weight organic compounds observed, two... more
The composition of detectable small organic compounds in the ethanol extract of Achillea micrantha was defined by means of gas chromatography-mass spectrometric analysis. There were 71 low molecular weight organic compounds observed, two of which remained unidentified. The antibacterial activity of the extract was studied in respect to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa using the agar diffusion test and serial dilutions to define minimum inhibitory concentration. In order to compare the antibacterial activity of the herb and blossom truss extract of A. micrantha, the extracts of A. millefolium and A. leptophylla was used. In relation to the microorganisms tested, a significant inhibitory effect was observed with the aqueous alcoholic extract of A. micrantha at the minimum inhibitory concentration of 0.05 µg/ml.
The difference of the evenness index (D E′ ) is offered for an assessment of the ecological state of zoobenthos communities. The index is deduced on the basis of the Shannon indexes calculated according to abundance and biomass data and... more
The difference of the evenness index (D E′ ) is offered for an assessment of the ecological state of zoobenthos communities. The index is deduced on the basis of the Shannon indexes calculated according to abundance and biomass data and differentiates between these informational estimations (Shannon diversity) of evenness of species in any given community. Conclusions made by Pianka about the predomination of organisms with r and K life strategy in communities impacted and unimpacted by ecological stress, as well as the ABC-curves method suggested by Warwick, were used as the basis of the functioning mechanism for the suggested index. The examples of index applicability are demonstrated by an assessment of materials collected in freshwater, estuarine, and marine waterbodies during one-time surveys and long-term monitoring observations. The results are compared with zoobenthos assessments made on the basis of some other indexes. Conclusions concerning the efficiency of the D E′ have been made and some of its advantages over other indexes are shown.