Cyanobacteria, which develop abundantly in aquatic ecosystems, can be harmful to humans and animals not only by releasing toxins that cause poisoning but also by provoking cytogenetic effects. The ...influence of the mass development of cyanobacteria on the genotoxic properties of natural water has been studied in model ecosystems (microcosms) with different compositions of biotic components (zooplankton, amphipods and fish). The validated plant test system "Allium test" was used in this study. Genotoxic effects were detected at microcystin concentrations below those established by the World Health Organization (WHO) for drinking water. In all experimental treatments, cells with disorders such as polyploidy and mitotic abnormalities associated with damage to the mitotic spindle, including c-mitosis, as well as lagging chromosomes were found. Genotoxic effects were associated with the abundance of cyanobacteria, which, in turn, depended on the composition of aquatic organisms in the experimental ecosystem. Fish, to a greater extent than other aquatic animals, maintain an abundance of cyanobacteria. After one month, in microcosms with fish, mitotic abnormalities and polyploidy continued to be detected, whereas in other treatments, there were no statistically significant genotoxic effects. In microcosms with amphipods, the number and biomass of cyanobacteria decreased to the greatest extent, and only one parameter of genotoxic activity (frequency of polyploidy) significantly differed from the control.
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This study aimed to test the hypothesis of the year-round presence of toxigenic
and cyanotoxins in the water and ice of the shallow eutrophic Lake Ytyk-Kyuyol located in the continuous permafrost ...zone. Three independent approaches-mass-spectrometry, molecular methods and light microscopy-were applied in the study. The cyanobacterial biomass ranged from 1.0 × 10
to 4.8 mg L
.
and
were the dominant morphospecies in plankton throughout the observation. In environmental DNA, the presence of
was supported and
gene regions responsible for microcystin biosynthesis were detected through a BLAST (Basic Local Alignment Search Tool) search and phylogenetic estimation based on newly obtained 16S rRNA, 16S-23S ITS rRNA,
A and
E nucleotide sequences. The intracellular microcystin concentration ranged from <0.1 to 803 ng L
, and the microcystin quota in the
biomass was extremely low. For the first time, it was shown that
cells containing
genes and microcystins presented permanently in the water column, both during the ice-free period and under ice, as well as inside thick ice covers within 7 months of severe winter. We hypothesized that minor pelagic and ice populations of
could participate in increasing cell density in the spring. However, further studies are needed to confirm the viability of the overwintering
colonies in the water and inside the ice of Lake Ytyk-Kyuyol.
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In this study, the roles of glutathione (GSH), homoglutathione (hGSH), and their ratio in symbiotic nodule development and functioning, as well as in defense responses accompanying ineffective ...nodulation in pea (
) were investigated. The expression of genes involved in (h)GSH biosynthesis, thiol content, and localization of the reduced form of GSH were analyzed in nodules of wild-type pea plants and mutants
(weak allele, "locked" infection threads, occasional bacterial release, and defense reactions) and
(strong allele, "locked" infection threads, defense reactions), and
(abnormal bacteroids, oxidative stress, early senescence, and defense reactions). The effects of (h)GSH depletion and GSH treatment on nodule number and development were also examined. The GSH:hGSH ratio was found to be higher in nodules than in uninoculated roots in all genotypes analyzed, with the highest value being detected in wild-type nodules. Moreover, it was demonstrated, that a
-to-
switch in gene expression in nodule tissue occurs only after bacterial release and leads to an increase in the GSH:hGSH ratio. Ineffective nodules showed variable GSH:hGSH ratios that correlated with the stage of nodule development. Changes in the levels of both thiols led to the activation of defense responses in nodules. The application of a (h)GSH biosynthesis inhibitor disrupted the nitrogen fixation zone in wild-type nodules, affected symbiosome formation in
mutant nodules, and meristem functioning and infection thread growth in
mutant nodules. An increase in the levels of both thiols following GSH treatment promoted both infection and extension of defense responses in
nodules, whereas a similar increase in
nodules led to the formation of infected cells resembling wild-type nitrogen-fixing cells and the disappearance of an early senescence zone in the base of the nodule. Meanwhile, an increase in hGSH levels in
nodules resulting from GSH treatment manifested as a restriction of infection similar to that seen in untreated
nodules. These findings indicated that a certain level of thiols is required for proper symbiotic nitrogen fixation and that changes in thiol content or the GSH:hGSH ratio are associated with different abnormalities and defense responses.
Diclofenac, an anti-inflammatory drug, is often detected in natural waters in the ng/L to μg/L range, posing a threat to aquatic organisms. The study focused on the effects of diclofenac in a ...gastropod mollusk Radix balthica. A 72-h exposure to environmentally relevant concentrations of diclofenac caused deviations from the baseline activities of the studied enzymes in the digestive gland of snails. Acetylcholinesterase activity was induced by the end of exposure, with the most pronounced increase at 3 μg/L. Results on glutathione-S-transferase activity were nonuniform, and no significant variations were observed in thiobarbituric acid reactive substances concentrations, indicating that diclofenac did not cause oxidative stress in the digestive gland of R. balthica at 0.04–4 μg/L range. Diclofenac lowered the oxygen consumption rate in snails in a concentration-dependent manner. At concentrations ≥0.9 μg/L, animals attempted to switch aquatic respiration to breathing air to regulate their metabolic needs. The study showed that diclofenac at environmentally relevant concentrations affected the fitness of R. balthica.
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•Diclofenac lowered oxygen consumption rate in snails.•At 3 μg/L, diclofenac induced AChE activity in the digestive gland.•No increase in TBARS concentration occurred in response to diclofenac at 0.04–4 μg/L.
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The effects of cyanobacteria (Aphanizomenon flos-aquae (90%), Microcystis aeruginosa) and dense Elodea canadensis beds on the health endpoints of the amphipod Gmelinoides fasciatus and bivalve ...mollusc Unio pictorum were examined in mesocosms with simulated summer conditions (July–August 2018) in the environment of the Rybinsk Reservoir (Volga River Basin, Russia). Four treatments were conducted, including one control and three treatments with influencing factors, cyanobacteria and dense elodea beds (separately and combined). After 20 days of exposure, we evaluated the frequency of malformed and dead embryos in amphipods, heart rate (HR) and its recovery (HRR) after stress tests in molluscs as well as heat tolerance (critical thermal maximum or CTMax) in both amphipods and molluscs. The significant effect, such as elevated number of malformed embryos, was recorded after exposure with cyanobacteria (separately and combined with elodea) and presence of microcystins (MC) in water (0.17 μg/l, 40% of the most toxic MC-LR contribution). This study provided evidence that an elevated number (>5% of the total number per female) of malformed embryos in amphipods showed noticeable toxicity effects in the presence of cyanobacteria. The decreased oxygen under the influence of dense elodea beds led to a decrease in HR (and an increase in HRR) in molluscs. The notable effects on all studied biomarkers, embryo malformation frequency and heat tolerance in the amphipod G. fasciatus, as well as the heat tolerance and heart rate in the mollusc U. pictorum, were found when both factors (elodea and cyanobacteria) were combined. The applied endpoints could be further developed for environmental monitoring, but the obtained results support the importance of the combined use of several biomarkers and species, especially in the case of multi-factor environmental stress.
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•We studied three health biomarkers in animals exposed to cyanobacteria and elodea.•Cyanobacteria led to microcystin appearance and elodea led to oxygen depletion.•Deoxygenation (elodea) affected the mollusc's heart rate and heat tolerance.•Both alone and combined with elodea, cyanobacteria affected amphipod embryos.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
7.
5-Vinyl-1H-tetrazole Krygina, Daria M.; Sivtsov, Eugene V.; Pavlyukova, Yuliya N. ...
MolBank,
03/2023, Volume:
2023, Issue:
1
Journal Article
Peer reviewed
Open access
Highly purified 5-vinyl-1H-tetrazole was synthesized, which is in great demand in modern medicine and industry as a monomer for obtaining nitrogen-rich macromolecular compounds and a reagent for the ...complete synthesis of biological compounds. The molecular structure was studied experimentally with sequential X-ray diffraction analysis and theoretically with ab initio quantum chemical calculations. The data from differential scanning calorimetry, nuclear magnetic resonance (1H, 13C, 1H-15N, HMBC), high-resolution mass spectrometry and vibrational spectroscopy were analyzed. The results are useful for evaluating the possibility of extending the polymerization of 5-vinyl-1H-tetrazole to synthesize polymers with predictable molecular weight and thermodynamic parameters.
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•Immobilization of Ni2+ ions at the inner surface of monodisperse spherical mesoporous SiO2 particles.•Monodisperse spherical mesoporous SiO2/Ni particles of 500±25nm diameter as metal affinity ...sorbents.•Diclofenac extraction by IMAC technique.•Addition of PFOS to IMAC eluents improves the recovery degree of diclofenac (up to 98%).•The obtained thermodynamics analysis data indicate the chemical nature of the DCF interaction with the surface of the sorbent.
In this research, a novel IMAC sorbent with high specificity for chlorine-containing compounds was developed. Ni-functionalized monodisperse spherical mesoporous silica particles of 500±25nm diameter were synthesized and their metal affinity properties were studied with the use of diclofenac as the model substance. The particles were aggregatively stable in the pH range of 3–12. The sorbent demonstrated a high adsorption capacity (0.60±0.06μg of DCF per 1mg of the sorbent) and high adsorption/desorption rate (20 and 5min was enough for the sorbent saturation and desorption of DCF, correspondingly). A mixture of eluents with addition of PFOS providing the almost complete recovery (98%) of diclofenac was first proposed. The monodispersity and the high sedimentation and aggregative stability of the particles provide the formation of a stable hydrosol even under ultrasound treatment which makes the mSiO2/Ni particles suitable for batch chromatography.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This work studies the composition and abundances of phytoplankton and zooplankton and their relationships during cyanobacteria bloom (mainly Dolichospermum lemmermannii) in two subarctic oligotrophic ...lakes, a clear deep lake (Krivoe) and a brown shallow lake (Krugloe). Cyanobacteria bloom (D. lemmermannii) was observed four times during 7–10 days in both lakes: late July, late August, September 2019, and late September 2020. The toxicity of cyanobacteria was determined by the presence of cyanotoxins in water and plankton biomass. Microcystins (mostly LR, RR, and other structure variants) were found in every case of visible blooms (July–September of 2019–2020) in the shallow lake and only once in the deep lake. Despite the nutritious food items (cryptomonads), the presence and dominance of colony-forming microalgae (Botryococcus brauni) and filamentous cyanobacteria in both lakes consisted of a low-efficient food base for grazers. A high abundance of toxic microcystins in the shallow lake with dystrophic features led to the specific composition of zooplankton with the prevalence of the selective grazers, copepod Eudiaptomus graciloides, and cladoceran Ceriodaphnia pulchella adapted to cyanotoxins. In a clear deep lake, where toxic variants of microcystins were low or not detected during the cyanobacteria bloom, the omnivorous rotifer Asplanchna priodonta and small grazer Bosmina longirostris reached high abundance. This study confirms close relationships between cyanobacteria and zooplankton communities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study aimed to test the hypothesis of the year-round presence of toxigenic Microcystis and cyanotoxins in the water and ice of the shallow eutrophic Lake Ytyk-Kyuyol located in the continuous ...permafrost zone. Three independent approaches—mass-spectrometry, molecular methods and light microscopy—were applied in the study. The cyanobacterial biomass ranged from 1.0 × 10sup.−4 to 4.8 mg Lsup.−1 . Microcystis flos-aquae and M. aeruginosa were the dominant morphospecies in plankton throughout the observation. In environmental DNA, the presence of M. aeruginosa was supported and mcy gene regions responsible for microcystin biosynthesis were detected through a BLAST (Basic Local Alignment Search Tool) search and phylogenetic estimation based on newly obtained 16S rRNA, 16S–23S ITS rRNA, mcyA and mcyE nucleotide sequences. The intracellular microcystin concentration ranged from <0.1 to 803 ng Lsup.−1 , and the microcystin quota in the Microcystis biomass was extremely low. For the first time, it was shown that Microcystis cells containing mcy genes and microcystins presented permanently in the water column, both during the ice-free period and under ice, as well as inside thick ice covers within 7 months of severe winter. We hypothesized that minor pelagic and ice populations of Microcystis could participate in increasing cell density in the spring. However, further studies are needed to confirm the viability of the overwintering Microcystis colonies in the water and inside the ice of Lake Ytyk-Kyuyol.
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