Eutrophication caused by the entry of nutrients into a water body may lead to algal bloom. Russia possesses the world’s second highest supply of renewable freshwater resources and has faced the ...problem of eutrophication for many years. Nevertheless, as far as we know, no general analysis of Russia’s algal bloom situation has been before carried out. We have analyzed mass media and scientific reports about algal outbreaks from 2016 to 2018, which allowed us to determine the geographical distribution of algal blooms in Russia, as well as the major effects of eutrophication. As a result, we showed that algal blooms happened in all major climate zones and all federal districts. Cyanobacteria are the most frequently reported photosynthetic organisms comprising algal blooms in freshwater reservoirs located in the continental part of Russia and in the Baltic Sea. Dinoflagellate dominated blooms are more characteristic for the coastal parts of the northeastern Pacific Ocean. The largest number of reports comes from the south of the European part of Russia. However, we did not find significant correlations between state statistics data on factors possibly affecting eutrophication (e.g., population, arable land area, fertilizers, livestock, air temperature, etc.) and the number of algal outbreaks in the regions. Mass media analysis showed that algal blooms attract considerable public attention in Russia, which requires the scientific community to actively participate in solving the problem.
The genome of the moderately haloalkaliphilic diazotrophic anoxygenic phototrophic bacterium Rhodovulum tesquicola A-36sT isolated from an alkaline lake was analyzed and compared to the genomes of ...the closest species Rhodovulum steppense A-20sT and Rhodovulum strictum DSM 11289T. The genomic features of three organisms are quite similar, reflecting their ecological and physiological role of facultative photoheterotrophs. Nevertheless, the nitrogenase activity of the pure cultures of the studied bacteria differed significantly: the highest rate (4066 nmoles C2H2/mg of dry weight per hour) was demonstrated by Rhodovulum strictum while the rates in Rhodovulum tesquicola and Rhodovulum steppense were an order of magnitude lower (278 and 523 nmoles C2H2/mg of dry weight per hour, respectively). This difference can be attributed to the presence of an additional nitrogenase operon found exclusively in R. strictum and to the structural variation in nitrogenase operon in R. tesquicola.
Seven strains of purple nonsulfur bacteria isolated from the shallow-water steppe soda lakes of the cryoarid zone of Central Asia formed a genetically homogeneous group within the genus Rhodovulum. ...The isolates were most closely related to Rhodovulum strictum, from which they differed at the species level (99.5 % 16S rRNA gene identity and 42-44 % DNA-DNA hybridization level). According to genotypic and phenotypic characteristics, the strains were assigned to a new species of the genus Rhodovulum, for which the name Rhodovulum steppense sp. nov. is proposed. Cells of all strains were ovoid to rod-shaped, 0.3-0.8 microm wide and 1-2.5 microm long, and motile by means of polar flagella. They contained internal photosynthetic membranes of the vesicular type and photosynthetic pigments (bacteriochlorophyll a and carotenoids of the spheroidene series). All strains were obligate haloalkaliphiles, growing within a wide range of salinity (0.3-10 %) and pH (7.5-10), with growth optima at 1-5 % NaCl and pH 8.5. Photo- and chemoheterotrophic growth occurred with a number of organic compounds and biotin, thiamine and niacin as growth factors. No anaerobic respiration on nitrite, nitrate or fumarate and no fermentation was demonstrated. Bacteria grew photo- and chemolithoautotrophically with sulfide, sulfur and thiosulfate, oxidizing them to sulfate. Sulfide was oxidized via deposition of extracellular elemental sulfur. No growth with H(2) as electron donor was demonstrated. The major fatty acid was 18 : 1 (81.0 %). The major quinone was Q-10. The DNA G+C content was 66.1 mol% (T(m)). The type strain, A-20s(T) (=VKM B-2489(T) =DSM 21153(T)), was isolated from soda lake Khilganta (Zabaikal'skii Krai, southern Siberia, Russia).
•AlgalTextile (AT) is a new fully organic material for wastewater treatment.•Phosphorus and nitrogen uptake by AT is better than most microbiological methods.•Outlook: seasonal wastewater treatment, ...surface runoff, eutrophic water bodies.•Possible utilization: biofertilizer, anti-desertification agent, biofuel.
Efficient nutrient extraction from wastewater and reuse as bio-fertilizer is an important task for reducing anthropogenic load toward circular economy. Inspired by microbial mats and biofilms, we developed a new material AlgalTextile (AT) that effectively absorbs nutrients from a medium. AT consists of three fully organic components: microalgae, alginate and textile. AT sequestered up to 99% of phosphorus (P-PO4) and 76% of total bound nitrogen from a medium. The uptake rate of phosphorus and nitrogen by AT was highest among all methods using photosynthetic microorganisms, but lower than EBPR and physicochemical methods for phosphorus removal, and anammox and denitrifying bacteria for nitrogen removal. Advantages of AT are its easy production, possibility of seasonal use and utilization as fertilizer. AT as biofertilizer for cress resulted in 35% greater length compared to the control. This outlines a promising technique for seasonal wastewater treatment, improving soil fertility and treatment of polluted surface runoff.
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Two strains of purple non-sulfur bacteria (A-36sT and A-51s) were isolated from brackish steppe soda lakes of southern Siberia. Genetically, the isolates were related most closely to the type strains ...of Rhodovulum steppense and Rhodovulum strictum, from which they differed at the species level (98.5 % 16S rRNA gene sequence similarity, 40–53 % DNA–DNA relatedness). Cells of the two strains were ovoid to rod-shaped, 0.4–0.8 µm wide and 1.0–2.5 µm long, and motile by means of a polar flagellum. They contained internal photosynthetic membranes of vesicular type and photosynthetic pigments (bacteriochlorophyll a and carotenoids of the spheroidene series). The strains were obligate haloalkaliphiles, growing over wide ranges of salinity (0.3–10.0 % NaCl) and pH (7.5–10.0), with growth optima at 1.0–3.0 % NaCl and pH 8.5–9.0. Photoheterotrophic and chemoheterotrophic growth occurred with a number of organic compounds and biotin, p-aminobenzoate, thiamine and niacin as growth factors. No anaerobic respiration on nitrite, nitrate or fumarate and no fermentation were demonstrated. The strains grew photolithoautotrophically and chemolithoautotrophically with sulfide, sulfur and thiosulfate, oxidizing them to sulfate. Sulfide was oxidized via deposition of extracellular elemental sulfur. No growth with H2 as the electron donor was observed. The major fatty acid was C18 : 1 (78 %). The major quinone was ubiquinone Q-10. The DNA G+C content of strain A-36sT was 65.4 mol% (Tm). According to genotypic and phenotypic characteristics, the investigated strains were assigned to a novel species of the genus Rhodovulum, for which the name Rhodovulum tesquicola sp. nov. is proposed. The type strain is A-36sT ( = VKM B-2491T = ATCC BAA-1573T), which was isolated from steppe soda lake Sul’fatnoe (Zabaikal’skii Krai, southern Siberia, Russia).
Here, we report the complete genome sequence (3.97 Mb) of "Halomonas chromatireducens" AGD 8-3, a denitrifying bacterium capable of chromate and selenite reduction under extreme haloalkaline ...conditions. This strain was isolated from soda solonchak soils of the Kulunda steppe, Russian Federation.
Aim
: to evaluate the impact of tissue-engineered structures (TES) transplantation based on mesenchymal stromal cell (MSC) sheets in myocardial infarction on the activation of the epicardial cell ...pool and vascularization of the damaged zone.
Materials and methods
. Mesenchymal stromal cells were obtained from samples of subcutaneous fat of Wistar rats and C57Bl/6 mice. Tissue engineering structures were obtained by culturing cell sheets on thermosensitive plates (Nunc Dishes with UpCell Surface). Transplantation of TESs was performed after myocardial infarction modeling in rats by ligation of the anterior descending coronary artery. Transplant cells and damaged zones were assessed using immunofluorescent staining of myocardial cryosections. The impact of MSC secretion products on the migration activity of epicardial cells in vitro was evaluated using the explant culture method.
Results
. MSCs in TESs after transplantation remain viable and induce activation of the epicardial cell pool and local increase of the damaged zone vascularization. The in vitro experiments showed that the conditioned environment of MSCs stimulates the migratory activity of epicardial cells and initiates the formation of activated Wt1/POD1 precursor cells.
Conclusion
. TES transplantation on the basis of MSC sheets seems to be a promising approach for effective delivery of viable cells into myocardium to activate the epicardial cellular niche and reparative angiogenesis.
Lake Baikal is a UNESCO World Heritage Site and holds 20% of the world's freshwater reserves. On July 26, 2016, a cyanobacterial bloom of a green colour a few kilometers in size with a bad odor was ...discovered by local people in the Barguzinsky Bay on the eastern shore of Lake Baikal. Our study showed very high concentration of chlorophyll a (41.7 g/m3) in the sample of bloom. We found that the bloom was dominated by a nitrogen-fixing heterocystous cyanobacteria of the genus Dolichospermum. The mass accumulation of cyanobacteria in the lake water with an extremely high chlorophyll a concentration can be explained by a combination of several factors: the discharge of biologicaly-available nutrients, including phosphorus, into the water of Lake Baikal; low wind speed and weak water mixing; buoyant cyanobacterial cells on the lake surface, which drifted towards the eastern coast, where the maximum concentration of chlorophyll a was recorded. In the center of the Barguzinsky Bay and in the open part of Lake Baikal, according to satellite data, the chlorophyll a concentration is several orders of magnitude lower than at the shoreline.
The genome of the moderately haloalkaliphilic diazotrophic anoxygenic phototrophic bacterium Rhodovulum tesquicola A-36ssup.T isolated from an alkaline lake was analyzed and compared to the genomes ...of the closest species Rhodovulum steppense A-20ssup.T and Rhodovulum strictum DSM 11289sup.T . The genomic features of three organisms are quite similar, reflecting their ecological and physiological role of facultative photoheterotrophs. Nevertheless, the nitrogenase activity of the pure cultures of the studied bacteria differed significantly: the highest rate (4066 nmoles Csub.2 Hsub.2 /mg of dry weight per hour) was demonstrated by Rhodovulum strictum while the rates in Rhodovulum tesquicola and Rhodovulum steppense were an order of magnitude lower (278 and 523 nmoles Csub.2 Hsub.2 /mg of dry weight per hour, respectively). This difference can be attributed to the presence of an additional nitrogenase operon found exclusively in R. strictum and to the structural variation in nitrogenase operon in R. tesquicola.
During the ongoing coronavirus disease COVID-19 pandemic, many individuals were infected with and have cleared the virus, developing virus-specific antibodies and effector/memory T cells. An ...important unanswered question is what levels of T cell and antibody responses are sufficient to protect from the infection.
In 5340 Moscow residents, we evaluated anti-SARS-CoV-2 IgM/IgG titers and frequencies of the T cells specific to the membrane, nucleocapsid, and spike proteins of SARS-CoV-2, using IFNγ ELISpot assay. Additionally, we evaluated the fractions of virus-specific CD4+ and CD8+ T cells using intracellular staining of IFNγ and IL2 followed by flow cytometry. We analyzed the COVID-19 rates as a function of the assessed antibody and T cell responses, using the Kaplan-Meyer estimator method, for up to 300 days post-inclusion.
We showed that T cell and antibody responses are closely interconnected and are commonly induced concurrently. Magnitudes of both responses inversely correlated with infection probability. Individuals positive for both responses demonstrated the highest levels of protectivity against the SARS-CoV-2 infection. A comparable level of protection was found in individuals with antibody response only, while the T cell response by itself granted only intermediate protection.
We found that the contribution of the virus-specific antibodies to protection against the SARS-CoV-2 infection is more pronounced than that of the T cells. The data on the virus-specific IgG titers may be instructive for making decisions in personalized health care and public anti-COVID-19 policies.
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