Publications by authors named "Denis Grouzdev"

A new filamentous phototrophic bacterium Khr17 was isolated as an enrichment culture from the brackish polar lake Bol'shie Khruslomeny. The organism was a halotolerant, strictly anaerobic phototroph possessing photosystem II. Sulfide was required for phototrophic growth.

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A novel methanotrophic strain 9N was isolated from the sludge of a freshwater lake. Cells were aerobic, Gram-stain-negative, non-motile pleomorphic rods with intracytoplasmic membrane systems that appropriate type-II methanotrophs and hemispherical and spherical exocellular formations on the perimeter of the cell wall surface. The novel isolate grows only on methane or methanol as the sole carbon and energy source, at 10-37 °C (optimum 28-30 °C), pH 4.

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  • The bay scallop (Argopecten irradians) is important commercially, culturally, and ecologically, primarily found on the eastern U.S. coast but also farmed in China.
  • Researchers assembled a detailed chromosome-level reference genome for the bay scallop, with a total size of 845.9 Mb across 1,503 scaffolds and confirmed 16 chromosomes.
  • The genome includes a significant amount of repetitive elements (36.2%), is highly complete (96.2% according to BUSCO analysis), and contains 33,772 protein-coding genes, providing a resource for future evolutionary and conservation studies.
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  • - The hard clam, essential to the U.S. shellfish industry, faced declining populations due to overharvesting, but the shift to aquaculture has led to increased production and new challenges like disease outbreaks.
  • - Researchers developed a 66K SNP array after analyzing a large number of clam samples, which helps in genetic studies, breeding programs, and understanding disease resistance and adaptability to the environment.
  • - The array showed a high performance pass rate and reliability in detecting genetic diversity and relationships among clam populations, including markers for disease management, proving its effectiveness for further research and aquaculture practices.
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Two thermophilic spore-forming sulfate-reducing strains, 435 and 781, were isolated from oil and gas reservoirs in Western Siberia (Russia) about 50 years ago. Both strains were found to be neutrophilic, chemoorganotrophic, anaerobic bacteria, growing at 45-70 °C (optimum, 55-60 °C) and with 0-4.5% (/) NaCl (optimum, 0.

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The tremendous progress in sequencing technologies has made DNA sequencing routine for microbiome studies. Additionally, advances in mass spectrometric techniques have extended conventional proteomics into the field of microbial ecology. However, systematic studies that provide a better understanding of the complementary nature of these 'omics' approaches, particularly for complex environments such as wastewater treatment sludge, are urgently needed.

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  • Ocean acidification (OA) poses a significant threat to marine life, particularly the eastern oyster (C. virginica), and this study investigates how these oysters can withstand OA through molecular mechanisms.
  • Researchers conducted experiments with oyster larvae, comparing the gene expression and genetic variation of individuals raised in normal vs. acidified conditions, revealing significant changes, especially in genes tied to shell formation and immune function.
  • The findings indicate that while short-term acclimation to OA is possible, it may come with sustainability concerns, highlighting the necessity of selecting resilient genetic variants for future oyster conservation and aquaculture efforts.
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A search for the microorganisms responsible for the anaerobic degradation of osmoprotectants in soda lakes resulted in the isolation of a novel halophilic and alkalitolerant strain, designated Z-7514. The cells were Gram-stain-negative and non-endospore-forming rods. Optimal growth occurs at 1.

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The current work deals with genomic analysis, possible ecological functions, and biotechnological potential of two bacterial strains, HO-A22 and SHC 2-14, isolated from unique subsurface environments, the Cheremukhovskoe oil field (Tatarstan, Russia) and nitrate- and radionuclide-contaminated groundwater (Tomsk region, Russia), respectively. New isolates were characterized using polyphasic taxonomy approaches and genomic analysis. The genomes of the strains HO-A22 and SHC 2-14 contain the genes involved in nitrate reduction, hydrocarbon degradation, extracellular polysaccharide synthesis, and heavy metal detoxification, confirming the potential for their application in various environmental biotechnologies.

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The bay scallop, Argopecten irradians, represents a commercially, culturally and ecologically important species found along the United States' Atlantic and Gulf coasts. Since 2019, scallop populations in New York have been suffering large-scale summer mortalities resulting in 90-99% reduction in biomass of adult scallops. Preliminary investigations of these mortality events showed 100% prevalence of an apicomplexan parasite infecting kidney tissues.

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A search for the organisms responsible for anaerobic betaine degradation in soda lakes resulted in isolation of a novel bacterial strain, designated Z-7014. The cells were Gram-stain-negative, non-endospore-forming rods. Growth occurred at 8-52 °C (optimum 40-45 °C), pH 7.

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A spiral-shaped, highly motile bacterium was isolated from freshwater sulfidic sediment. Strain J10 is a facultative autotroph utilizing sulfide, thiosulfate, and sulfur as the electron donors in microoxic conditions. Despite high 16S rRNA gene sequence sequence identity to Magnetospirillum gryphiswaldense MSR-1  (99.

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Studying the minor part of the uncultivated microbial majority ("rare biosphere") is difficult even with modern culture-independent techniques. The enormity of microbial diversity creates particular challenges for investigating low-abundance microbial populations in soils. Strategies for selective sample enrichment to reduce community complexity can aid in studying the rare biosphere.

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Magnetic nanocarriers have attracted attention in translational oncology due to their ability to be employed both for tumor diagnostics and therapy. This review summarizes data on applications of synthetic and biogenic magnetic nanoparticles (MNPs) in oncological theranostics and related areas. The basics of both types of MNPs including synthesis approaches, structure, and physicochemical properties are discussed.

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Two facultatively anaerobic, chemoorganoheterotrophic bacterial strains, designated JR1/69-2-13 and JR1/69-3-13, were isolated from nitrate- and radionuclide-contaminated groundwater (Ozyorsk town, South Urals, Russia). Both strains were found to be motile, Gram-stain negative rod-shaped neutrophilic, psychrotolerant bacteria that grow within the temperature range from 5-10 to 33 °C at 0-3 (0-5)% NaCl (w/v). The major cellular fatty acids were identified as C, C ω7c, C ω7c and C cyclo.

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Anoxygenic photoautotrophic metabolism of green sulfur bacteria of the family Chlorobiaceae played a significant role in establishing the Earth's biosphere. Two known major ecological forms of these phototrophs differ in their pigment composition and, therefore, in color: the green and brown forms. The latter form often occurs in low-light environments and is specialized to harvest blue light, which can penetrate to the greatest depth in the water column.

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Magnetosome synthesis in magnetotactic bacteria (MTB) is regarded as a very ancient evolutionary process that dates back to deep-branching phyla. Magnetotactic bacteria belonging to one of such phyla, , contain the classical genes for the magnetosome synthesis (e.g.

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Biomimetic nanomaterials (BNMs) are functional materials containing nanoscale components and having structural and technological similarities to natural (biogenic) prototypes. Despite the fact that biomimetic approaches in materials technology have been used since the second half of the 20th century, BNMs are still at the forefront of materials science. This review considered a general classification of such nanomaterials according to the characteristic features of natural analogues that are reproduced in the preparation of BNMs, including biomimetic structure, biomimetic synthesis, and the inclusion of biogenic components.

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The goal of the present work was to determine the diversity of prokaryotes involved in anaerobic oil degradation in oil fields. The composition of the anaerobic oil-degrading methanogenic enrichment obtained from an oil reservoir was determined by 16S rRNA-based survey, and the facultatively anaerobic chemoorganotrophic bacterial strain HO-Ch2 was isolated and studied using polyphasic taxonomy approach and genome sequencing. The strain HO-Ch2 grew optimally at 28 °C, pH 8.

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A novel species is proposed for a high-affinity methanotrophic representative of the genus . Strain FS was isolated from a weakly acidic (pH 5.3) mixed forest soil of the southern Moscow area.

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In this study, the magnetic properties of magnetosomes isolated from lyophilized magnetotactic bacteria SO-1 were assessed for the first time. The shape and size of magnetosomes and cell fragments were studied by electron microscopy and dynamic light scattering techniques. Phase and elemental composition were analyzed by X-ray and electron diffraction and Raman spectroscopy.

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Article Synopsis
  • Seawater injection for secondary oil recovery in the Uzen oil field leads to the growth of sulfidogenic bacteria, causing issues like corrosion of steel equipment, oil souring, and environmental damage.
  • The study used techniques like 16S rRNA sequencing and scanning electron microscopy to analyze microbial populations and how to inhibit harmful bacteria in both free-floating and biofilm forms.
  • Key findings showed that different types of bacteria thrived in various conditions influenced by temperature and seawater, including methanogens and sulfate-reducing bacteria, which have significant effects on the oil field's microbial ecosystem.
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A novel, aerobic nitrogen-fixing methylotrophic bacterium, strain 29k, was enriched and isolated from sludge generated during wastewater treatment at a paper mill in Baikal, Russian Federation. Cells were Gram-stain-variable. The cell wall was of the negative Gram-type.

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