In this work, using coarse-grained molecular modeling methods, the interactions of DNA-binding protein from starved cells (Dps) of the bacterium Escherichia coli with DNA sections of various lengths and composition are investigated. The binding features in two-dimensional crystals of the Dps protein are studied. Using free energy search methods—thermodynamic integration and linear interaction energy—the most favorable conditions for the binding of DNA and Dps are determined.

The peculiarities of the process of forming complex compounds, namely, spinels, in flux-cored arc welding for the slag TiO2-MnO-SiO2-MgO-CaO-FeO-Al2O3 system are studied.An experimental investigation of the mechanism of spinel formation in conditions of electrode arc welding and cladding under flux is carried out.Based on the analysis of microimages of the slag surface obtained using scanning electron microscopy, the mechanism of spinel formation, namely, the growth of microcomplex compounds into macrospinels, is presented.The main stages and mechanism of formation of the complex compounds, namely, spinels, are described.As shown, the structure of spinels is determined by the temperature conditions of the crystallization of the slag melt.The study reveals that one of the determining factors of high-temperature separation of the slag crust during multilayer cladding with overlap of the previous layer is the formation of spinels at the interphase boundary between the slag and the metal.Based on modern ideas about the structure of slag melts, a mechanism for the formation of complex compounds at the interphase boundary between slag and metal is proposed.The main factor determining the process of high-temperature separation of the slag coating for the TiO2-MnO-SiO2-MgO-CaO-FeO-Al2O3 system is the formation of complex compounds based on spinel-forming elements and slag oxides at the interphase boundary between the slag and the metal.

Державний контроль та нагляд у сфері епізоотичного благополуччя забезпечує гарантії щодо безпеки продуктів тваринного походження, харчових продуктів рослинного походження, призначених для споживання людьми, а також кормів для годівлі тварин. Головними управліннями територіальних органів Держпродспоживслужби України щорічно розробляються «Плани протиепізоотичних заходів по профілактиці основних інфекційних і паразитарних хвороб тварин в Україні» що дає змогу чітко контролювати розвиток епізоотичного процесу. У статті проведено порівняльний аналіз динаміки епізоотичного процесу щодо ураження бджіл кліщем вароа в Україні з 2021 по 2023 рр. Наведено дані в розрізі областей. Визначено зони ризику з умовним поділом України на неблагополучну, загрозливу та тимчасово благополучну території.

The structural organization of DNA in stressed (with increased stress resistance), anabiotic, and mummified cells obtained by introducing 4-hexylresorcinol in different concentrations at different stages of cell culture growth is studied using the synchrotron radiation diffraction technique. The experimental studies allow us to conclude that 4-hexylresorcinol is the initiator of the transition of cells into an anabiotic and mummified state in the stationary stage of growth. In the prestationary stage, in the studied concentration range, 4-hexylresorcinol initiates the transition of cells into a mummified state but not into an anabiotic state, which indicates that DNA is unprepared for the crystallization process in these bacteria. The structure of DNA inside a cell in an anabiotic dormant state (the almost complete absence of metabolism) and dormant state (starvation stress) coincide (form nanocrystalline structures). The data indicate the universality of DNA condensation or the universality of DNA protection by the Dps protein in the dormant state, regardless of the type of stress. The mummified state (the complete absence of metabolism, irreversible to life) is very different in structure (has no order within the cell).

The architecture of DNA in the dormant cells was studied by synchrotron radiation diffraction and transmission electron microscopy. Diffraction experiments indicate the appearance of a periodic ordered organization of DNA. Transmission electron microscopy made it possible to visualize information about the type of DNA condensation. Intracellular nanocrystalline, liquid-crystalline and folded nucleosome-like structures of DNA have been found. Next, we studied changes in DNA architecture under stress of exposure to a chemical analogue of the anabiosis autoinducer (4-hexylresorcinol). Studies of the DNA architecture in the anabiotic and mummified states show the identity of the DNA structure in the anabiotic state and in the dormant state under starvation stress. The architecture of DNA in a mummified state is very different from that of DNA in an anabiotic state.

The use of disinfectants is a crucial aspect of preventive and health improvement measures for infectious diseases in farm and domestic animals. Regulatory documents require the determination of toxicity to macroorganisms, including the establishment of lethal doses and toxicity groups, during the development and registration of antimicrobial agents. This study aimed to investigate the histological changes in the internal organs of laboratory animals when determining lethal doses of innovative disinfectants. The experiments used domestic disinfectants containing glutaraldehyde as the active ingredient. Histological studies were conducted on the internal organs (kidney, liver, stomach, intestines, and spleen) of 75 laboratory animals using an Axioskop 40/40FL microscope (Carl Zeiss, Germany) with video microscopic photography. The methods used were under current standards. Hemodynamic disorders were observed in the renal tissue under the influence of lethal doses of aldehyde disinfectants. These disorders were characterized by capillary dilation and blood filling. Glomerular capillary dilation and overflow with blood cells were also detected. Additionally, stasis was observed in the lumen of the microcirculatory vessels throughout the entire length. The examination of histological sections from animal liver samples revealed a significant expansion of Dissé spaces, variations in the size of hepatocyte nuclei, beam decomposition and fragmentation, small acute perivascular hemorrhages, leukostasis in sinusoids, and hemodynamic disorders. The structure of the organ's beams was also disturbed, and a significant number of venous vessels were dilated and excessively filled with blood cells. Minor changes were detected in the stomach, including desquamation of the epithelial cells of the glands and their exfoliation into the gastric lumen, as well as circulatory disorders. Epithelial desquamation, blood vessel dilation, and signs of connective tissue edema were observed in the intestine. The kidneys exhibited signs of acute venous hemorrhage and stasis in vessels of various calibers, with the development of small acute parenchymal hemorrhages and localized lymphoid cell death in the white pulp. The prospect of further research is to investigate the histomorphological changes in the internal organs of laboratory animals when exposed to modern complex disinfectants with different active ingredients.

У сучасних умовах розвитку промислового птахівництва, розробленню нових біологічних профілактич-них препаратів для корекції мікробіоценозу та підвищення неспецифічного імунітету птиці надаєтьсяпріоритетне значення. В матеріалах статті представлені результатами досліджень антагоністичнихвластивостей 5 ізолятів Enterococcus faecium, виділених із сліпих відростків товстого кишечника з вмістом,відібраного від курей та курчат-бройлерів із птахогосподарств України за проведення активногомоніторингу згідно державної програми з Порядку проведення нагляду (активного моніторингу) запротимікробною резистентністю зоонозних та коменсальних бактерій у ветеринарній медицині таідентифікованих до виду. Дослідження були виконані двома дифузійними методами – відтермінованогоантагонізму та агарових блоків з метою підтвердження достовірності одержаних результатів. Встановленоу 2 штамів Enterococcus faecium – Efm-3 і Efm-5 дуже високий та високий рівні антагонізму після взаємодіїштамів з грамнегативними і грампозитивними тестовими бактеріями E. coli АТСС 25922 (діаметри зонінгібування росту 39,4±1,3/36,4±0,3 і 42,2±2,7/39,4±2,7 мм відповідно до штамів і методів), P. aeruginosaАТСС 15442 (29,0±1,3/28,4±0,7 і 29,2±1,3/39,4±2,7), S. typhimurium АТСС 29630 (17,2±0,7/17,2±1,7 і28,2±0,7/28,6±0,7) і S. aureus АТСС 6538 (28,2±0,07/28,4±0,7 і 35,2±0,7/34,2±0,17), які знаходяться вдіапазоні значень високого антагонізму. Штами Efm-3 і E fm-5 Enterococcus faecium відібрано в якостіперспективних пробіотичних мікроорганізмів, завдячуючи авірулентним властивостям та показникамвисокого рівня антагоністичної активності. Одержані дані засвідчують можливість корекції імунноївідповіді за допомогою розроблених комплексних пробіотичних препаратів у складі з відібранимиперспективними штамами Enterococcus faecium, направлених на нормалізацію мікрофлори кишечника,посилення імунних функцій організму, підвищення показників збереженості птиці та якості одержаноїпродукції.

In the article reviewed and discussed literature data on biological properties of nanomaterials. The biosafety of nanomaterials is a complex and multifaceted issue that demands a comprehensive, science-based approach. Modern environmental and economic factors should be considered in this regard. The EU’s nanotechnology policy is based on ‘an integrated, safe and responsible approach’ (Communication from the Commission to the European Parliament, the Council and the European Economic and Social Committee. Regulatory aspects of nanomaterials. SEC(2008) 2036 / COM(2008) 366 final). Based on the findings of toxicity and antimicrobial activity studies, metal nanoparticles appear to be a favorable choice as antibacterial agents in developing new disinfectants. However, further measures must be taken to ensure the safe and environmentally friendly use of metal nanoparticles (MeNPs). To achieve this, it is crucial to establish toxicity parameters for MeNPs of various compositions, sizes, and concentrations. These parameters must be compared and evaluated alongside the potential effects of MeNPs on laboratory and target animals (in vivo), as well as their antibacterial performance against microorganisms of different strains (in vitro). Thus, the investigation of possible hazards associated with the use of metal nanoparticles can be effectively achieved by analyzing the fundamental systemic characteristics of biological systems under both in vivo and in vitro conditions, taking into account various aspects such as physiological, biochemical, immunological, genetic and cytological responses that may be affected by toxic effects. The literary sources analysis and article publication were conducted under the National Research Foundation of Ukraine project No. 2021.01/0076 'Development of a novel, nanoparticle-based disinfectant for deactivation of pathogens causing emergent infectious diseases'

— Adaptive mechanisms allow bacteria to survive even under extreme desiccation, which they face both in the natural environment and in biotechnological processes. The DNA-binding protein Dps plays an important role in this process. In the present work, we revealed the protective properties of the Dps protein under desiccation stress to depend on both the cultivation temperature and the temperature of the subsequent desiccation process. The experimental data obtained were successfully predicted by the calculations performed using modern classical molecular dynamics methods. The results of the study are important for applications in biotechnological production and microbial collections.

In this study, molecular modeling is used to study the interaction of the autoregulatory factor of bacteria, a chemical analog of the inducers of anabiosis of 4-hexylresorcinol (4HR), with the outer and inner membranes, the porin protein, peptidoglycan, DNA, and the DNA stabilizing protein Dps of the Escherichia coli ( E. coli ) bacterium. The concentration dependence and molecular mechanisms of the interaction of 4HR with cell polymers are studied by molecular dynamics in the full-atomic approximation. The spatial and energy characteristics of 4HR complexes with various cellular components are obtained. Using principal component analysis, the characteristics of DNA and the DNA-binding Dps protein are determined under conditions of various 4HR complexes. The obtained results, which are consistent with the experimental data, allow a deeper understanding of the processes that occur during the protection of the bacterial cell at the level of the envelope and the preservation of DNA by nucleoid proteins.

У публікації наведені результати дослідження токсичності та віруліцидної дії нового дезінфікуючого засобу «Йодосан», основною діючою речовиною якого є йод. Вивчення проводили відповідно до національних і міжнародних керівництв щодо характеристики віруліцидних властивостей нових дезінфікуючих засобів. Вивчення токсичності дезінфікуючого засобу «Йодосан» проводили за умов білкового навантаження на моделі культури клітин BHK-21/ С13. Визначення віруліцидної активності дезінфікуючого засобу «Йодосан» проводили за умов білкового навантаження на моделі оболонкового вірусу сказу (штам CVS-11). Токсичність дезінфікуючого препарату «Йодосан» визначали для 0.1 %; 0.2 %;0.3 %; 0.5 %; 1.0 % та 2.0 % концентрацій за експозиції 30 та 60 хв відповідно. Віруліцидну дію дезінфікуючого засобу «Йодосан» визначали для 0.1 %; 0.2 %; 0.3 %; 0.5 % та 1.0 % концентрацій відносно робочих розведень суспензій вірусу сказу – 5,5 TCID50/ml. Результати дослідження показали, що дезінфікуючий засіб «Йодосан» є нетоксичним для культур перещеплюваних клітин у концентраціях 0.1 %;0.2 %; 0.3 %; 0.5 % та 1.0 %. Дезінфікуючий засіб діє 100 % віруліцидно відносно оболонкового вірусу сказу (штам CVS-11) у концентраціях 0.2 %; 0.3 %; 0.5 % та 1.0 % відповідно за експозиції 30 та 60 хв за білкового навантаження, що свідчить про високу віруліцидну активність дезінфікуючого засобу «Йодосан».

The purpose of the work was to study changes in the morphological and biochemical parameters of the blood of 50-day-old piglets spontaneously infested with Eimeria and Balantidia. An experimental group of animals spontaneously infested with Eimeria and Balantidia and a control group (n=5) not infested were formed. To examine feces for the presence of Eimeria, the McMaster method in Raynaud's modification, Balantidia - native smear was used. Changes in morphological and biochemical indicators of blood during the mixed course of eimeriosis and balantidiosis were determined. In the blood of piglets infected with Eimeria and Balantidia, a decrease in the hemoglobin content by 10.4% and the number of erythrocytes by 17.0% was established. At the same time, the number of leukocytes increased by 22%. In the leukogram, the percentage of eosinophils increased by 40.0%, rod- and segmented-nuclear neutrophils by 26.3% and 2.1%, respectively. The number of monocytes increased by 35.3%, which indicates the appearance of foci of inflammation in the animal's body. An increase in the leukocyte index of intoxication by 11.1% indicates the severity of the inflammatory process. In infected piglets, a decrease in total protein content by 6.5% due to a significant decrease in albumin content by 28.3% was recorded. An increase in the concentration of CIC by 23.5%, the activity of the enzymes AlAT and AsAT by 75.4% and 35.9%, respectively, confirms the development of the pathological process and the occurrence of accompanying structural and functional changes in the internal organs of piglets. During the mixed course of eimeriosis and balantidiosis in 50-day-old piglets, leukocytosis and eosinophilia, an increase in the number of rod-shaped and segmented neutrophils, lymphopenia and monocytosis are observed. Changes in indicators indicate an exacerbation of the inflammatory process in the body of infected piglets and a toxic effect in the places of parasitism - the small and large intestines. In the biochemical composition of the blood serum of piglets with the development of the disease, there is a decrease in the content of total protein and albumins, which is associated with a violation of the biloxintizing function of the liver, and an increase in β-globulins indicates a suppression of the immune response to invasion. An increase in the activity of AlAT and AsAT enzymes indicates the development of dystrophic processes in the liver, which plays a primary role in the neutralization of toxins produced in the body of animals. An increase in the concentration of CIC indicates the gradual development of the immune response to the course of the disease

Based on the analysis of OIE data and world scientific literature, the spread of spumavirus infection and bovine immunodeficiency in livestock production worldwide, and on the basis of our own research in Ukrainian livestock production was studied. The adaptive ability of field isolates of minor infections to homologous cell cultures for cattle, genetic characteristics of pathogens isolated in different regions of Ukraine, the effect of field isolates of the pathogen when inoculated into the body of laboratory animal models at the hematological, molecular genetic and biochemical levels have been studied

Deoxyribonucleic acid (DNA) is organized hierarchically in the nucleoid of an actively growing cell, with three levels of DNA compaction. The lower level (small scale ≥1 kb base pairs (bps)) is provided by the interaction with DNA-bound proteins. Actively growing cells maintain a dynamic, far from equilibrium order through metabolism. When cells enter a dormant state (almost complete absence of metabolism), the usual biochemical methods of protecting DNA cease to work, and the cells, adapting to the new conditions, are forced to use the physical mechanisms of DNA protection. The structure of DNA in the nucleoid of dormant cells formed during starvation stress is studied using synchrotron radiation diffraction and transmission electron microscopy (TEM). The experimental results make it possible to visualize the structures of the lower hierarchical level of DNA compaction in the nucleoid of dormant cells. A series of diffraction experiments conducted for the first time indicate the presence of a periodic ordered organization of DNA in all the studied bacteria . The TEM method made it possible to extract fine visual information about the type of DNA condensation in the nucleoid of the bacterium Escherichia coli ( E. coli ). Intracellular nanocrystalline, as well as liquid-crystalline and folded nucleosome-like, structures of DNA are found. The folded nucleosome-like structure was observed for the first time and is the result of the multiple folding of long DNA molecules around the DNA-binding protein (Dps) of starved cells and its associates. The different types of condensed state of DNA found by us in the studied dormant E. coli cells (DNA condensation heterogeneity) provide additional arguments in favor of the concept that considers a microbial population as a multicellular organism. The study of changes in the DNA architecture under the effect of the chemical analog of the autoinducer of anabiosis 4-hexylresorcinol (4-HR) is studied. An increase in the 4-HR concentration induces the transition of a part of the cells of the population to anabiotic dormant state, and then to a mummified state. The studies of the structure of DNA in the anabiotic and mummified states show the spectroscopic identity of the DNA structure in the dormant anabiotic state and in the dormant state formed during starvation stress. Studies of the structure of DNA in the mummified state show a strong difference from the structure of DNA in the anabiotic state.

Методом молекулярного моделирования проводится исследование взаимодействия ауторегуляторного фактора бактерий, химического аналога индукторов анабиоза 4-гексилрезорцина (4ГР), с наружной и внутренней мембранами, белком порином, пептидогликаном, ДНК и стабилизирующим ДНК белком Dps бактерии Escherichia coli . Методами молекулярной динамики в полноатомном приближении исследованы концентрационная зависимость и молекулярные механизмы взаимодействия 4ГР с полимерами клетки. Получены пространственные и энергетические характеристики комплексов 4ГР с различными клеточными компонентами. С помощью анализа главных компонент определены характеристики ДНК и белка Dps, связывающего ДНК, в условиях различного содержания 4ГР. Полученные результаты, согласующиеся с экспериментальными данными, позволяют глубже понять процессы, происходящие при защите бактериальной клетки на уровне оболочки и сохранения ДНК нуклеоидными белками.

The development of organic livestock farming, in particular poultry farming, which Ukraine is targeting, requires a radical change in approaches to the prevention and treatment of infectious diseases. The macroorganism and microbiota of the gastrointestinal tract constitute a single ecological system with homeostatic balance. However, its violation creates a threat of an imbalance of intestinal normal flora and the development of diseases of bacterial etiology in poultry. Considering this, there is a growing need for the development and use of probiotic preparations. The high antagonistic potential of bacteria of the genus Bacillus in relation to other pathogens causes scientific and industrial interest in the development of probiotics with their involvement in the composition of these bacteria as an alternative to antibiotics. But due to the existence of risks of direct transfer of R-plasmids of antibiotic resistance to the biotic microflora of the gastrointestinal tract together with probiotic strains when they acquire resistance, promising strains of bacteria of the genus Bacillus should be tested for sensitivity to antibiotic drugs. We selected promising probiotic strains with a high level of antagonism, Bacillus subtilis Bs-5 and Bs-9, Bacillus licheniformis Bfl-1 and Bfl-4, Bacillus coagulans Bcg-5, Bacillus amyloliquefaciens Baf-1 and Baf-3 showed full sensitivity to the applied antibiotics — representatives of the groups of carbapenems, fluoroquinolones, glycopeptides, lincosamides, macroliths and oxazolidones. These strains were recommended as probiotic, antibiotic sensitive, safe and promising for their use in the design of probiotic preparations. The obtained results of laboratory studies of other strains of B. subtilis, B. licheniformis, B. coagulans, B. amyloliquefaciens proved the presence among them of bacteria polyresistant to fluoroquinolone, carbapenem, macrolide and glycopeptide antibiotics.

Дезоксирибонуклеиновая кислота (ДНК) организована в нуклеоиде активно растущей клетки иерархически – с тремя уровнями компактизации ДНК. Нижний уровень (малый масштаб ≥1 Кбайт пар оснований) обеспечивается взаимодействием со связанными с ДНК белками. Активно растущие клетки поддерживают динамический, далекий от равновесия порядок благодаря метаболизму. При переходе клеток в покоящееся состояние (практически полное отсутствие метаболизма) обычные биохимические способы защиты ДНК перестают работать, и клетки, адаптируясь к новым условиям, вынуждены использовать физические механизмы защиты ДНК. Проведено изучение структуры ДНК в нуклеоиде покоящихся клеток, образующихся при стрессе голодания, с помощью методов дифракции синхротронного излучения и просвечивающей электронной микроскопии ( ПЭМ ). Экспериментальные результаты позволили визуализировать структуры нижнего иерархического уровня компактизации ДНК в нуклеоиде покоящихся клеток. Впервые проведенная серия дифракционных экспериментов свидетельствует о наличии периодической упорядоченной организации ДНК во всех изученных бактериях . Метод ПЭМ позволил извлечь тонкую визуальную информацию о типе конденсации ДНК в нуклеоиде бактерии Escherichia coli ( E. coli ). Обнаружены внутриклеточные нанокристаллические, жидкокристаллические и свернутые нуклеосомоподобные структуры ДНК. Свернутая нуклеосомоподобная структура наблюдалась впервые, она является результатом множественного сворачивания длинных молекул ДНК вокруг связывающего ДНК белка голодающих клеток (Dps) и его ассоциатов. Обнаруженные нами различные типы конденсированного состояния ДНК в изучаемых покоящихся клетках E. сoli (гетерогенность конденсации ДНК) дают дополнительные аргументы в пользу концепции, рассматривающей микробную популяцию как многоклеточный организм. Проведено изучение изменений в архитектуре ДНК под влиянием химического аналога аутоиндуктора анабиоза 4-гексилрезорцина (4-ГР). Рост концентрации 4-ГР индуцирует переход части клеток популяции в анабиотическое покоящееся состояние, а затем – и в мумифицированное состояние. Проведенные исследования структуры ДНК в анабиотическом и мумифицированном состояниях показывают спектроскопическую идентичность структуры ДНК в покоящемся анабиотическом состоянии и в покоящемся состоянии, образующемся при стрессе голодания. Исследования структуры ДНК в мумифицированном состоянии показывают сильное отличие последней от структуры ДНК в анабиотическом состоянии.

Nowadays it is important to develop new disinfectants for poultry which are simple in use, non-toxic if used in the presence of birds, with a broad bactericidal spectrum, not causing the resistance of microflora, maintaining the air environment, linking ammonia and deodorizing the air. One of the product effectiveness indicators comes from testing on micromycetes which are persistent on the indoor surfaces and require high fungicidal concentrations of active substances. Research results of the effect produced by the “Diolide” disinfectant with 42% sodium chlorite and 46% sodium chloride base showed fungicidal activity against the etalon strains of Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404. By serial digestion method using paper disks on Chapek’s medium and on the malt agar in the presence of the “Diolide” disinfectant the effective concentration of 0.1% was established. “Diolide” disinfectant at 0.1% concentration at 60 min. exposure completely disinfected test objects of wood, iron, brick and plaster which were contaminated with micromycetes. It was found that the effectiveness of “Diolide” disinfectant depends directly on the time of exposure and it is therefore necessary to adhere to these conditions in the production process.

Control of feed contamination by micromycetes and bacteria at all stages of their preparation, storage, and feeding of farm animals is an acute issue of feed safety and one of the principal measures that create an opportunity to prevent their negative impact on animal health. Therefore, the study aimed to investigate the state of metabolic processes in cattle of different physiological groups under the influence of biotic feed contaminants. The material for the research was grain fodder and coarse grinding grain of local production, roughage used on the farm. Veterinary and sanitary condition of grain products was established based on organoleptic, toxico-biological and microbiological studies. To determine the indicators of the state of metabolic processes, 3 groups of cows (n = 5–7) with different physiological conditions were formed: group I — non-pregnant cows, group II — pregnant animals with normal pregnancy, group III — cows after miscarriage. Biochemical parameters (level of total protein, albumin, globulins, vitamins A and E) in blood serum samples were determined spectrophotometrically by conventional methods. The study of the content of inorganic elements in the aggregate samples of bovine sera was performed using an X-ray spectrometer ‘Spectroscan MAX’. Laboratory studies have proven the presence of biotic contaminants in the feed base of the experimental farm. Exceedance of maximum permissible levels of feed contamination (max 16.50×104 CFU/g when MPL 5.0×104 CFU/g) by toxin-forming micromycetes (due to the genera Fusarium, Aspergillus, Penicillium, Mucor, and Rhizopus; a total of 24 isolates of microscopic fungi were isolated, which showed high toxicity in 11.3% and weak — in 20.1% of samples) and total bacterial contamination (max 18.7×105 CFU/g when MPL 5.0×105 CFU/g), in the structure of which coliform bacteria and Salmonella enterica were isolated. In cattle that consumed feed with an excess of biotic contaminants, disorders of the digestive tract (diarrhea) and reproductive capacity (abortions in the first half of pregnancy) were observed and metabolic disorders were found in cattle: increased Iron (on average 1.5 times) and Bromine (on average 1.6 times) levels, a decrease in the concentration of vitamin A (by 17.4–39.8%), and vitamin E (by 10.0–12.5%), most pronounced in cows after abortion and pregnant cows, respectively, Manganese (on average by 12.5%) and Selenium (by 30.7%)

The three-dimensional (3D) architecture of the genome determines cell function. The study of DNA condensation in the cell is important for understanding the mechanisms of bacterial survival and for medicine, since ordered DNA condensation provides antibiotic resistance to pathogenic bacteria . In a dilute solution, the length of DNA is several centimeters. The length of an Escherichia coli bacterium is approximately 2.0 μm. Such a dramatic decrease in the volume occupied by DNA is a consequence of its condensation. It was found that DNA is hierarchically organized in the nucleoid with three levels of DNA compaction: the lowest level (small scale ≥1 kb bp) is provided by histone-like NAP proteins. Unlike actively growing bacteria, bacteria under starvation stress use an energy-independent mechanism to maintain the order and protect vital structures (DNA), as in inanimate nature. The study of the DNA structure in the nucleoid of E. coli bacterium was carried out using synchrotron X-ray diffraction and transmission electron microscopy. The experimental results allowed visualization of the structures of the lowest hierarchical level of DNA compaction in the nucleoid of dormant cells. The series of diffraction experiments performed for the first time indicates the presence of a periodic ordered organization of DNA in all studied bacteria. The transmission electron microscopy provided more subtle visual information about the type of DNA condensation in the nucleoid of E. coli bacterium. Intracellular nanocrystalline, liquid-crystalline, and folded nucleosome-like structures of DNA were found. A folded nucleosome-like structure was observed for the first time, it is a result of multiple folding of long DNA molecules around Dps protein and its associates.