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Luminous marine bacteria are traditionally used as a bioassay due to the convenience and high rate of registering the intensity of their physiological function - luminescence. This study aimed to develop the application of Photobacterium phosphoreum in traditional and novel fields - toxicity monitoring and biotechnology. We demonstrated (1) effects of selenite ions on bioluminescence, and (2) biotransformation of selenite to selenium(0) in the form of nanoparticles. The effects of selenite (SeO 3 ) on the intensity of bacterial bioluminescence were studied, and its dependencies on exposure time and concentration of Na 2- ) on the intensity of bacterial bioluminescence were studied, and its dependencies on exposure time and concentration of Na 2 were analyzed. Bioluminescence activation and inhibition were revealed; dose-effect dependencies corresponded to the hormesis model. The toxicity of SeO 3 was characterized by an effective concentration of 10 3 M. Effects of SeO 2- on reactive oxygen species (ROS) in bacterial suspensions were studied. High positive correlations were found between the bioluminescence intensity and ROS content, which indicates the decisive role of ROS and associated redox processes in the bioeffects of selenite ions. Scanning and transmission electron microscopy revealed the presence of nano-structures in the bacteria exposed to selenite. The energy dispersion spectrum detected a high content of selenium in the nanoparticles. The particle size distribution depended on Na -3 M. Effects of SeO 3 concentration; maxima of the distribution varied within 45-55 nm.2- on reactive oxygen species (ROS) in bacterial suspensions were studied. High positive correlations were found between the bioluminescence intensity and ROS content, which indicates the decisive role of ROS and associated redox processes in the bioeffects of selenite ions. Scanning and transmission electron microscopy revealed the presence of nano-structures in the bacteria exposed to selenite. The energy dispersion spectrum detected a high content of selenium in the nanoparticles. The particle size distribution depended on Na 2 SeO 3 concentration; maxima of the distribution varied within 45-55 nm., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Nadezhda S. Kudryasheva reports financial support was provided by Russian Science Foundation and Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rapid and accurate monitoring of residual antibiotic concentrations is of great importance in environmental monitoring. Therefore, research is active to develop new methods for analyzing antibiotics. Biosensors, including those based on nanozymes, are very successful for antibiotic analysis. Nanozymes (nanomaterials with enzymelike activity) have emerged as a promising solution offering improved stability, cost-effectiveness, and versatility, as compared with natural enzymes. The use of nanozyme-based electrochemical and colorimetric sensors for detecting antibiotics remains underexplored. This review presents the main prospects for the use of electrochemical and colorimetric nanozyme sensor systems to detect antibiotics. It identifies major shortcomings of these platforms and ways to deal with them. Finally, it highlights the advantages of these sensors over other systems and explains the main mechanisms of signal generation for antibiotic detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Levan-type polysaccharides, produced by various organisms, are nontoxic, biocompatible, and biodegradable polymers with a wide range of biological activities. They have high potential for use in medicine, cosmetology, and industry. A large amount of levan (41.1 g L -1 ) was recovered by ethanol precipitation from a liquid nutrient medium of Paenibacillus polymyxa 88A that contained 15 % w/v sucrose as a carbon source. The levan was fractionated by gel-permeation and anion-exchange chromatography and was analyzed by DRIFT and NMR spectroscopy. It was found that levan was represented by slightly branched chains composed of β-(2→6)-Fruf residues. The average molecular mass of the levan was about 1.9 MDa. When shear stress was applied at different temperatures, aqueous levan solutions showed pseudoplastic behavior. As found by SEM, a freeze-dried powdered levan sample had a microporous structure. The levan had excellent emulsifying activity toward sunflower oil, forming an emulsion with long-term stability. Analysis of the antioxidant activity of the levan showed a higher, dose-dependent activity toward ABTS, as compared with that toward DPPH. Finally, the bioactivity of the levan was examined by MTT assay by using human cervical carcinoma (HeLa) cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microbial reduction of selenium oxyanions, highly soluble, mobile and toxic inorganic selenium compounds, to insoluble selenium nanoparticles (Se NPs) is a widely spread phenomenon which is of geochemical, environmental and biotechnological importance. While selenite bioreduction is known for a wide variety of microorganisms, selenate bioreduction is not so common and has mostly been documented for anaerobes, with merely a few reported cases related to aerobic or microaerobic conditions. In some biogenic Se NPs of microbial origin, the presence of sulfur was detected together with selenium in Se NPs, particularly when increased concentrations of sulfate were present in the medium. In this work, the bacterial strain Azospirillum thiophilum BV-S, isolated earlier from a sulfur-containing aqueous environment (Lavrinenko et al. (2010), https://doi.org/10.1099/ijs.0.018853-0), has been shown to reduce selenite to Se NPs also in the presence of 7 mM sulfate in aerobic conditions. Raman spectroscopy was used to monitor the crystallinity and composition of Se NPs formed within the bacterial biomass in the presence of selenite and in the resulting isolated Se NPs, and their spherical morphology was visualised using transmission electron microscopy (TEM). While Se NPs both within the biomass and after isolation gave a typical strong broadened band at 248 cm -1 related to the stretching Se-Se vibrations in amorphous Se 0 , Raman spectrum of the biomass grown with 1 mM selenite + 7 mM sulfate showed also a weaker band at 348 cm -1 typical of the stretching Se-S mode. The absence of the latter band in Raman spectra of the isolated Se NPs indicates that the Raman-detected Se-S bonds most probably occur in intermediate substances such as selenodiglutathione (GS-Se-SG), an intermediary product in the Painter-type reaction of selenite reduction, which is known to undergo further enzymatic transformations in bacteria resulting in the formation of Se 0 . Strain A. thiophilum BV-S has also been found, for the first time for bacteria of the genus Azospirillum, to be capable of reducing selenate (Se VI O 4 ) under static conditions (similar to microaerobic conditions common to habitats of many Azospirillum species in different environments), but not in aerobic conditions, with the formation of Se NPs. The latter, giving a reddish coloration to the bacterial biomass, were characterised by TEM as round-shaped electron-dense structures over bacterial cell images. Raman spectra of the bacterial biomass after cultivation with 5 mM selenate (with or without added sulfate) showed a similar single band at ca. 248 cm 2- in amorphous Se NPs, although 5 mM sulfate slowed down their formation. However, no signs of sulfur covalently bound to Se were observed in Raman spectra in this case. These results indicate a possible negligible role of the selenodisulfide-involving pathway in selenate reduction by A. thiophilum with a noticeable possible interference of sulfate in the process of selenate uptake (i.e., a common transport route) by A. thiophilum cells.-1 in amorphous Se NPs, although 5 mM sulfate slowed down their formation. However, no signs of sulfur covalently bound to Se were observed in Raman spectra in this case. These results indicate a possible negligible role of the selenodisulfide-involving pathway in selenate reduction by A. thiophilum with a noticeable possible interference of sulfate in the process of selenate uptake (i.e., a common transport route) by A. thiophilum cells., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Anna V. Tugarova reports financial support was provided by the Russian Science Foundation. Co-author (A.A. Kamnev) is Guest Editor of the VSI: CSI XLIII 2023 to which we submit our manuscript. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, we analyze a series of molecules belonging to the C 2V (M) molecular symmetry group which are characterized by several conformers. The use of molecular symmetry at each stage of calculating the energy of stationary torsional states is demonstrated. In particular, the importance is shown of preliminary symmetrization of physical characteristics of the molecules obtained by quantum chemical calculations. For the first time, symmetry-adapted basis functions for the diagonal kinetic coefficients are presented, which for the analyzed molecules do not satisfy all symmetry operations of the C 2V (M) group. Using the HSSSH molecule as an example, it is shown how the full or partial accounting for molecular symmetry influences the calculated values of ultra-small tunneling splittings of the ground torsional states of the trans- and cis-conformers. It has also been established that the Hamiltonian matrix is characterized by symmetry which, when taken into account, makes it possible to halve the time of calculation of its elements., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Diazotrophic bacteria of the genus Azospirillum are known widely, because they are ubiquitous in the rhizosphere and can promote the growth and performance of nonlegume plants. Recently, more Azospirillum species have been isolated from sources other than plants or soil. We report the structures of the O polysaccharides (OPSs) from the lipopolysaccharides of the type strains A. thiophilum BV-S T (1) and A. griseum L-25-5w-1 T (2), isolated from aquatic environments. Both structures have a common tetrarhamnan in the repeating-unit, which is decorated with a side xylose in the OPS of A. thiophilum BV-S T ., Competing Interests: Declaration of competing interest All authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The lipopolysaccharides of Herbaspirillum lusitanum P6-12 T (HlP6-12 T ) and H. frisingense GSF30 T (HfGSF30 T ) was isolated by phenol-water extraction from bacterial cells and was characterized using chemical analysis and SDS-PAGE. It was shown that these bacteria produce LPSs that differ in their physicochemical properties and macromolecular organization. In this paper, the lipid A structure of the HlP6-12 T LPS, was characterized through chemical analyses and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. To prove the effect of the size of micelles on their bioavailability, we examined the activity of both LPSs toward the morphology of wheat seedlings. Analysis of the HlP6-12 T and HfGSF30 T genomes showed no significant differences between the operons that encode proteins involved in the biosynthesis of the lipids A and core oligosaccharides. The difference may be due to the composition of the O-antigen operon. HfGSF30 T has two copies of the rfb operon, with the main one divided into two fragments. In contrast, the HlP6-12 T genome contains only a single rfb-containing operon, and the other O-antigen operons are not comparable at all. The integrity of O-antigen-related genes may also affect LPS variability of. Specifically, we have observed a hairpin structure in the middle of the O-antigen glycosyltransferase gene, which led to the division of the gene into two fragments, resulting in incorrect protein synthesis and potential abnormalities in O-antigen production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Lipopolysaccharide was obtained from the aerobic moderately halophilic bacterium Halomonas fontilapidosi KR26. The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide and was examined by chemical methods and by 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, and 1 H, 13 C HSQC, and HMBC experiments. The following structure of the linear tetrasaccharide repeating unit was deduced. →2)-α-l-Rhap-(1→2)-α-l-Rhap-(1→3)-α-l-Rhap-(1→3)-β-d-Galp-(1→., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The possibility of the reaction of ethylene at cryogenic temperatures with dinitrogen tetroxide (N 2 O 4 ), at least at -40 °C, has been demonstrated. An infrared (IR) spectroscopic analysis of the condensed reaction products was carried out, which showed the presence of substances containing organic nitro compounds and organic nitrates. The latter particularly means the possibility of the formation of explosive substances, as in the known explosive cryogenic reaction of N 2 O 4 with butadiene. The fundamental possibility of such a reaction is of importance for the organization of cryogenic production of gases from raw materials containing ethylene and nitrogen oxide impurities. The sensitivity of the experimental setup was demonstrated by using the example of the known reaction of N 2 O 4 with butadiene. The temperature and time characteristics of the latter reaction have been found. To determine the temperature range of possible reactions of ethylene with N 2 O 4 , thermograms of the process of heating the reactive mixture at a constant rate were analyzed. To ensure the sensitivity of the qualitative analysis of thermograms of the reaction of ethylene with N 2 O 4 in the linear heating mode, a quasi-differential method was proposed that uses the temperature of the cryo-thermostat coolant, which varies linearly with time, as the reference temperature. Some recently published theoretical results concerning the mechanisms of N 2 O 4 isomerization are discussed which may be useful for further studies in establishing the mechanisms and predicting the ratios of the products and their yields for the reaction of N 2 O 4 with olefins under particular experimental conditions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Bacterial biofilms colonize chronic wounds and surfaces of medical devices, thus making the development of reliable methods for imaging and detection of biofilms crucial. Although fluorescent identification of bacteria is sensitive and non-destructive, the lack of biofilm-specific fluorescent dyes limits the application of this technique to biofilm detection. Here, we demonstrate, for the first time, that fluorescent glutathione-stabilized gold nanoclusters (GSH-AuNCs) without targeting ligands can specifically interact with extracellular matrix components of Gram-negative and Gram-positive bacterial biofilms resulting in fluorescent staining of bacterial biofilms. By contrast, fluorescent bovine serum albumin-stabilized gold nanoclusters and 11-mercaptoundecanoic acid - stabilized gold nanoclusters do not stain the extracellular matrix of biofilms. According to molecular docking studies, GSH-AuNCs show affinity to several targets in extracellular matrix, including amyloid-anchoring proteins, matrix proteins and polysaccharides. Some experimental evidence was obtained for the interaction of GSH-AuNCs with the lipopolysaccharide (LPS) that was isolated from the matrix of Azospirillum baldaniorum biofilms. Based on GSH-AuNCs properties, we propose a new fluorescent method for the measurement of biofilm biomass with a limit of detection 1.7 × 10 5  CFU/mL. The sensitivity of the method is 10-fold higher than the standard biofilm quantification with the crystal violet assay. There is a good linear relationship between the fluorescence intensity from the biofilms and the number of CFU from the biofilms in the range from 2.6 × 10 5 to 6.7 × 10 7  CFU/mL. The developed nanocluster-mediated method of biofilm staining was successfully applied for quantitative detection of biofilm formation on urinary catheter surface. The presented data suggest that fluorescent GSH-AuNCs can be used to diagnose medical device-associated infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Splitting of the ground state and some excited symmetric bending vibrational states due to inversion tunneling of the oxygen atom in the H 3 O + , H 3 O - ions and in the H 3 O radical are analyzed by numerically solving the vibrational Schrödinger equation of restricted (2D) dimensionality. As two vibrational coordinates, we used 1) the distance of the oxygen atom from the plane of a regular triangle formed by three hydrogen atoms and 2) a symmetry coordinate composed of three distances between chemically non-bonded hydrogen atoms. The kinetic energy operator in this case takes the simplest form. The 2D potential energy surface (PES) in the given coordinates was calculated for H 3 O + at the CCSD(T)/aug-cc-pVTZ and CCSD(T)-F12/cc-pVTZ-F12 levels of theory. The same 2D PES for the H 3 O - anion and H 3 O radical were calculated at the CCSD(T)/aug-cc-pVQZ, CCSD(T)/d-aug-cc-pVQZ and UCCSD(T)/aug-cc-pVQZ, UCCSD(T)/d-aug-cc-pVQZ levels of theory, respectively. The tunneling splittings were calculated for the cations H 3 16 O + , D 3 16 O + , T 3 16 O + , H 3 18 O + , D 3 18 O + , T 3 18 O + anions and H 3 O - , D 3 O radicals were calculated for the first time. The results of calculations demonstrate good agreement with experimental values of the tunneling splittings in the ground state and in some excited vibrational states of the H - , T 3 and D - anions and H 3 O, D 3 O, T 3 O radicals were calculated for the first time. The results of calculations demonstrate good agreement with experimental values of the tunneling splittings in the ground state and in some excited vibrational states of the H 3 16 O + and D 3 16 O + cations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

An antibody-detecting sensor is described that is based on a microwave electrodynamic resonator. A polystyrene film with immobilized bacteria deposited on a lithium niobate plate was placed at one end of the resonator and was used as the sensing element. The second end was electrically shorted. The frequency and depth of the reflection coefficient S 11 for three resonances in the range 6.5-8.5 GHz were used as an analytical signal to examine antibody interactions with bacteria and determine the time required for cell immobilization. The sensor distinguished between situations in which bacteria interacted with specific antibodies and those in which no such interaction occurred (control). Although the cell-antibody interaction changed the frequency and depth of the second and third resonance peaks, the parameters of the first resonance peak did not change. The interaction of cells with nonspecific antibodies did not change the parameters of any of the peaks. These results are promising for use in the design of methods to detect specific antibodies, which can supplement the existing methods of antibody analysis., Competing Interests: Declaration of competing interest There is no conflict of interest about this article. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Ochrobactrum endophyticum (syn. Brucella endophytica) is an aerobic species of Alphaproteobacteria isolated from healthy roots of Glycyrrhiza uralensis. Here we report the structure of the O-specific polysaccharide obtained by mild acid hydrolysis of the lipopolysaccharide of the type strain KCTC 42485:→3)-α-l-FucpNAc-(1→3)-β-d-QuipNAc-(1→2)-β-d-Fucp3NAcyl-(1→ where Acyl is 3-hydroxy-2,3-dimethyl-5-oxoprolyl. The structure was elucidated using chemical analyses along with 1 H and 13 C NMR spectroscopy (including 1 H, 1 H COSY, TOCSY, ROESY and 1 H, 13 C HSQC, HMBC, HSQC-TOCSY and HSQC-NOESY experiments). To our knowledge the OPS structure is novel and has not been previously published., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Recently, there has been increased interest in the synthesis of nanoparticles by using natural polysaccharides. These polysaccharides are eco-friendly, nontoxic, and cheap to prepare. On the other hand, the attention in hydrocolloids and films has significantly enhanced, and their application is very promising in the food, pharmaceutical, perfumery and cosmetics, oil, paper, and textile industries. In this context, the present study is aimed to prepare silver nanoparticles by using viscous and superviscous exopolysaccharides of the rhizobacterium Paenibacillus polymyxa strains, CCM 1465 and 88A, and examined the properties of the resultant nanoparticles. We examined the synthesis and properties of silver nanoparticles under variable synthetic conditions by using exopolysaccharides of the rhizobacteria Paenibacillus polymyxa CCM 1465 and 88A. To prepare nanoparticles, we used different combinations of exopolysaccharide and silver nitrate concentrations: 1-10 mg/mL and 1-40 mM, respectively. The resulting solutions were alkalinized from pH 7.5-12 and heated for 15, 30, and 60 min to determine the optimal synthetic conditions. We found that the exopolysaccharides of strains CCM 1465 and 88A reduced silver ions and acted as nanoparticle stabilizers. The prepared spherical, oval, and triangular particles were stable and ranged in size from 2 to 40 nm, depending on the strain and on the experimental conditions. The nanoparticles showed antibacterial and antifungal activity against Escherichia coli K-12, Pseudomonas aeruginosa 50.3, Bacillus subtilis 26-D, and Fusarium oxysporum. In addition, the nanoparticles were active against SK-MEL-2 human melanoma cells. This finding shows the promise of further research on the exopolysaccharides of P. polymyxa 1465 and 88А in different fields of science, including medicine., Competing Interests: Declarations of interest No conflict of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The main (Mpro) and papain-like (PLpro) proteases are highly conserved viral proteins essential for replication of the COVID-19 virus, SARS-COV-2. Therefore, a logical plan for producing new drugs against this pathogen is to discover inhibitors of these enzymes. Accordingly, the goal of the present work was to devise a computational approach to design, characterize, and select compounds predicted to be potent dual inhibitors - effective against both Mpro and PLpro. The first step employed LigDream, an artificial neural network, to create a virtual ligand library. Ligands with computed ADMET profiles indicating drug-like properties and low mammalian toxicity were selected for further study. Initial docking of these ligands into the active sites of Mpro and PLpro was done with GOLD, and the highest-scoring ligands were redocked with AutoDock Vina to determine binding free energies (ΔG). Compounds 89-00, 89-07, 89-32, and 89-38 exhibited favorable ΔG values for Mpro (-7.6 to -8.7 kcal/mol) and PLpro (-9.1 to -9.7 kcal/mol). Global docking of selected compounds with the Mpro dimer identified prospective allosteric inhibitors 89-00, 89-27, and 89-40 (ΔG -8.2 to -8.9 kcal/mol). Molecular dynamics simulations performed on Mpro and PLpro active site complexes with the four top-scoring ligands from Vina demonstrated that the most stable complexes were formed with compounds 89-32 and 89-38. Overall, the present computational strategy generated new compounds with predicted drug-like characteristics, low mammalian toxicity, and high inhibitory potencies against both target proteases to form stable complexes. Further preclinical studies will be required to validate the in silico findings before the lead compounds could be considered for clinical trials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced, or appear to have influenced, the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The formation of biofilms is a key factor that researchers must consider when they work with bacterial cultures. We describe a new microfluidic bioanalytical sensory system for indicating biofilm formation. The method is demonstrated with Pseudomonas bacteria as an example and is based on the real-time recording of cell-polarizability changes caused by an alternating electric field. Control experiments using phase-contrast microscopy and traditional microbiological plating were done that proved biofilms had formed. The physical picture was described of the sensor-signal changes during cell transition from planktonic to biofilm growth. This transition was indicated by the appearance of a peak-shaped signal at 500 kHz and by an increase in the recorded relaxation time. Phenomena of increase in the signal relaxation time from 2.4 s for planktonic to 25.4 s for biofilm cells. The proposed microfluidic sensor system for indicating biofilm formation holds much promise, because it ensures an analysis time of about 20-30 min. An added bonus is that for this system there is no need to grow bacterial biofilms in a sensor and the flow cell is reusable., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Detection and study of biologically active compounds seems a promising area of research in cancer diagnostics and therapies. The glycoprotein and polysaccharide fractions showing high cytotoxicity towards several human and animal cancer cell lines: A549, Hep-2, HeLa, С6 and SPEV-2 were isolated from basidiomycete Lentinus edodes vegetative mycelium and fruiting body and further characterized. It was found that water-soluble glycoprotein fractions caused the most significant, 70-100% inhibition of metabolic activity of SPЕV-2, А549 and С6 cell lines. The effective concentrations of glycoprotein fractions reducing the viability of cancer cell lines were determined. The protein and subunit composition of fractions was studied; the highly active galactose-specific lectins were found to be present in these fractions. Comparative analysis of transcriptomes of L. edodes vegetative mycelium, fruiting body and primordium revealed the presence of carbohydrate-binding glycoproteins (lectins) specific for each stage of basidiomycete morphogenesis. Histological examination revealed some morphological indicators of immune system activation and the absence of toxic effect on gastro-intestinal mucosa of animals at peroral administration of fungal glycoprotein fractions. Fungal protein and, in particular, lectin preparations derived from L. еdodes vegetative mycelium might be considered as novel prospective tools in cancer diagnostics and therapies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The metabolic activity of growing bacteria was directly monitored by using an electro-optical (EO) sensor. The sensor enables examination of bacteria in batch and continuous cultures. As examples, we report studies with Еscherichia coli, a bacterium with an aerobic type of metabolism, and Lactobacillus plantarum, a bacterium with an anaerobic type of metabolism. Bacterial growth was accompanied by a simultaneous change in both the hydrodynamic mean size (HMS) of the bacteria and the concentration of ions in the cytoplasm (CIC). Both variables were associated with the regulation of cellular metabolic activity, which can be cyclic during intense bacterial growth. A simultaneous change in metabolic activity and osmotic regulation was also found. For СIC and HMS measurements, we used online results of the EO analysis of cells suspended in water. The measured results for the CIC and HMS can be used to directly monitor bacterial metabolism. The results of this study are of practical importance for the real-time EO monitoring of the metabolic activity of growing bacteria without preliminary sample preparation., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The O-antigen (O-polysaccharide) is an essential component of lipopolysaccharide on the surface of Gram-negative bacteria and plays an important role in interaction with host organisms. In this study, we investigated the chemical structure and characterized the gene cluster of Enterobacter cloacae K7 O-antigen. As judged by sugar analyses along with NMR spectroscopy data, E. cloacae K7 antigen has a tetrasaccharide O-unit with the following structure: →8)-β-Psep5Ac7Ac-(2 → 2)-β-l-Rhap-(1 → 4)-α-l-Rhap-(1 → 3)-α-d-Galp-(1→ The O-antigen gene cluster of E. cloacae K7 between conserved genes galF and gnd was sequenced. Most genes necessary for the O-antigen synthesis were found in the cluster and their functions were tentatively assigned by comparison with sequences in the available databases., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Monitoring of poly-3-hydroxybutyrate accumulation and changes in its relative contents in biomass of the plant-growth-promoting bacteria Azospirillum brasilense (strains Sp7, Cd and Sp245) was performed during aerobic cultivation for 1 to 8 days at various initial concentrations of bound nitrogen (0.1 to 0.5 g∙L -1 NH 4 Cl) in the culture medium using in-situ transmission FTIR spectroscopy. A methodology has been proposed based on calculating band areas in FTIR spectra (instead of band intensities commonly used earlier) for determining relative contents of PHB in dry bacterial biomass, using the ester ν(C=O) band as a PHB marker (in the region 1750-1720 cm -1 ) and amide II band of cellular proteins (at ca. 1540 cm -1 ). Differences in PHB accumulation levels and their changes in the course of cultivation under various trophic stress for the three strains are discussed in relation to their different ecological niches which they occupy in the rhizosphere., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

We have shown for the first time that it is possible to use a bacteria-based sensory system consisting of the bacterium Pseudomonas putida TSh-18 and an electro-optical sensor to detect ampicillin in the concentration range 0.5-600 μg/mL. Changes in the anisotropy of cell polarizability were detected at 900 and 2100 kHz; these represented the state of the cytoplasm and of the cell membrane, respectively. The changes indicate the quickest cell response to changes in the characteristics of the bacterial culture exposed to ampicillin. We have also shown that it is possible to monitor the ampicillin in the presence of kanamycin. In control experiments, we examined the effects of ampicillin and kanamycin on bacterial cells by phase-contrast microscopy and by standard microbiological tests on solid media. P. putida TSh-18 is recommended as a sensor system for ampicillin detection. Electro-optical analysis ensures detection of ampicillin in aquatic solutions in real-time, takes 10 min, and offers a lower limit of ampicillin detection of 0.5 μg/mL, which is lower than the European Community's maximum residue limit standards for penicillin antibiotics., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The lipopolysaccharide (LPS) of Herbaspirillum frisingense GSF30 T (HfGSF30), a non-pathogenic diazotrophic endobiont, was isolated by phenol-water extraction from bacterial cells and was characterized by chemical analyses and SDS PAGE. The O-specific polysaccharide (OPS, O-antigen), obtained by mild acid hydrolysis of the LPS, was examined by sugar and methylation analysis, along with 1 H and 13 C NMR spectroscopy, including 2D 1 H, 1 H COSY, 1 H, 1 H TOCSY, 1 H, 1 H ROESY, 1 H, 13 C HSQC, and 1 H, 13 C HMBC experiments. The OPS was found to consist of branched tetrasaccharide repeating units of the following structure: [Formula: see text] This structure is unique among the known bacterial polysaccharide structures. Analysis of the HfGSF30 genome showed that it contained a set of sequentially arranged operons (presumably a cluster of genes) associated with the O-antigen. Amino acid sequence analysis using the BLAST program demonstrated the specificity of this putative cluster for Herbaspirillum spp. The genes responsible for the biosynthesis of the OPS of HfGSF30 were dispersed in the genome, constituting small operons. A putative O-antigen gene cluster of HfGSF30 was identified and found to be consistent with the OPS structure., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The hydrogen trioxide (HT) molecule HOOOH is 1) a prototype for a class of molecules of the form X(ZY) 2 with two equivalent internal tops (ZY) and 2) the second representative of the polyoxides series of the form HO n H (n ≥ 2). Due to this, it is the subject of close attention of researchers. In this paper, we performed a group theory analysis of the torsional and spin states of the HOOOH, DOOOH, and DOOOD molecules. The relationships have been established between the symmetry species of the C 2V (M) molecular symmetry group to which the HOOOH and DOOOD molecules belong, and the symmetry species of the C 2 and C S point groups to which the equilibrium configurations of trans- and cis-conformers of the above molecules belong, respectively. 2D PES and 2D surfaces of kinematic coefficients related to torsional vibrations of hydroxyl groups were calculated at the complete basis set (CBS) limit by extrapolating the results of calculations at the MP2/cc-pVTZ and MP2/cc-pVQZ levels of theory. For all the three molecules, the energies of the stationary torsional states were computed using the Fourier method for a numerical solution of the 2D vibrational Schrödinger equation. Symmetry species of torsional states and the values of quantum numbers defining the types of torsional vibrations were found by analyzing the torsional wave functions. The selection rules for transitions between torsional states in the dipole approximation were also formulated., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Microbial reduction of selenium oxyanions has attracted attention in recent years. In this study, an original and simple method for the synthesis of extracellular selenium nanoparticles (Se NPs) of relatively uniform size has been developed using strains Sp7 and Sp245 of the ubiquitous plant-growth promoting rhizobacterium Azospirillum brasilense, both capable of selenite (SeO 3 ) reduction. In addition, a reliable purification protocol for the recovery of the Se NPs has been perfected, which could be applied with minor modifications to cultures of other microbial species. Importantly, it was found that, by changing the conditions of bacterial reduction of selenite, extracellularly localised Se NPs can be obtained using bacteria which would otherwise produce intracellular Se NPs. In particular, bacterial cultures grown up to the end of the logarithmic growth phase, washed free of culture medium and then incubated with selenite, were used to obtain extracellular Se NPs. Their sizes depended on the initial selenite concentration (∼25-80 nm in diameter at 50-10 mM selenite, respectively). The Se NPs obtained were characterised by transmission electron microscopy (TEM), dynamic light scattering, as well as Raman and UV-vis spectroscopies. Their zeta potential was found to be negative (ca. minus 21-24 mV). Bacterial selenite reduction was also studied in the presence of the efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP). In this case, TEM indicated the formation only of intracellular selenium crystallites. The data show that the formation of extracellular Se NPs requires normal bacterial metabolic activity, while CCCP evidently blocks the membrane export of Se 2- ) reduction. In addition, a reliable purification protocol for the recovery of the Se NPs has been perfected, which could be applied with minor modifications to cultures of other microbial species. Importantly, it was found that, by changing the conditions of bacterial reduction of selenite, extracellularly localised Se NPs can be obtained using bacteria which would otherwise produce intracellular Se NPs. In particular, bacterial cultures grown up to the end of the logarithmic growth phase, washed free of culture medium and then incubated with selenite, were used to obtain extracellular Se NPs. Their sizes depended on the initial selenite concentration (∼25-80 nm in diameter at 50-10 mM selenite, respectively). The Se NPs obtained were characterised by transmission electron microscopy (TEM), dynamic light scattering, as well as Raman and UV-vis spectroscopies. Their zeta potential was found to be negative (ca. minus 21-24 mV). Bacterial selenite reduction was also studied in the presence of the efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP). In this case, TEM indicated the formation only of intracellular selenium crystallites. The data show that the formation of extracellular Se NPs requires normal bacterial metabolic activity, while CCCP evidently blocks the membrane export of Se 0 nuclei., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The lipopolysaccharide was obtained from the cells of Azospirillum formosense CC-Nfb-7(T), a diazotrophic bacterium isolated from agricultural soil. The O-specific polysaccharide (OPS) was released by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, 1 H, 13 C HSQC, and HMBC experiments, and Smith degradation. The following structure of partially methylated OPS composed of trisaccharide repeating units was established., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Lipopolysaccharide (LPS) of Ochrobactrum cytisi IPA7.2, a bacterium isolated from the roots of Solanum tuberosum L., was extracted from dry bacterial cells and chemically characterized. The O-specific polysaccharide was obtained by mild acid hydrolysis of the LPS and studied by sugar analysis and 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, 1 H, 1 H TOCSY, 1 H, 1 H ROESY, 1 H, 13 C HSQC, and 1 H, 13 C HMBC experiments. The polysaccharide was linear and consisted of trisaccharide repeating units of the following structure: A putative O-antigen gene cluster of O. cytisi IPA7.2 was identified and found to be consistent with the O-specific polysaccharide structure. The LPS of Ochrobactrum cytisi IPA7.2 promoted the growth of potato microplants in vitro., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The structures and cytotoxic activities of water-soluble polysaccharides were investigated to search for biologically active polysaccharides from the fruit bodies of quinine conks (Fomitopsis officinalis). The decoctions of this medical fungus are actively used in folk medicine in many countries and traditional Chinese medicine. From the fungal extract we prepared, only branched β-glucan had cytotoxic activity among all the water-soluble polysaccharides. This glucan is characterized by a regular structure. Its backbone is formed by 1,3-linked β-D-Glcp residues, of which every third residue is substituted at O-6 by a single β-D-Glcp residue. It has a triple helix conformation according to the data obtained from a colorimetric assay with Congo red dye and is characterized by a high-weight average molar mass (Mw > 800 kDa). β-Glucan possessed cytotoxic activity against HeLa cells (IC 50  = 318 ± 47 μg/mL) and induced the formation of apoptotic bodies around most cancer cells at a concentration of 200 μg/mL. It should be noted that extraction with boiling water, which is usually used to obtain extracts and decoctions, is unable to isolate active β-glucan. Active β-glucan can be obtained in an individual state by cold alkali extraction after dehydration of the fruit bodies and removal of the components extractable by boiling water., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Glycosylated flagellin of the polar flagellum of the plant growth-promoting rhizobacteria Azospirillum brasilense Sp245 was for the first time isolated and characterized by biochemical and bioinformatics methods. Using the amino acid sequence taken from the NCBI database of bacterial whole-genome DNA sequencing, the secondary and tertiary structures of the protein part of this glycoprotein were determined by template-based molecular modeling. With the use of a set of predictors, regions of its intrinsic structural disorder were identified, and binding sites of carbohydrate fragments to the surface of the molecule were determined. A positive effect of the polar flagellum flagellin on the root meristem of wheat seedlings was for the first time revealed for associative bacteria. The effect was manifested in an increase in the division rate of plant cells - a significant increase in the mitotic index. Thus, the induction of specific responses of plants to their interactions with flagellin of the associative bacteria may probably be considered as a demonstration of its elicitor properties., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Microbial cells are well known to be capable of remaining viable when desiccated, and a variety of beneficial microorganisms can thus be preserved for storage. For the ubiquitous widely studied soil bacterium Azospirillum brasilense (wild-type strain Sp7), which has a significant agrobiotechnological potential owing to its plant-growth-promoting capabilities perspective for its use in biofertilisers, Fourier transform infrared (FTIR) spectroscopy (in the diffuse reflectance mode, DRIFT) was used to control the state of biomass, together with 57 Fe transmission Mössbauer spectroscopy to monitor intracellular iron speciation in live rapidly frozen cell suspension and in the lyophilised biomass (both measured at T = 80 K). It has been shown for the first time that a relatively large part of ferrous iron in live cells (22% of the whole cellular iron pool, represented by two high-spin Fe(II) forms, in the 18-h culture grown on 57 Fe(III) complex with nitrilotriacetic acid as the sole source of iron) gets largely oxidised upon lyophilisation. The remaining part of iron(II) in the resulting dry biomass was found to be ca. 3% only. The major part of ferric iron in the dry biomass was shown to be comprised of ferritin-like ferric species (giving a typical magnetically split sextet at T = 5 K), while the iron(III) formed from cellular iron(II) by oxidation in air in the course of drying remained in a paramagnetic state even at T = 5 K. The possibility of intracellular iron(II) oxidation to iron(III) upon desiccation may be a specific natural strategy to avoid cell damage caused by Fenton-type reactions in dormant (frozen, dried) cells. The results obtained may have important implications related to iron speciation and redox transformations in dried bacterial preparations intended for long-term storage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A sheep single-chain antibody-fragment library (Griffin.1, UK) was used to obtain miniantibodies to the lipopolysaccharide of Herbaspirillum seropedicae Z78. Using electro-optical analysis and electron microscopy, we recorded a biospecific interaction of antigenic determinants on the cell surface with phage antibodies against the LPS of H. seropedicae Z78 (mini-Abs LPS ). Control experiments were run to rule out nonspecific binding of the mini-Abs LPS to cells of Azospirillum brasilense Sp245. Use of the highly specific mini-Abs LPS enabled the lipopolysaccharide of H. seropedicae Z78 to be detected in a mixture of bacterial cells by electro-optical means (analysis time, ∼5 min). This report is the first to show the possibility of rapid detection of Herbaspirillum on the basis of electro-optical analysis coupled with the use of mini-Abs LPS . The results are promising for the development of biosensor-based methods to detect potentially human-harmful prokaryotes whose structures either have not been studied or are absent from commercial databases., (Copyright © 2019 Elsevier B.V. All rights reserved.)

O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of plant-growth-promoting rhizobacteria Azospirillum doebereinerae GSF71 T and studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 2D 1 H, 1 H COSY, TOCSY, ROESY, 1 H, 13 C HSQC, and HMBC experiments. It was established that the polysaccharide is linear and consists of tetrasaccharide repeating units with the following structure., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Lipopolysaccharide (LPS) was extracted from dry bacterial cells of plant-growth-promoting bacterium Azospirillum brasilense SR8 (IBPPM 5). The O-specific polysaccharide (OPS) was obtained by mild acid hydrolysis of the lipopolysaccharide and studied by sugar analysis, 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, and 1 H, 13 C HSQC and HMBC experiments, computational NMR-based structure analysis, and Smith degradation. The OPS was shown to contain two types of repeating units of the following structure: Both OPS structures are present in A. brasilense 54, from which structure 1 has been reported earlier (Fedonenko et al., 2011), whereas to our knowledge structure 2 has not been hitherto found in bacterial saccharides. Treatment of wheat seedling roots with LPS of A. brasilense SR8 increased the number of root hair deformations as compared to seedlings grown without LPS, but had no effect on adsorption of the bacteria to the root surface. A. brasilense SR8 was able to utilize LPS of several structurally related Azospirillum strains., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Halomonas ventosae RU5S2EL, a halophilic Gram-negative bacterium isolated from salt sediments of lake Elton (Russia), was cultivated and the lipopolysaccharide was extracted by the Westphal procedure. The O-specific polysaccharide (OPS) was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, 1 H, 13 C HSQC, and HMBC experiments as well as Smith degradation. The OPS was found to consist of branched pentasaccharide repeating units of the following structure., (Copyright © 2018. Published by Elsevier Ltd.)

The structure of potential bacteriophage receptors located on cell walls of Gram-negative bacteria deposited at Belarusian collection of microorganisms was investigated. Studies by 1D and 2D 1 H and 13 C NMR spectroscopy enabled to elucidate the structure of the O-specific polysaccharides (OPS) constituting lipopolysaccharide (LPS) of some Pseudomonas species. The capacity of bacteriophage to adsorb to LPS molecules was tested., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The possibility of the registration of the interaction of the cells Azospirillum lipoferum Sp59b with the specific antibodies directly in the conducting suspensions by using an acoustic sensor was shown. The main element of the sensor is a piezoelectric resonator with a lateral electric field. The analysis is based on a comparison of the resonator's electrical impedance before and after the specific biological interaction between the cells and antibodies. By using this sensor one can detect and identify the bacterial cells directly in the buffer solution with the conductivity between 2.4 and 20 μS/cm. The minimum detectable concentration of the bacterial cells turned out to be ∼10 3  cells/ml and for a short time (less than 10 min). Also the possibility of the detection of the cells in the presence of the extraneous microflora was shown. The results provide the opportunities for the development of a new class of the methods for the analysis of the microbial cells in real-time directly in the buffer solution., (Copyright © 2018 Elsevier Inc. All rights reserved.)

O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of nitrogen-fixing bacterium Azospirillum fermentarium CC-LY743 T (IBPPM 578) and was studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, and 1 H, 13 C HSQC and HMBC experiments. The polysaccharide was found to be linear and to consist of alterating α-l-fucose and α-d-mannose residues in tetrasaccharide repeating units of the following structure: →2)-α-D-Manp-(1 → 3)-α-L-Fucp-(1 → 3)-α-D-Manp-(1 → 3)-α-L-Fucp-(1→., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Raman spectra of liquid water and ice were measured at different temperatures. The intensity of the band assigned to bending vibrations of water molecules was observed to decrease at the liquid-to-solid transition, while the Raman line near 2200cm -1 showed an anomalously high intensity in the solid phase. A tetrahedral model was used for computer analysis of the observed spectral changes. Quantum-chemical calculations of the structure, normal vibrations and Raman spectra in the harmonic approximation, as well as frequencies and intensities of some vibrations using 1D and 2D potential energy surfaces, were carried out using B3LYP with the cc-pVTZ basis set. The influence of the number of hydrogen bonds on the frequency and Raman activity of the bending vibrations was analyzed. The possibility of hydrogen bond weakening upon excitation of the combined bending-rocking vibration due to the large amplitude of this vibration is considered., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO 3 ) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250nm; their zeta potential was measured to be minus 18.5mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500cm 2- ) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250nm; their zeta potential was measured to be minus 18.5mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500cm -1 down to 150cm -1 ) showed a single very strong band with a maximum at 250cm -1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The electro-acoustical sensor for the real-time identification of the bacteriophage FAl-SR65 is described. The polyclonal antibodies specific to the bacteriophage FAl-SR65 were for the first time obtained, and the possibility of their application to the bacteriophage detection by using the electro-acoustical method of analysis was also studied for the first time. The electro-acoustical sensor was based on the lateral electric field excited piezoelectric resonator. The frequency dependences of the real and imaginary parts of the electrical impedance of such a resonator, loaded with the virus-antibody suspension, significantly differed from those measured for the same resonator with the same virus suspension but without antibodies (control). The limit for the reliable bacteriophage detection during their interaction with the antibodies (sensitivity level) was determined to be 10 6 phages ml -1 . The obtained results demonstrate the possibility to record the bacteriophage-antibody interactions and can be used as the basis for the development of the biological sensor for the quantitative virus detection., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this review, the unique possibilities are considered of the 57 Fe transmission (TMS) and 57 Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues. Recent representative examples of analyses of Fe-containing proteins by 57 Fe TMS are briefly discussed, along with the newly emerging data on using 57 Co EMS for probing the structural organisation of 57 Co-doped cation-binding sites in sophisticated biocomplexes including metalloenzymes. Finally, some rare or exotic applications of Mössbauer spectroscopy (including the synchrotron-based methodology) in protein-related studies are outlined., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Biogenic formation of nano-sized particles composed of various materials (in particular, selenium) by live microorganisms is widespread in nature. This phenomenon has been increasingly attracting the attention of researchers over the last decade not only owing to a range of diverse applications of such nanoparticles (NPs) in nanobiotechnology, but also because of the specificity of methodologies and mechanisms of NPs formation related to "green synthesis". In this mini-review, recent data are discussed on the multifaceted role of proteins in the processes of microbial reduction of selenium oxyanions and the formation of Se NPs. Besides the involvement of proteins in reducing selenites and selenates, their participation in the microbially driven growth and stabilisation of Se NPs is analysed, which results in the formation of unique nanostructured materials differing from those obtained chemically. This mini-review is thus focussed on proteins involved in microbial synthesis of Se NPs and on instrumental analysis of these processes and their products (biogenic nanostructured selenium particles functionalised by a surface-capping layer of various biomacromolecules)., (Copyright © 2017 Elsevier B.V. All rights reserved.)

An O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of bacteria Pseudomonas putida TSh-18, capable of degrading non-ionogenic technical detergents. The polysaccharide was found to contain a rarely occurring sugar derivative 4,6-dideoxy-4-[(R)-3-hydroxybutanoylamino]-d-galactose [d-Fucp4N(RHb)]. Sugar and methylation analyses, Smith degradation, solvolysis with CF 3 CO 2 H, and 1 H and 13 C NMR spectroscopy enabled elucidation of the following structure of the branched trisaccharide repeating units of the polysaccharide., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A major challenge in the field of nanomedicine is to transform laboratory innovations into commercially successful clinical products. In this campaign, a variety of nanoenabled approaches have been designed and investigated for their role in biomedical applications. The advantages associated with the unique structure of albumin imparts it with the ability to interact with variety of molecules, while the functional groups present on their surface provide base for large number of modifications making it as an ideal nanocarrier system. So far, a variety of albumin based nanoenabled approaches have been intensively exploited for effective diagnosis and personalized medicine, among them some have successfully completed their journey from lab bench to marketed products. This review focuses on the recent most promising advancement in the field of albumin based nanoenabled approaches for various biomedical applications and their potential use in cancer diagnosis and therapy., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The single-stranded transfer DNA from the Ti plasmid of the soil bacteria Agrobacterium nonspecifically integrates into the plant chromosome and is inherited at subsequent cell divisions. How it is transferred across host membranes is unknown, but it is believed that VirE2 proteins form a membrane-spanning pore or channel in a lipid bilayer and possibly mediate the delivery of the single-stranded transfer DNA-VirD2-VirE2 complex to the plant cell chromosomes. The aim of this work was to perform a computer simulation of VirE2's pore-forming capacity and an evaluation of constructed VirE2 complexes. The oscillating motions of complexes consisting of two and four VirE2 subunits were estimated by the molecular dynamics and normal modes methods. We did not predict any large changes in domain orientation for two and four-subunit VirE2 complexes within simulation times of 1ns. A possible gating mechanism similar to that seen in the ion channels of the complex formed from two VirE2 proteins was proposed, whereas no conformational changes were predicted inside the pore in the complex formed from four VirE2 proteins., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In the emission ( 57 Co) variant of Mössbauer spectroscopy (EMS), the 57 Co radionuclide (with a half-life of 9months) is used that undergoes a nuclear decay 57 Co→ 57 Fe via electron capture followed by the emission of a γ-quantum, the energy of which is modified by the chemical state and the close coordination environment of the parent 57 Co atom. While EMS has been used largely in materials science and nuclear chemistry, its high sensitivity can also be of great advantage in revealing fine structural features and for speciation analysis of biological complexes, whenever the 57 Co 2+ cation can be used directly as the coordinating metal or as a substitute for native cobalt or other metal ions. As such EMS applications are yet rare, in order to reliably interpret emission spectra of sophisticated 57 Co 2+ -doped biosystems, model EMS studies of simple cobalt biocomplexes are necessary. In this work, EMS spectroscopic data are analysed and discussed for 57 Co 2+ complexes with a range of small biomolecules of different structures, including 4-n-hexylresorcinol, homoserine lactone and a few amino acids (spectra measured in rapidly frozen dilute aqueous solutions or in the dried state at T=80K). The EMS data obtained are discussed with regard to the available literature data related to the coordination modes of the biocomplexes under study., (Copyright © 2016. Published by Elsevier B.V.)

Novel chitosan-based nanofibrous composite materials containing different amounts of the photosensitizer Photosens were obtained by electrospinning and were characterized by scanning electron microscopy and by confocal laser scanning microscopy. The release of Photosens from the materials was investigated in water and in phosphate-buffered saline. A noncancerous (MC3T3-E1 murine osteoblasts) and a cancerous [T-47D (mammary gland)] cell line were cultivated on Photosens-containing scaffolds, and cell growth and metabolic activity were examined by confocal laser scanning microscopy and by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide assay, respectively. The viability of both cell lines on Photosens-containing fibers decreased in a spatial manner upon laser irradiation of an appropriate wavelength and power density. Interestingly, the noncancerous MC3T3-E1 cells grown on Photosens -containing scaffolds were less affected by the irradiation. We conclude that the Photosens-containing electrospun chitosan nanofibers described here are of potential interest for biomedical applications, particularly topical photodynamic therapy and tissue engineering., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Photosynthesis is a highly robust process allowing for rapid adjustment to changing environmental conditions. The efficient acclimation depends on balanced redox metabolism and control of reactive oxygen species release which triggers signaling cascades and potentially detrimental oxidation reactions. Thiol peroxidases of the peroxiredoxin and glutathione peroxidase type, and ascorbate peroxidases are the main peroxide detoxifying enzymes of the chloroplast. They use different electron donors and are linked to distinct redox networks. In addition, the peroxiredoxins serve functions in redox regulation and retrograde signaling. The complexity of plastid peroxidases is discussed in context of suborganellar localization, substrate preference, metabolic coupling, protein abundance, activity regulation, interactions, signaling functions, and the conditional requirement for high antioxidant capacity. Thus the review provides an opinion on the advantage of linking detoxification of peroxides to different enzymatic systems and implementing mechanisms for their inactivation to enforce signal propagation within and from the chloroplast.