The pathogenic microorganism Staphylococcus aureus, one of the representatives of the staphylococcus family, is capable of developing resistance to antibiotics and antiseptics. The largest ribosomal protein, S1, from S. aureus contains four structural S1 domains, and short peptides synthesized based on its sequence have amyloidogenic and antimicrobial properties (antimicrobial peptides). In this work, in silico analysis of all available ribosomal protein S1 sequences from various S. aureus strains allowed us to identify residues that are characteristic of specific strains. Based on data from the I-Mutant service, changes in the stability of ribosomal protein S1 from various S. aureus strains were predicted. The results obtained will be used in the future for targeted mutations in the design of new antimicrobial peptides based on ribosomal protein S1.

Alzheimer’s disease (AD) has been and remains the main cause of dementia in aging patients. This neurodegenerative disease belongs to the progressive and socially significant ones. There are several hypotheses for the development of AD: the tau hypothesis, the amyloid cause, the cholinergic cause, the cause of oxidative stress and inflammation. The lack of a generally accepted understanding of the etiology and pathogenesis of AD hinders the development of new effective mechanisms for its treatment and prevention. In 2021, for the first time, a drug for pathogenetic therapy of AD (aducanumab) was approved, which helps to reduce the content of amyloid-β peptide (Aβ) in the brain of patients. Another promising approach to the treatment of AD, aimed at removing Aβ from the patient’s central nervous system, is the impact on human serum albumin (HSA), which carries 90% of Aβ in the blood serum and 40–90% of Aβ in the cerebrospinal fluid. In clinical practice, plasmapheresis has already been tested and shown to be effective with the replacement of one’s own HSA with a purified therapeutic albumin preparation. Another variant of this approach is to enhance the interaction of HSA with Aβ through the action of exogenous and endogenous HSA ligands, such as serotonin, ibuprofen and some unsaturated fatty acids. In vivo studies confirm the association of this group of ligands with the pathogenesis of AD. These substances are well-studied natural metabolites or drugs, which greatly simplifies the development of new methods of therapy and prevention of AD with their use. In general, a new direction of scientific research devoted to the study of HSA as a carrier and depot of Aβ in the blood and cerebrospinal fluid will expand our understanding of Aβ metabolism and its role in the pathogenesis of AD.

A new facultative methylotroph, strain 6x-1T, was isolated from the phyllosphere of oak (Quercus pubescens Willd.) on the medium with methanol. Cells were aerobic, gram-negative, not-spore-forming, non-motile short ovoids rods reproducing by binary fission. Growth optimum was at 25‒29°C and pH 7.0‒7.5; growth was inhibited by 1.5

The possibility of using redox-active polymers based on bovine serum albumin (BSA) and chitosan covalently linked to neutral red, thionine, and ferrocene mediators, and containing carbon nanotubes (CNTs) for glucose-oxidase immobilization is investigated. The structure of the obtained polymers is studied by infrared (IR) spectroscopy, spectrophotometry, atomic-absorption spectroscopy, and scanning electron microscopy. Using the method of cyclic voltammetry, the electrochemical characteristics of the studied conductive nanocomposite systems are found, namely, a heterogeneous rate constant of electron transfer and a rate constant of interaction with glucose oxidase. The systems containing a redox-active polymer based on BSA modified with a ferrocene mediator turn out to be the most promising. Biosensors formed using nanocomposite matrices have a high sensitivity with a lower limit of determined glucose concentrations of 0.1 mM and are characterized by a high correlation (R 2 = 0.9827) with the results of determining the glucose content in human blood by the standard method.

The consortium of symbiotic strains of lactobacilli Lactobacillus plantarum MDIIE 2165 and Lactobacillus rhamnosus MDIIE 2166, deposited in the All-Russian Collection of Microorganisms (IBFM RAS), is the most suitable starter for obtaining a fermented beet juice (FBJ). These innovative probiotic lactobacilli ensure a deep processing of raw materials and allow a specialized food product with high organoleptic characteristics, biological value and adaptogenic properties to be obtained. FBJ can be used as a specialized nutrition product to improve the performance of athletes and people working and living in extreme conditions, as well as to prolong the professional longevity of the population.

An original approach to the development of antimicrobial peptides (AMPs) with a new mechanism of action based on directed coaggregation of a peptide with a target protein is proposed. The unique multifunctional bacterial ribosomal protein S1 was chosen as the target protein. The amyloidogenic and antibacterial effects of various peptides synthesized on the basis of S1 ribosomal protein sequences were studied. The results obtained can serve as a basis for the creation of new AMPs against various strains of pathogenic organisms.

Bacterial cellulose (BC) produced by the Komagateibacter sucrofermentas VKPM B-11267 bacteria was used as a carrier for immobilization of acetic acid bacteria Gluconobacter oxydans in amperometric biosensors. The bioreceptor was formed on the surface of a screen-printed graphite electrode modified with thermally expanded graphite (TEG) or on the surface of a porous three-dimensional material, nickel foam (NF). Structural features of these materials contributed to the creation of a firm contact between the electrode material and the surface of the BC on which the bacterial cells were immobilized. Scanning electron microscopy showed that bacteria not only sorb on the surface of BC but are also able to penetrate the inner volume of the film. Conductivity of both types of biosensors was studied using impedance spectroscopy and the resistance of the graphite electrode was shown to decrease by three orders of magnitude after its surface is modified with TEG. Bioelectrodes containing BC were used in the construction of an amperometric biosensor for glucose determination. The sensitivity of the biosensor was 3 μA/mM × cm2. Thus, BC in combination with TEG and NF can be used to create three-dimensional electrodes of bioelectrocatalytical devices.

A new approach has been developed for the formation of the biosensor recognition elements via the immobilization of microorganisms in layer-by-layer films in order to determine the biochemical oxygen demand (BOD). Bioreceptor elements of BOD-biosensors have been fabricated based on the bacterial microorganisms Paracoccus yeei, Pseudomonas veronii, and Bacillus proteolyticus isolated from activated sludge. The recognition element was formed with via layer-by-layer deposition; each layer contained cells of one species. A similar multilayered recognition element based on yeast cells of Ogataea angusta , Blastobotrys adeninivorans, and Debaryomyces hansenii was created . In both cases, the cells were immobilized in a hydrogel of polyvinyl alcohol modified with N -vinylpyrrolidone. It was found that layer-by-layer immobilization increases the sensitivity of both the yeast- and bacterial cell–based biosensors. It was surmised that this is due to the lack of competition for substrate within the layer and its greater ability to each of the cell layers. The effects of the composition of the assayed samples (pH, ionic strength, heavy metal compounds) on the oxidative activity of the developed recognition elements have been studied. The analytical and metrological characteristics of the biosensors have been defined. The lower limit of the estimated BOD 5 values was 0.5 mg О 2 /dm 3 and 0.7 mg О 2 /dm 3 for bacterial- and yeast cell–based biosensors, respectively. BOD 5 was detected in water samples with the fabricated recognition elements. It was shown that the use of these two bioreceptors makes it possible to obtain data that strongly agree with those obtained with traditional method and that biosensing analyzers can act as prototype pilot model of the devices

The review summarizes and systematizes the data on the classification, taxonomic distribution, structural features, and functions of proteins with structural repeats. Modern approaches to the identification of structural repeats in proteins are considered. Features of specialized databases of protein domains are described. The review discusses the prospects of using repeat-containing proteins as scaffolds for drug design. The role of proteins with structural repeats in the pathogenesis of various diseases is considered. Various modern approaches to understanding the mechanisms of the evolutionary development of proteins with repeats are described and analyzed.

Bacteriocins are bacterial proteins or peptides exhibiting antimicrobial activity and synthesized on ribosomes. For a high molecular weight bacteriocin produced by the Limosilactobacillus fermentum IIE MD-150 strain and having the GRAS status (Generally Recognized as Safe), an amino acid sequence homology with enterolysin A produced by the Enterococus faecalis LMG 2333 strain was found. Lactobacillus fermentum IIE MD-150 can be used in the prevention and complex treatment of infectious diseases caused by antibiotic-resistant strains of Staphylococcus aureus.

The use of a biomodel of the confluent monolayer Caco-2 of enterocytes allowed us to reveal the ability of the S-protein isolated from strain LC2029 to prevent permeability disorders resulting from intestinal infections induced by pathogens (E. coli O157: H7, C. jejuni ATCC 33291, S. enteritidis ATCC 25928). This is important for maintaining the efficiency of the intestinal barrier.

In order to solve the demographic problem that has arisen in Russia, comprehensive multilateral approaches are required, aimed at increasing the birth rate and reducing child and adult mortality. One approach to solve this problem is directed regulation of the human microbiome.

The Streptomyces sp. VKM Ac-2618D strain has been identified, and its morphological and physiological features have been studied in relation to the production of the immunosuppressant tacrolimus. The phenotypic variability of the strain was analyzed, and a dissociant with a high level of tacrolimus production was selected. Based on a comprehensive study of morphological, physiological, and chemotaxonomic properties and on phylogenetic analysis, the strain was named Streptomyces tsukubensis VKM Ac-2618D. The strain genome contains the full version of the tacrolimus biosynthetic gene cluster. The advantages of fed-batch cultivation mode for tacrolimus biosynthesis are shown. The results broaden the understanding of the characteristics of polyketide biosynthesis and can be used in the development of technology for tacrolimus production.

Bacteriocins are bacterial proteins or peptides exhibiting antimicrobial activity and synthesized on ribosomes. For a high molecular weight bacteriocin produced by the Limosilactobacillus fermentum IIE MD-150 strain and having the GRAS status (Generally Recognized as Safe), an amino acid sequence homology with enterolysin A produced by the Enterococus faecalis LMG 2333 strain was found. Lactobacillus fermentum IIE MD-150 can be used in the prevention and complex treatment of infectious diseases caused by antibiotic-resistant strains of Staphylococcus aureus.