The paper represents the study of interaction between deoxyribonucleic acid (DNA) and deoxyribonucleic acid-binding protein from starved cells (DPS) cluster formation and crystal growing within a cell. This study is a part of the project that includes European Synchrotron Radiation Facility (ESRF) investigations of in vivo and in vitro nanocrystallization processes of Escherichia coli (E. coli) nucleoid under stress condition combined with theoretical molecular dynamics approaches. Nucleoid biocrystallization is an adaptive mechanism of bacterial cells under stress. It is poorly understood at the present time. Understanding crystal formation process is a very important for molecular biology, pharmacology and other areas. In the simulation part the coarse-grained modeling of various combinations of the following molecules was used: DPS proteins (from 1 to 108 DPS dodecamers in simulation box), short DNA fragments with a length of 24 base pairs (b.p., from 1 to 100 DNA fragments in simulation box) and a part of pBluescript SK(+) plasmide with a length of 161 b.p., in the presence of ions. We defined structural, energetic and dynamic properties of DPS-DPS and DPS-DNA complexes in clusters and crystals that allow us to predict crystal formation and the structure of these crystals in experimental systems. Communicated by Ramaswamy H. Sarma

Gradual dehydration is one of the frequent lethal yet poorly understood stresses that bacterial cells constantly face in the environment when their micro ecotopes dry out, as well as in industrial processes. Bacteria successfully survive extreme desiccation through complex rearrangements at the structural, physiological, and molecular levels, in which proteins are involved. The DNA-binding protein Dps has previously been shown to protect bacterial cells from many adverse effects. In our work, using engineered genetic models of E. coli to produce bacterial cells with overproduction of Dps protein, the protective function of Dps protein under multiple desiccation stresses was demonstrated for the first time. It was shown that the titer of viable cells after rehydration in the experimental variants with Dps protein overexpression was 1.5–8.5 times higher. Scanning electron microscopy was used to show a change in cell morphology upon rehydration. It was also proved that immobilization in the extracellular matrix, which is greater when the Dps protein is overexpressed, helps the cells survive. Transmission electron microscopy revealed disruption of the crystal structure of DNA–Dps crystals in E. coli cells that underwent desiccation stress and subsequent watering. Coarse-grained molecular dynamics simulations showed the protective function of Dps in DNA–Dps co-crystals during desiccation. The data obtained are important for improving biotechnological processes in which bacterial cells undergo desiccation.

Silver-based metal–organic decomposition inks composed of silver salts, complexing agents and volatile solvents are now the subject of much research due to the simplicity and variability of their preparation, their high stability and their relatively low sintering temperature. The use of this type of ink in inkjet printing allows for improved cost-effective and environmentally friendly technology for the production of electrical devices, including flexible electronics. An approach to producing a silver salt-based reactive ink for jet printing has been developed. The test images were printed with an inkjet printer onto polyimide substrates, and two-stage thermal sintering was carried out at temperatures of 60 °C and 100–180 °C. The structure and electrical properties of the obtained conductive lines were investigated. As a result, under optimal conditions an electrically conductive film with low surface resistance of approximately 3 Ω/square can be formed.

Acidisarcina polymorpha SBC82^T is a recently described representative of the phylum Acidobacteriota from lichen-covered tundra soil. Cells of this bacterium occur within unusual saccular chambers, with the chamber envelope formed by tightly packed fibrils. These extracellular structures were most pronounced in old cultures of strain SBC82^T and were organized in cluster-like aggregates. The latter were efficiently destroyed by incubating cell suspensions with cellulase, thus suggesting that they were composed of cellulose. The diffraction pattern obtained for 45-day-old cultures of strain SBC82^T by using small angle X-ray scattering was similar to those reported earlier for mature wood samples. The genome analysis revealed the presence of a cellulose biosynthesis locus bcs. Cellulose synthase key subunits A and B were encoded by the bcsAB gene whose close homologs are found in genomes of many members of the order Acidobacteriales. More distant homologs of the acidobacterial bcsAB occurred in representatives of the Proteobacteria. A unique feature of bcs locus in strain SBC82^T was the non-orthologous displacement of the bcsZ gene, which encodes the GH8 family glycosidase with a GH5 family gene. Presumably, these cellulose-made extracellular structures produced by A. polymorpha have a protective function and ensure the survival of this acidobacterium in habitats with harsh environmental conditions.