Composite Hydrogels Based on Bacterial Cellulose and Poly-1-vinyl-1,2,4-triazole/Phosphoric Acid: Supramolecular Structure as Studied by Small Angle Scattering.

New composite hydrogels (CH) based on bacterial cellulose (BC) and poly-1-vinyl-1,2,4-triazole (PVT) doped with orthophosphoric acid (oPA), presenting interpenetrating polymeric networks (IPN), have been synthesized. The mesoscopic study of the supramolecular structure (SMS) of both native cellulose, produced by the strain , and the CH based on BC and containing PVT/oPA complex were carried out in a wide range of momentum transfer using ultra- and classical small-angle neutron scattering techniques. The two SMS hierarchical levels were revealed from 1.

Matrix is everywhere: extracellular DNA is a link between biofilm and mineralization in Bacillus cereus planktonic lifestyle.

To date, the mechanisms of biomineralization induced by bacterial cells in the context of biofilm formation remain the subject of intensive studies. In this study, we analyzed the influence of the medium components on the induction of CaCO precipitation by the Bacillus cereus cells and composition of the extracellular matrix (ECM) formed in the submerged culture. While the accumulation of extracellular polysaccharides and amyloids appeared to be independent of the presence of calcium and urea during the growth, the accumulation of extracellular DNA (eDNA), as well as precipitation of calcium carbonate, required the presence of both ingredients in the medium.

New copolyhydrazides with anthrazoline fragments in the main chain: synthesis and optical properties.

Several new 2,8-diphenylpyrido[3,2-g]quinoline-4,6-dicarbohydrazides were synthesized and copolyhydrazides based on them were obtained. Molecular weight, thermal, stress-strain and optical properties were investigated. It was shown that all polymer films exhibit significant luminescence in the 450-650 nm region, the profile and intensity of which depended on the nature and position of substituents in the phenylene fragment.

Calcifying Bacteria Flexibility in Induction of CaCO Mineralization.

Microbially induced CaCO precipitation (MICP) is considered as an alternative green technology for cement self-healing and a basis for the development of new biomaterials. However, some issues about the role of bacteria in the induction of biogenic CaCO crystal nucleation, growth and aggregation are still debatable. Our aims were to screen for ureolytic calcifying microorganisms and analyze their MICP abilities during their growth in urea-supplemented and urea-deficient media.

Crystal and Supramolecular Structure of Bacterial Cellulose Hydrolyzed by Cellobiohydrolase from 3C: A Basis for Development of Biodegradable Wound Dressings.

The crystal and supramolecular structure of the bacterial cellulose (BC) has been studied at different stages of cellobiohydrolase hydrolysis using various physical and microscopic methods. Enzymatic hydrolysis significantly affected the crystal and supramolecular structure of native BC, in which the 3D polymer network consisted of nanoribbons with a thickness ≈ 8 nm and a width ≈ 50 nm, and with a developed specific surface ≈ 260 m·g. Biodegradation for 24 h led to a ten percent decrease in the mean crystal size of BC, to two-fold increase in the sizes of nanoribbons, and in the specific surface area up to ≈ 100 m·g.