@article{PogorelovaRogachevDigeletal.2020,
  author    = {Pogorelova, Natalia and Rogachev, Evgeniy and Digel, Ilya and Chernigova, Svetlana and Nardin, Dmitry},
  title     = {Bacterial Cellulose Nanocomposites: Morphology and Mechanical Properties},
  series = {Materials},
  volume    = {13},
  journal   = {Materials},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  isbn      = {1996-1944},
  doi       = {10.3390/ma13122849},
  pages     = {1 -- 16},
  year      = {2020},
  abstract  = {Bacterial cellulose (BC) is a promising material for biomedical applications due to its unique properties such as high mechanical strength and biocompatibility. This article describes the microbiological synthesis, modification, and characterization of the obtained BC-nanocomposites originating from symbiotic consortium Medusomyces gisevii. Two BC-modifications have been obtained: BC-Ag and BC-calcium phosphate (BC-Ca3(PO4)2). Structure and physicochemical properties of the BC and its modifications were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and infrared Fourier spectroscopy as well as by measurements of mechanical and water holding/absorbing capacities. Topographic analysis of the surface revealed multicomponent thick fibrils (150-160 nm in diameter and about 15 µm in length) constituted by 50-60 nm nanofibrils weaved into a left-hand helix. Distinctive features of Ca-phosphate-modified BC samples were (a) the presence of 500-700 nm entanglements and (b) inclusions of Ca3(PO4)2 crystals. The samples impregnated with Ag nanoparticles exhibited numerous roundish inclusions, about 110 nm in diameter. The boundaries between the organic and inorganic phases were very distinct in both cases. The Ag-modified samples also showed a prominent waving pattern in the packing of nanofibrils. The obtained BC gel films possessed water-holding capacity of about 62.35 g/g. However, the dried (to a constant mass) BC-films later exhibited a low water absorption capacity (3.82 g/g). It was found that decellularized BC samples had 2.4 times larger Young's modulus and 2.2 times greater tensile strength as compared to dehydrated native BC films. We presume that this was caused by molecular compaction of the BC structure.},
  language  = {en}
}
@article{DigelAkimbekovRogachevetal.2023,
  author    = {Digel, Ilya and Akimbekov, Nuraly and Rogachev, Evgeniy and Pogorelova, Natalia},
  title     = {Bacterial cellulose produced by Medusomyces gisevii on glucose and sucrose: biosynthesis and structural properties},
  series = {Cellulose},
  journal   = {Cellulose},
  publisher = {Springer Science + Business Media},
  address   = {Dordrecht},
  issn      = {1572-882X (Online)},
  doi       = {10.1007/s10570-023-05592-z},
  pages     = {15 Seiten},
  year      = {2023},
  abstract  = {In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) synthesized by Medusomyces gisevii have been studied. The culture medium was composed of different initial concentrations of glucose or sucrose dissolved in 0.4\% extract of plain green tea. Parameters of the culture media (titratable acidity, substrate conversion degree etc.) were monitored daily for 20 days of cultivation. The BC pellicles produced on different carbon sources were characterized in terms of biomass yield, crystallinity and morphology by field emission scanning electron microscopy (FE-SEM), atomic force microscopy and X-ray diffraction. Our results showed that Medusomyces gisevii had higher BC yields in media with sugar concentrations close to 10 g L-1 after a 18-20 days incubation period. Glucose in general lead to a higher BC yield (173 g L-1) compared to sucrose (163.5 g L-1). The BC crystallinity degree and surface roughness were higher in the samples synthetized from sucrose. Obtained FE-SEM micrographs show that the BC pellicles synthesized in the sucrose media contained densely packed tangles of cellulose fibrils whereas the BC produced in the glucose media displayed rather linear geometry of the BC fibrils without noticeable aggregates.},
  language  = {en}
}
@article{PogorelovaRogachevAkimbekovetal.2024,
  author    = {Pogorelova, Natalia and Rogachev, Evgeniy and Akimbekov, Nuraly and Digel, Ilya},
  title     = {Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates},
  series = {Journal of materials science},
  volume    = {2024},
  journal   = {Journal of materials science},
  publisher = {Springer Science + Business Media},
  address   = {Dordrecht},
  issn      = {1573-4803 (Online)},
  doi       = {10.1007/s10853-024-09596-3},
  pages     = {13 Seiten},
  year      = {2024},
  abstract  = {Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1\%, dried until a constant weight was reached) and freeze-drying (FD, treated at - 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity.},
  language  = {en}
}