TY  - JOUR
A1  - Pogorelova, Natalia
A1  - Rogachev, Evgeniy
A1  - Akimbekov, Nuraly S.
A1  - Digel, Ilya
T1  - Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates
JF  - Journal of materials science
N2  - 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.
Y1  - 2024
U6  - https://doi.org/10.1007/s10853-024-09596-3
SN  - 1573-4803 (Online)
SN  - 0022-2461 (Print)
N1  - Corresponding author: Ilya Digel
VL  - 2024
PB  - Springer Science + Business Media
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Akimbekov, Nuraly S.
A1  - Digel, Ilya
A1  - Tastambek, Kuanysh T.
A1  - Kozhahmetova, Marzhan
A1  - Sherelkhan, Dinara K.
A1  - Tauanov, Zhandos
T1  - Hydrogenotrophic methanogenesis in coal-bearing environments: Methane production, carbon sequestration, and hydrogen availability
JF  - International Journal of Hydrogen Energy
N2  - Methane is a valuable energy source helping to mitigate the growing energy demand worldwide. However, as a potent greenhouse gas, it has also gained additional attention due to its environmental impacts. The biological production of methane is performed primarily hydrogenotrophically from H2 and CO2 by methanogenic archaea. Hydrogenotrophic methanogenesis also represents a great interest with respect to carbon re-cycling and H2 storage. The most significant carbon source, extremely rich in complex organic matter for microbial degradation and biogenic methane production, is coal. Although interest in enhanced microbial coalbed methane production is continuously increasing globally, limited knowledge exists regarding the exact origins of the coalbed methane and the associated microbial communities, including hydrogenotrophic methanogens. Here, we give an overview of hydrogenotrophic methanogens in coal beds and related environments in terms of their energy production mechanisms, unique metabolic pathways, and associated ecological functions.
KW  - Coal
KW  - Methanogenesis
KW  - Methane
KW  - Hydrogenotrophic methanogens
KW  - H2
Y1  - 2024
U6  - https://doi.org/10.1016/j.ijhydene.2023.09.223
SN  - 1879-3487 (online)
SN  - 0360-3199 (print)
VL  - 52
IS  - Part D
SP  - 1264
EP  - 1277
PB  - Elsevier
CY  - New York
ER  -