TY  - JOUR
A1  - Savitskaya, Irina
A1  - Zhantlessova, Sirina
A1  - Kistaubayeva, Aida
A1  - Ignatova, Ludmila
A1  - Shokatayeva, Dina
A1  - Sinyavsky, Yuriy
A1  - Kushugulova, Almagul
A1  - Digel, Ilya
T1  - Prebiotic cellulose–pullulan matrix as a “vehicle” for probiotic biofilm delivery to the host large intestine
JF  - Polymers
N2  - This study describes the development of a new combined polysaccharide-matrix-based technology for the immobilization of Lactobacillus rhamnosus GG (LGG) bacteria in biofilm form. The new composition allows for delivering the bacteria to the digestive tract in a manner that improves their robustness compared with planktonic cells and released biofilm cells. Granules consisting of a polysaccharide matrix with probiotic biofilms (PMPB) with high cell density (>9 log CFU/g) were obtained by immobilization in the optimized nutrient medium. Successful probiotic loading was confirmed by fluorescence microscopy and scanning electron microscopy. The developed prebiotic polysaccharide matrix significantly enhanced LGG viability under acidic (pH 2.0) and bile salt (0.3%) stress conditions. Enzymatic extract of feces, mimicking colon fluid in terms of cellulase activity, was used to evaluate the intestinal release of probiotics. PMPB granules showed the ability to gradually release a large number of viable LGG cells in the model colon fluid. In vivo, the oral administration of PMPB granules in rats resulted in the successful release of probiotics in the colon environment. The biofilm-forming incubation method of immobilization on a complex polysaccharide matrix tested in this study has shown high efficacy and promising potential for the development of innovative biotechnologies.
KW  - immobilization
KW  - prebiotic
KW  - bacterial cellulose
KW  - biofilms
KW  - Lactobacillus rhamnosus GG
Y1  - 2023
U6  - http://dx.doi.org/10.3390/polym16010030
N1  - This article belongs to the Section "Polymer Composites and Nanocomposites"
IS  - 16(1)
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Digel, Ilya
A1  - Akimbekov, Nuraly
A1  - Rogachev, Evgeniy
A1  - Pogorelova, Natalia
T1  - Bacterial cellulose produced by Medusomyces gisevii on glucose and sucrose: biosynthesis and structural properties
JF  - Cellulose
N2  - 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.
KW  - Bacterial cellulose
KW  - Medusomyces gisevi
KW  - Carbon sources
KW  - Culture media
KW  - Cellulose nanostructure
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s10570-023-05592-z
SN  - 1572-882X (Online)
SN  - 0969-0239 (Print)
N1  - Corresponding author: Ilya Digel
PB  - Springer Science + Business Media
CY  - Dordrecht
ER  -