Bacterial cellulose produced by Medusomyces gisevii on glucose and sucrose: biosynthesis and structural properties

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 (AFM) and x-ray diffraction (XRD). Our results showed that Medusomyces gisevii had higher BC yields in media with sugar concentrations close to 10g∙L -1 after a 18–20 days incubation period. Glucose in general lead to a higher BC yield (173g∙L -1 ) compared to sucrose (163.5g∙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.