Modification of microstructure and selected physicochemical properties of bacterial cellulose produced by bacterial isolate using hydrocolloid-fortified Hestrin-Schramm medium

Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including modified starches (oxidized starch-1404 and hydroxypropyl starch-1440), locust bean gum, xanthan gum (XG), guar gum, and carboxymethyl cellulose were added to the Hestrin-Schramm medium to improve the production performance and microstructure of BC by Gluconacetobacter entanii isolated from coconut water. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% XG resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. In addition, scanning electron microscopy showed that all modified films have the characteristic three-dimensional network of cellulose nanofibers with dense structure and low porosity as well as larger fiber size compared to control. X-ray diffraction indicated that BC fortified with carboxymethyl cellulose exhibited lower crystallinity while Fourier infrared spectroscopy showed characteristic peaks of both control and modified BC films.

Automated summary

In this study, various hydrocolloids were added to the Hestrin-Schramm medium to improve the production performance and microstructure of bacterial cellulose (BC) by Gluconacetobacter entanii. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% xanthan gum resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. The modified BC films exhibited a characteristic three-dimensional network structure with dense and low porosity, as well as larger fiber size compared to the control.