Characterization of bacterial cellulose produced by the KomEt strain isolated from a kombucha SCOBY

Abstract

Bacterial cellulose (BC) is gaining interest, due to its actual and potential applications in the biomedical, cosmetics and textile industries. In this study, mechanical, thermal, and chemical properties of BC produced from a novel strain, isolated from a kombucha symbiotic culture of bacteria and yeast (SCOBY), were evaluated. The highest obtained yields with this strain, after a 10-day fermentation, were 496 ± 14 g/L (native hydrated) and 19 ± 1 g/L (dry). Compression, including relaxation, and traction tests were performed on BC membranes in a hydrated state. The tested material revealed a 3-phase compression behaviour with a compression modulus of 235 ± 50 Pa. In terms of relaxation in water, BC membranes showed plastic deformation past 50 % compression. Regarding BC membrane under traction, analysis showed a 1090 ± 410 kPa Young Modulus, a 50 ± 10 % Elongation at Break and a 270 ± 80 kPa Ultimate Tensile Strength (UTS). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated that BC begins its degradation around 290 °C. Fourier-Transform Infrared spectroscopy (FTIR) of freeze-dried BC membranes confirmed the obtained biofilm to be BC. The results of this study provide valuable information on the potential applications of BC membranes in different industries including textile, biomedical and as a low-cost alternative to some synthetic polymers.