Physicochemical properties of bacterial cellulose from a strain of Komagataeibacter intermedius and analytical...

A high bacterial cellulose (BC) producing Komagataeibacter intermedius (KEI6 strain) was isolated from water kefir grains in Xinjiang, China. Under optimized culture conditions, the KEI6 strain was able to produce BC (KEI6-BC) up to 7.03 g/L dry weight. In this study, the rheological properties, hydrophilicity, molar mass, and specific surface area of KEI6-BC were systematically evaluated and characterized by three different drying treatments (freeze-drying, drying at 50 °C, and high-pressure homogenization). The results showed that KEI6-BC has a storage modulus of 10⁴ Pa and a weight average molecular weight of 4.19×10⁵ g/mol, which exhibits a randomly curled conformational polymer structure. Interestingly, freeze-dried treated KEI6-BC exhibited a highly uniform fiber distribution as well as good functional group retention, crystallinity, and thermal stability. In addition, we used freeze-dried KEI6-BC as a carrier to load ampicillin sodium and evaluated its antibacterial activity. It was found that freeze-dried KEI6-BC was promising as a carrier for slow drug release as well as exhibited good antibacterial activity after drug loading, demonstrating its great potential as an efficient antibacterial composite film.