Synthesis and Characterization of Bacterial Cellulose from Citrus-Based Sustainable Resources.

Citrus juices from whole oranges and grapefruits (discarded from open market) and aqueous extracts from citrus processing waste (mainly peels) were used for bacterial cellulose production by DSM 15973. Grapefruit and orange juices yielded higher bacterial cellulose concentration (6.7 and 6.1 g/L, respectively) than lemon, grapefruit, and orange peels aqueous extracts (5.2, 5.0, and 2.9 g/L, respectively). Compared to the cellulosic fraction isolated from depectinated orange peel, bacterial cellulose produced from orange peel aqueous extract presented improved water-holding capacity (26.5 g water/g, 3-fold higher), degree of polymerization (up to 6-fold higher), and crystallinity index (35-86% depending on the method used). The presence of absorption bands at 3240 and 3270 cm in the IR spectrum of bacterial cellulose indicated that the bacterial strain synthesizes both I and I cellulose types, whereas the signals in the C NMR spectrum demonstrated that I cellulose is the dominant type.