Controllable synthesis uniform spherical bacterial cellulose and their potential applications

Engineering nanocellulose based material through the bottom-up approach has addressed great attention. Bacterial cellulose synthesis in nature follows this concept, but it is challenging to control its morphology. In this study, various bacterial culturing parameters were assessed with the goal of assembling uniform spherical bacterial cellulose (SBC) which has advantages owing to its unique morphology and increased surface areas. The potential activation/modification of the synthesized SBC was also explored by using TEMPO-mediated oxidization and iron-induced magnetization. Our results showed that the uniform SBC was synthesized when the ratio of culture medium to flask volumes (M/F value) was kept at 50%, while the diameter of these uniform SBC could be adjusted by changing the agitation speed and flask volume. The SBC could be further TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) oxidized and iron-induced magnetized without sacrificing its spherical morphology and cellulose properties (e.g. crystallinity and degree of polymerization), which significantly improved their metal absorbability and recyclability. Our results open the door for the SBC production and application. Schematic illustration of controllable biosynthesis of spherical bacterial cellulose (SBC), preparation of activated spherical bacterial cellulose (ASBC) and magnetic activated spherical bacterial cellulose (MASBC): a controllable biosynthesis of SBC; b Activating of SBC by TEMPO-media oxidation; c Magnetization of ASBC; d MASBC.