The facile and controllable synthesis of a bacterial cellulose/polyhydroxybutyrate composite by co-culturing Gluconacetobacter xylinus and Ralstonia eutropha

Bacterial cellulose (BC) and polyhydroxybutyrate (PHB) are microbial polymers considered to be promising biodegradable alternatives to fossil fuel derivatives. BC and PHB can be combined into a composite with enhanced mechanical properties. The synthesis processes of BC/PHB composites described until now are complicated with multiple steps. Here, BC/PHB composites were synthesized by a facile Gluconacetobacter xylinus and Ralstonia eutropha co-culture method generating BC and PHB simultaneously in situ. This co-culture approach ensured a certain level of control over the synthesis process. By simply varying the R. eutropha inoculum, the weight ratio of PHB into BC/PHB was adjusted from 15.62 to 42.88 %. The fabricated composites were networks of BC fibers connecting PHB particles. BC/PHBs were characterized by thermal and mechanical analyses and exhibited a 2.6 times higher capacity for toxic copper adsorption than pure BC. The co-culture technique described here is a simple synthesis method to obtain BC/PHB with adjustable characteristics.