Semi-continuous bacterial cellulose production in a rotating disk bioreactor and its materials properties analysis

A rotating disk bioreactor with plastic composite support (PCS) as the solid support was evaluated for bacterial cellulose (BCel) production. Results demonstrated that BCel can be produced in a semi-continuous manner. The BCel productivity reached around 0.24 g/L/day and can be sustained for at least five consecutive runs. Scanning electron microscopy results confirmed that Gluconacetobacter can attach on the PCS surface, which eliminates the need of reinoculation. X-ray diffraction patterns and mechanical analysis of BCel produced from this semi-continuous process exhibited lower crystallinity (66.9 %) and mechanical property (Young's modulus of 372.5 MPa) when compared with the BCel obtained from static culture (crystallinity = 88.7 %, Young's modulus of 3,955.6 MPa). Both BCel samples possessed similar water content (98.66 vs. 99.04 %) and thermostability (around 346 °C). In conclusion, the PCS rotating disk bioreactor system can be used to produce BCel in pellicle form with enhanced productivity and, meanwhile, can be scaled up easily to meet commercial need.