B. Comparison between Static and RDR fermentation
It was clearly observed that fermentation using RDR gives consistently significant increase in microbial cellulose yield compared to static fermentation. From the experiments, two major factors that lead to increase of microbial cellulose weight in RDR were identified. The first is surface area for fermentation while the other one is aeration factors. Microbial
cellulose yield is proportional to surface area for fermentation [8]. It was mentioned that RDR with good discs packing provides better surface area compared to static fermentation which reduces the diffusion problem as in static fermentation. Figure 4 visually illustrates difussion problems in static fermentation and how RDR overcomes the problems.